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Perspectives on ecosystem-based approaches to the management of marine resources

Theme Section from Marine Ecology Progress Series Vol 274:269-303. June 2004. Idea and coordination: Howard I. Browman, Konstantinos I. Stergiou
                        MARINE ECOLOGY PROGRESS SERIES
   Vol. 274: 269–303, 2004                                           Published June 24
                            Mar Ecol Prog Ser




THEME SECTION

Perspectives on ecosystem-based approaches to the
     management of marine resources
        Idea and coordination: Howard I. Browman, Konstantinos I. Stergiou
 Contributors*: Howard I. Browman, Philippe M. Cury, Ray Hilborn, Simon Jennings, Heike K. Lotze,
Pamela M. Mace, Steven Murawski, Daniel Pauly, Michael Sissenwine, Konstantinos I. Stergiou, Dirk Zeller


            Introduction                 than the sum of its parts — a commendable step for-
                                   ward in-and-of itself. However, there is some disagree-
   Howard I. Browman1,**, Konstantinos I. Stergiou2        ment over whether the EAF, and MPAs, truly represent
                                   alternatives that will be any more effective in assisting
1
  Institute of Marine Research - Austevoll, 5392 Storebø, Norway
          Email: howard.browman@imr.no           us with sustainable management of marine resources
   2
                                   than historical practices. Regardless of the approach
    Aristotle University of Thessaloniki, School of Biology,
  Department of Zoology, Box 134, Thessaloniki 54124, Greece
                                   that is taken to decide upon catch limits, or on the loca-
           Email: kstergio@bio.auth.gr
                                   tion, size and number of MPAs, there will always be
                                   the complicated (and socio-economically-politically
  The urgent need to reduce the intense pressure and        charged) question of how these policies should be
destructive power that modern fishing practices apply        implemented and enforced; that is, governance (see,
to the world’s fisheries, and the oceans that support        for example, Mace 2001, Sissenwine & Mace 2003,
them, is now widely recognized (e.g. FAO 2002a,           Caddy 2004, Cochrane 2004, Stefansson 2004). To
Hilborn et al. 2003). However, there is far less agree-       address these issues, we solicited essay-style contribu-
ment over the exact levels to which fishing mortality        tions from several of the marine and fishery scientists
must be reduced and over how to reduce the indirect         who are at the forefront of the ongoing debate. Those
effects of fishing (e.g. bycatch, destruction of the         essays are presented here.
seafloor), in order to ensure sustainability of catches         We will not use space summarizing the content of
and the health of marine ecosystems. And this is to say       this Theme Section (TS)— we encourage you to read
nothing of disagreements over how these goals might         through it. Rather, we take this opportunity to high-
be achieved. It has proven all too easy for various         light some of the most important conclusions that issue
factions — including some fishery scientists — to blame       from the essays when they are taken as a whole and to
our having arrived at the current crossroads on the         add some commentary of our own. The acronyms used
ineffectiveness of existing management practices, and        in this TS are listed in Table 1.
on the scientific advice that underlies it. Driven by          In the critical recommendation of such fishery man-
these forces, and in recognition of the significant direct      agement tools as limits on maximum fishing mortality,
and collateral impacts that fishing imposes on marine        minimum spawning stock biomass, or total allowable
ecosystems, an Ecosystem Approach to Fisheries (EAF)         catch levels, fishery scientists often disagree about
is rapidly being adopted by institutions charged with        seemingly subtle (to the layman) aspects of data analy-
stewardship of the marine environment (e.g. NOAA           sis and interpretation. Although debates such as these
1999, Brodziak & Link 2002, FAO 2003, Garcia et al.         are at the core of the scientific process, the fact that
2003, Sinclair & Valdimarsson 2003). In conjunction         fishery scientists themselves do not always agree has
with this EAF is the implementation of Marine Pro-          been the focus of socio-political criticism, and is surely
tected Areas (MPAs), including marine reserves. Both         one of the reasons that advice on catch quotas is not
EAF and MPAs implicitly recognize that the value (to         often strictly heeded. In the case of the contributions to
humanity) of the whole ecosystem is much greater           this TS, written by proponents sitting on both sides of
                                   the fence, there is a convincing consensus on most of
                                   the key issues. While there is disagreement over just
**Contributions are presented in alphabetical order (by first
 author)
**The views expressed here are those of the author only
                                   © Inter-Research 2004 · www.int-res.com
 and do not necessarily reflect the official position of The
 Institute of Marine Research                    Resale or republication not permitted without written consent of the publisher
270                    Mar Ecol Prog Ser 274: 269–303, 2004




how severely depleted some fish stocks are, and on       of accuracy, yet we have somehow all learned to live
whether and how quickly they will recover, all agree      with that, and take appropriate precautions nonethe-
that many stocks are overexploited. While there is       less. In the face of this analogy, we must ask: why does
some disagreement over just how much fishing must       society have higher expectations of fishery scientists
be reduced, all agree that current levels of overcapa-     with respect to their ability to accurately predict the
city in the world’s fishing fleets are not sustainable.    numbers of fish that will be in the sea several years into
While there is disagreement over equating MPAs and       the future? Further, why is it so difficult for fishery sci-
EAF, all agree that MPAs will complement other man-      entists to convince society, authorities, and stakehold-
agement tools, within an EAF or not. Thus, for each      ers to take a precautionary approach towards the
and every major issue, while there might be disagree-     management and conservation of fish stocks (or whole
ment on the details, there is unanimity over the press-    ecosystems) (see Lotze’s contribution to this TS)?
ing need for action to protect marine ecosystems. And     Finally, if people are routinely relocated to a safe place
that must be made the focus of public attention.        when a potentially destructive storm is coming, why is
  Iles (1980) refers to ‘…a ‘Bio-Energetic Multi-Species   it so difficult to recognize the inherent rights that
Ecosystem Dynamics (BEMUSED)… ’ basis for setting       marine fauna have to a safe haven (in the form, for
catch quotas. This illustrates how the idea of taking an    example, of MPAs)? The international treaty repre-
EAF is really nothing new, and it highlights that,       sented by the Montreal Protocol on Substances that
unless we are truly more clever (and richer with data)     Deplete the Ozone Layer is another example of how
than we were almost 25 yr ago, following EAF could       society can respond when the stakes are high and the
                                need is urgent: society can adopt and implement pre-
leave us just as bemused, and/or muddled (see Hedg-
peth 1977). Iles (1980) also stated that ‘…social, politi-   cautionary approaches to the management of the
cal, and economic factors are at least as important in     world’s resources, even when there are complex mix-
fisheries management as the scientific knowledge of      tures of stake holders. Hopefully, we will be able to
the resource.’ This conclusion, arrived at 24 yr ago, is    achieve the same for the world’s marine ecosystems.
reiterated by several contributors to this TS — gover-
nance, and not science, remains the weakest link in the
                                  Table 1. Acronyms and their full forms used in the TS
management chain (also see Hutchings et al. 1997,
Harris 1998, Policansky 1998, FAO 2003, Cochrane
2004). Thus, even if we were able to provide managers      Abbreviation/        Full name
                                 acronym
with perfect scientific prediction, that alone will not
help. Following from all of this, if there is any hope of
                                 BEMUSED     Bio-Energetic Multi Species Ecosystem
succeeding with an EAF, or any real chance of control-              Dynamics
ling fishing, the organizations and institutions involved    CML       Census of Marine Life
                                 EAF       Ecosystem Approach to Fisheries
in the governance of marine resources will have to be
                                 EEZ       Exclusive Economic Zones
totally revamped. The new structure will have to in-
                                 FAO       Food and Agriculture Organization
clude stakeholders, social and political scientists, econ-    GIS       Geographic Information System
omists, lawyers, political lobbyists, educators, journal-    GLOBEC     Global Ocean Ecosystem Dynamic Programs
ists, civil engineers, ecologists, fishery scientists and    GOOS      Global Ocean Observing System
                                 ICES      International Council for the Exploration of
oceanographers, all operating in a conciliatory and
                                         the Sea
integrative environment.
                                 ICNAF      International Convention for the Northwest
  We hope that the following analogy will illustrate              Atlantic Fisheries
that it is untenable to ignore the counsel of fishery      ITQ       Individual Transferable Quotas
                                 IUCN      International Union for the Conservation of
scientists, even when they disagree and/or provide
                                         Nature
advice that is based upon highly uncertain assess-
                                 LME       Large Marine Ecosystem
ments (also see Stefansson 2004). If meteorologists say     MPA       Marine Protected Areas
that a major storm is coming, people are relocated to      MSY       Maximum Sustainable Yield
safer places, and houses and buildings are boarded        MVH       Member-Vagrant Hypothesis
                                 NOAA      National Oceanic and Atmospheric
up. Even if the predictions about when and where
                                         Administration
the storm will hit — provided by extensive networks
                                 OECD      Organisation for Economic Co-operation and
of expensive ground-based monitoring devices and                 Development
weather satellites — are not very accurate (because the     PISCO      Partnership for Interdisciplinary Studies of
                                         Coastal Oceans
storm’s behaviour is unpredictable), precautions are
                                 UNDP      United Nations Development Plan
still taken, often over a very wide geographic area…
                                 UNEP      United Nations Environmental Programme
just in case. This illustrates that society does not expect   TAC       Total Allowable Catch
meteorologists to predict the weather with any degree
                                                               271
             Theme Section: Ecosystem-based approaches to management of marine resources




  Marine Protected Areas as a central                compared, among others. Clearly, the choice of loca-
                                   tion, spatial extent (horizontal and vertical), and num-
element of ecosystem-based management:
                                   ber of MPAs is critical if they are to meet these goals.
defining their location, size and number
                                   It is to this issue that we devote our attention here.
   Howard I. Browman1,*, Konstantinos I. Stergiou2          Halpern & Warner (2003) state, ‘Most reserve locations
                                   and boundaries were drawn by a political process that
1
  Institute of Marine Research - Austevoll, 5392 Storebø, Norway
                                   focused on economics, logistics, or public acceptance,
          Email: howard.browman@imr.no
                                   while largely overlooking or ignoring how the complex
   2
    Aristotle University of Thessaloniki, School of Biology,
                                   ecology and biology of an area might be affected by re-
  Department of Zoology, Box 134, Thessaloniki 54124, Greece
                                   serve protection.’ In this sense, establishing the locations
           Email: kstergio@bio.auth.gr
                                   and boundaries of MPAs can be seen as analogous to the
  Marine Protected Areas (MPAs) include many sub-          imperfect process associated with establishing stock
classes (e.g. marine sanctuaries, marine parks, wildlife       management grids — a process that has never really
refuges, fisheries closures, no-take MPAs, multiple-use       managed to incorporate the key realities of population
MPAs, marine reserves, ecological reserves) all of          dynamics of the exploited species. While there is a
which can be defined based mainly upon the level           growing consensus on the need for MPAs, at this point in
of protection and the primary conservation goal (see         time there is no clear and well-founded basis upon
www.mpa.gov; Lubchenco et al. 2003). MPAs, and            which their location, spatial extent and number can be
especially the marine reserves subclass (i.e. ‘areas of the     decided. In fact, rationales/frameworks that are based
ocean completely protected from all extractive and          upon principles of theoretical and applied ecology have
destructive activities’; Lubchenco et al. 2003) represent      only recently been tapped to address these key ques-
the extreme case of the precautionary approach to          tions (e.g. Roff & Evans 2002, Botsford et al. 2003,
managing marine resources (e.g. Lauck et al. 1998).         Roberts et al. 2003a,b, Shanks et al. 2003, Fisher & Frank
  The strong and rapidly growing interest in MPAs          2004). Much of this work focuses on the manner in which
(and particularly in marine reserves) is reflected in the      different aspects of the life histories of marine organ-
dramatic increase in the number of publications           isms — spawning locations, dispersal, larval retention
devoted to them (reviewed in Jones 2002, Gell &           and export, juvenile nursery areas, etc.— affect MPA
Roberts 2003, and the articles in ‘The Science of          design. In this context, we contend that an eco-
Marine Reserves’, a supplemental issue of Ecological         evolutionary framework already exists, grounded in
Applications, Vol 13, Iss 1, freely available for down-       marine ecology and fisheries oceanography, that is
load at www.esa-journals.org/esaonline/?request=get-         completely consistent with EAF and MPA objectives.
static&name=s1051-0761-013-01-0001). In addition,            The Member-Vagrant Hypothesis as a framework for
there are now a number of sites on the World Wide          defining the location, size and number of MPAs. The
Web that are either totally devoted to MPAs, or include       Member-Vagrant Hypothesis (MVH), the development of
relevant information on them: UNEP’s World Con-           which can be traced through a series of publications by
servation Monitoring Centre (www.unep-wcmc.org/           Mike Sinclair and Derek Iles (Iles & Sinclair 1982, Sinclair
protected_areas), the Partnership for Interdiscipli-         1988, 1992, Sinclair & Iles 1988, 1989), defines 4 attributes
nary Studies of Coastal Oceans (PISCO, www.             of populations that are involved in the regulation of their
piscoweb.org), and several others. This intense interest       size. The ’population richness’ refers to the number of
is at least partly related to MPAs having been identi-        discrete self-sustaining populations (henceforth simply
fied and advocated as a conservation (of habitat and         ’populations’) exhibited by any given species. Species
biodiversity) and managerial (of fisheries) tool of cen-       such as herring, cod, mackerel, the salmonids, and many
tral importance in the Ecosystem Approach to Fisheries        others are population rich. The ‘spatial pattern’ relates to
(EAF) (e.g. Agardy 2000, Stergiou 2002, Halpern &          the geographic distribution of these populations. Popula-
Warner 2003, Lubchenko et al. 2003, Pauly & MacLean         tion rich species are usually also broadly distributed (the
2003, Hilborn et al. 2004). It is hoped that MPAs will be      north Atlantic region is so far the best studied in this
beneficial in (1) rebuilding overexploited fish stocks,       regard). Population richness and spatial pattern are
(2) preserving habitat and biodiversity, (3) maintaining       species-level characters. The ’absolute abundance’ refers
ecosystem structure, (4) buffering against the effects of      to the instantaneous size of the various populations of any
environmental variability, (5) serving as a control group      given species, and this size — which can range over
against which populations in exploited regions can be        several orders of magnitude — varies over time (thus, its
                                   ’temporal variability’). These last 2 components of the
                                   MVH are population-level characteristics. Sinclair & Iles
*The views expressed here are those of the author only
and do not necessarily reflect the official position of The     have applied the MVH to describe the richness, pattern,
Institute of Marine Research                    abundance and variability of several economically im-
272                     Mar Ecol Prog Ser 274: 269–303, 2004




portant fish including herring, cod, haddock, mackerel,     balanced reliance upon MPAs as a fisheries management
and several others. For all of these, (1) the population     tool (see Hilborn et al. 2004 and several of the contribu-
richness is directly correlated with the number of reten-    tions to this TS). Nonetheless, if the choice of their loca-
tion areas for the species’ early life history stages (also   tion, size and number is well grounded in marine ecology
implying that the adults are able to return to the same     and fisheries oceanography, then MPAs stand to become
                                 an effective tool for conservation and management. In or-
geographic locations); (2) the spatial pattern is related to
the number of discrete geographic areas allowing closure     der for this to be realized, 2 closely related steps are re-
of the species’ life cycle; (3) the absolute abundance is    quired. First, an operational spatial unit within which
scaled according to the size of the geographic area in      MPAs will be embedded must be defined. Such a unit al-
which there is closure of the life cycle (corroborated by    ready exists: the Large Marine Ecosystem (LME) (e.g.
MacKenzie et al. [2003], who reported that the biomass      Sherman & Duda 1998). LMEs are large ‘regions of ocean
of cod spawners and recruits is related to habitat size);    space encompassing coastal areas from river basins and
(4) the geographic locations referred to in (1), (2) and     estuaries to the seaward boundaries of continental shelves
(3) have distinct oceanographic features; and (5) the tem-    and the outer margins of the major current systems’ char-
poral variability is determined by the intergenerational     acterized by ‘distinct: (1) bathymetry, (2) hydrography,
losses of individuals from any one population (through      (3) productivity, and (4) trophically dependent popula-
mortality and/or passive processes such as advection or     tions’ (www.lme.noaa.gov). When combined with Long-
spatial constraints = ’vagrancy’). It is worth noting that the  hurst’s (1998) ‘Biogeochemical Provinces’, which extend
MVH is completely consistent with the metapopulation       out into the open ocean areas, LMEs can provide a very
concepts that have recently been applied to marine fish     useful ecosystem framework for fisheries research (see
populations (e.g. Smedbol & Wroblewski 2002)           Pauly & MacLean 2003, www.seaaroundus.org). Second,
  Exploited populations are subject to intense size-      future work in fisheries science could adopt a more eco-
dependent mortality and drastic reductions in biomass      logical/oceanographic orientation, by (1) identifying and
over a short time and a large spatial scale (e.g. Chris-     mapping the key faunistic components and the biodiver-
tensen et al. 2003, Myers & Worm 2003, Pauly & MacLean      sity ‘hot spots’ (sensu Worm et al. 2003) in the main
2003). With modern fishing practices and equipment, this     ecosystems of the world’s oceans (as defined above);
can impact a large proportion of the populations in a      (2) describing the life cycles of these key components
species’ entire spatial pattern. Thus, commercial fishing    within the context of the MVH framework; (3) spatially
imposes new conditions on these populations and, there-     mapping the life cycles of key species (see Zeller & Pauly
fore, drastically affects all 4 MVH population attributes.    2001); and (4) identifying the special oceanographic fea-
  The MVH ‘…emphasizes that membership in a popu-        tures associated with the retention and nursery areas of
lation in the oceans requires being in the appropriate      these key components (recent work linking population
place during the various parts of the life cycle. It implies   genetics with marine ecology and fisheries oceanography
that animals can be lost from their population, and thus     holds promise in this regard, e.g. Reiss et al. 2000).
become vagrants. Life cycles are considered as continu-
                                 Acknowledgements. For their influences on our development
ity solutions within particular geographical settings
                                 as marine scientists, we dedicate this essay to Maxwell J.
which impose spatial constraints.’ (Sinclair & Iles 1989,
                                 Dunbar (deceased), T. Derek Iles, William C. Leggett, Brian
p. 169). Thus, for many marine fishes, population rich-     M. Marcotte and Michael Sinclair. We thank K. Erzini, K. T.
ness, pattern, absolute abundance and temporal vari-       Frank, J. J Govoni, and D. Pauly for their comments on the
                                 manuscript. H.I.B.’s ongoing research, and his editorial
ability are all a function of geography.
                                 activity for MEPS, is supported by the Institute of Marine
  Following from the MVH, the location of MPAs should
                                 Research, Norway, and by The Research Council of Norway.
be chosen to include a subset of the populations within
a species’ (or species complex) spatial pattern. The size
of each such MPA would then be assigned based upon
                                 Tuning the ecoscope for the Ecosystem
the geographic area within which the corresponding
population’s life history can achieve closure. In our           Approach to Fisheries
view, applying the MVH in this manner would satisfy
                                           Philippe M. Cury
many of the objectives of MPAs.
  It has only recently been possible to assess whether      Institut de Recherche pour le Développement (IRD), CRHMT
MPAs do in fact provide the benefits listed above (re-              BP 171, 34203 Sète Cedex, France
                                          Email: philippe.cury@ird.fr
viewed in e.g. S. J. Hall 1998, Jones 2002, Gell & Roberts
2003, Halpern & Warner 2003, Luchenco et al. 2003,
Hilborn et al. 2004). These assessments have led to argu-     A multidisciplinary scientific approach is needed
ments over the degree to which MPAs can or will succeed.     for the Ecosystem Approach to Fisheries (EAF). The
There is also some concern over the possibility of an im-    Reykjavik Declaration of 2001, reinforced at the World
                                                          273
           Theme Section: Ecosystem-based approaches to management of marine resources




Summit of Sustainable Development in Johannesburg      applied to solve specific scientific problems or to respond
in 2002, requires nations to base policy related to     to questions of importance to society.
marine resource exploitation on an ecosystem approach.     Using the telescope and microscope as analogies, the
To fulfil this new requirement, a strategy based upon    term ‘ecoscope’ was proposed by Ulanowicz (1993) to
innovative science that will address the complexity of   characterize ecosystem modelling that may be used as a
marine ecosystems, coupled with operational frame-     tool for resolving patterns, indicative of the key ecosys-
works for an effective EAF is needed. EAF must be      tem responses (that may otherwise be obscured within
built on a scientific rationale that will link ecological  the complexity of marine ecosystems). Today there exists
processes to ecosystem-level patterns. In doing so, it   no general, unified theory of the functioning of marine
will help managers to recognize and understand eco-     ecosystems, nor a single tool on which a reliable ‘eco-
logical limits to avoid the loss of ecosystem integrity   scope’ can be based. Moreover, in the context of global
and to maintain fisheries in viable states (Fowler &    changes (i.e. climate change and overexploitation), the
Hobbs 2002, Mullon et al. 2004).              exercise is even more difficult as we are facing changes
  This is a challenging task, as marine ecosystems are   and fluctuations on a global scale that have not been ex-
difficult to define, having no apparent boundaries,     perienced before (Holling 1995). To respond to these
and lacking the clear objective or purpose that can     challenges, the ecoscope must be operationalized into an
be ascribed to more tractable biological or ecological   integrative framework for studying marine ecosystems
entities (e.g. individuals or populations). An ecosys-   and responding to the needs of the EAF. I discuss below
tem contains water, nutrients, detritus, and numerous    how we can start implementing this approach.
kinds and sizes of organisms ranging from bacteria,      Linking patterns to processes. Strong ecological
phytoplankton, zooplankton, and fish to mammals       patterns have been described in marine ecosystems
and birds, all with their own life history traits. These  (Parson 2003). The mechanisms explaining alternation
living and non-living ecosystem components are       between different pelagic fish populations, synchrony
interconnected through continuously changing food      between remote fish populations, and regime shifts
webs, which make ecological systems extraordinarily     still remains largely speculative in the marine environ-
complex.                          ment contrary to studies in lake ecosystems (Carpenter
  Today, the explicit study of complexity is both neces-  2003). I will use the example of regime shifts that rep-
sary and timely in ecology (Loehle 2004). Emergence     resent a crucial ecological pattern for the EAF, as they
has replaced the earlier mostly theoretical approach to   are sudden changes in structure and functioning of
implementing classical population dynamics in ecol-     marine ecosystems that affect several components,
ogy (Woods 2004). The concept of simple cause and      exploited or not. For example, shifts from demersal fish
effect is neither adequate nor sufficient when dealing   dominated to pelagic fish dominated ecosystems (or
with complex systems, particularly if one accepts the    short-lived species such as shrimps, crabs or octopus)
principle that prediction is a pre-requisite for applied  have been documented in the Atlantic and the Baltic
ecological research (Peters 1991). Research in ecology   (Worm & Myers 2003); shifts from fish-dominated to
has been based mostly on studying processes in detail,   jellyfish-dominated ecosystems have been observed in
resulting in an impressive number of potential cause-    the Bering Sea, the Black Sea, the Gulf of Mexico,
effect relationships to explain emergent patterns.     the western Mediterranean Sea, Tokyo Bay and off
Emerging patterns suggest likely tendencies and pos-    Namibia (Parsons & Lalli 2002). These regime shifts
sible response trajectories. A combination of the pro-   have deeply modified marine ecosystems and the fish-
cess and emergence approaches has long been advo-      eries they sustain. EAF requires understanding the
cated (Elton 1927), but with relatively little success,   nature of such ecosystem changes, i.e. the processes
despite its promise of ameliorating our understanding    that are involved, the speed at which they act, their
of marine ecosystems.                    potential reversibility and periodicity...
  Many tools, information systems and models have       Linking processes to patterns. Regime shifts have
been developed, particularly during the last decade,    been related mainly to climatic changes, but anthro-
such as coastal hydrodynamic models, individual-based    pogenic influences also play a major role in inducing
models that couple physics and ecology, Geographic In-   ecosystem changes. A regime shift may be environmen-
formation System (GIS) and ecosystem models. These     tally driven (e.g. through bottom-up control of the food
various techniques, in many cases highly sophisticated,   web, or via direct effects on recruitment), ecologically
offer a unique opportunity in ecology to address the    driven (e.g. through competition, predation), mediated
complexity of marine ecosystems in a diverse and con-    behaviourally (e.g. behavioural adaptations to habitat
trasted manner. Despite the variety of techniques that   change) or driven by human exploitation of selected
can help track spatial and dynamical changes in eco-    species or preferential fish size classes (Cury & Shannon
systems, it is often unclear, however, how these can be   2004).
274                   Mar Ecol Prog Ser 274: 269–303, 2004




  Environmental processes act at different scales and     We need to encourage research in this direction and
probably simultaneously affect most species within      assemble processes and patterns in the same frame-
the ecosystem. Under bottom-up control, a major       work to explore the impact of global changes in time
environmental change can alter the ecosystem’s pri-     and space. The ‘ecoscope’ can be tuned to disentangle
mary productivity and, thereby, the flow of energy to    realities and speculations by assembling our present
higher trophic levels. Climatic variability can itself    biological, ecological, modelling, and operational tools
trigger a series of concomitant physical and biological   (GIS; indicators). The ‘ecoscope’ would not rely on a
processes in the form of system wide ‘regime shifts’     single model, but would incorporate a suite of models
(Hare & Mantua 2000). Mesoscale events can trigger      that can use different assumptions for depicting in a
huge variability in pelagic fish recruitment success     robust manner the relevant processes.
(Roy et al. 2001). In upwelling systems, a small num-      With the rapid development of models, methods and
ber of pelagic fish species occupy the intermediate     hypotheses, there already exists a large variety of
trophic level, feeding mostly on phytoplankton and/or    complementary approaches and tools. The ‘ecoscope’
zooplankton. These species can attain huge bio-       encompasses all of our expertise and knowledge on
masses, which can vary radically depending upon the     marine ecosystems; however, it needs to be built
strength of the environmental factors driving recruit-    around key scientific questions and information sys-
ment. The role of dominant pelagic fish has been       tems. Global changes that affect marine ecosystems,
emphasized as they might exert major control on       such as overexploitation and climate change, are rele-
energy flow, both up and down the food web; this has     vant scientific problems and effectively addressing
been termed ‘wasp-waist control’ (Cury et al. 2000).     these is crucial for sustainable development. Spatial
Predation is a fundamental process that is sometimes     and temporal dynamics that link the different organi-
as important as resource limitation in controlling      sational levels need to be tackled in any EAF. Dynam-
ecosystem dynamics. As most fish species interact      ical information systems should represent the converg-
through predation, the existence of top-down control,    ing point around which specific questions can be
through which the lower levels of the food web are      raised and discussed within the different disciplines.
regulated by 1 or several upper-level predators,       It is a stimulating task for the future, as it requires
appears to initiate trophic cascades in several marine    macroecological studies of the oceans to characterize
ecosystems (Cury et al. 2003). Fisheries tend to       patterns of ecosystem components, based on large
remove top-down forces by preferentially exploiting     amounts of data (Parsons 2003). A suite of field, exper-
large top predators in marine ecosystems, a mecha-      imental and modelling approaches is required to iden-
nism known as ‘fishing down the food web’ (Pauly et     tify, with a high degree of confidence, the underlying
al. 2000). This mechanism can result in an increase in    processes and emergent patterns. Gathering of fish-
the abundance of small forage fish (or short-living     eries and ecosystem data has, to date, mostly been
species) and to a stronger effect of climate on       undertaken separately and by different sub-groups
depleted marine resources (Beaugrand et al. 2003,      of marine scientists, with little exchange. Long-term
Cury & Shannon 2004). All of the processes that are     data series are needed to develop data banks for eco-
associated with environmental or anthropogenic forces    logical and climatologically quality control. We also
should be related in a more organized manner to the     necessitate developing new observation systems by
observed patterns of change in marine ecosystems. In     recognizing that ecological and biological data that are
order, for example, to arrive at a useful level of gener-  collected for single-species fisheries management are
alization, the respective roles of top-down, bottom-up    necessary but insufficient for understanding ecosystem
or wasp-waist forces need further exploration.        dynamics. Ecosystem-based indicators can simplify,
                               quantify and inform about the complexity of marine
  The ‘ecoscope’ as a multidisciplinary dynamical
tool to move towards an EAF. Theories, models, and      ecosystems. The elaboration and evaluation of ecosys-
observations of the patterns that are important for     tem-based indicators — such as the Fishing-in-Balance
ecosystem dynamics need to be linked (Scheffer &       index (Pauly et al. 2000) or those related to size spectra
Carpenter 2003). Ecologists have been analyzing eco-     (Shin & Cury 2004) — pertain to a multidisciplinary
logical interactions in 2 different, and often mutually   field of research on the marine ecosystem and may
exclusive, ways using reductionist (process-oriented)    constitute a central focus for fisheries management.
or holistic (pattern-oriented) approaches. However, as    This represents a new framework that would challenge
stated by Elton (1927), a combination of the 2 methods    the difficulties of understanding the dynamics of com-
would be better. Seventy-five years later, this remains   plex systems at appropriate scales by enabling repeat-
the approach that should be applied in future research    able patterns to be tracked by indicators, and by incor-
on ecosystem dynamics. The ecoscope could be one       porating existing scientific knowledge on processes
such set of tools.                      into models and ultimately into fisheries management.
                                                             275
           Theme Section: Ecosystem-based approaches to management of marine resources




  The ecoscope for EAF should rely on 3 complementary     (Jackson et al. 2001, Myers & Worm 2003), the destruc-
components: (1) a clear identification of the long-term     tion of marine habitat (Watling & Norse 1998) and
objectives (what we want and do not want to happen in      changes in ecosystems that are possible precursors to
marine ecosystems and for the exploitation of marine      future collapse (Pauly et al. 1998). The central theme
resources); (2) a multidisciplinary scientific expertise    of this ‘Litany’ is that conventional single species
(data, theory, experiments, models) to address the im-     fisheries management has failed and new approaches
pact of global changes on marine ecosystems, and that is    are needed. A major element of the proposed new
articulated around dynamical information systems, such     approaches is a move from conventional single-species
as maps and indicators, to stimulate interactions be-      management to ‘ecosystem-based management’ (NRC
tween disciplines; and (3) an evaluation of the perfor-     1998). The specific proposed solutions that emerge
mance of the ecoscope to solve scientific questions and     from the Litany include (1) elimination of subsidies for
to address management objectives for the EAF.          fishing fleets, (2) reduction of target fishing mortalities,
  Building ecoscopes is a demanding way of integrat-      (3) protecting a significant portion (20 to 30%) of the
ing knowledge and the necessary ‘ingredients’ and        world’s marine areas from fishing in the form of Marine
tools to begin the process are already available. How-     Protected Areas (MPAs) (Pauly et al. 2002), and (4)
ever, our marine and fisheries institutions are not cur-    elimination of destructive fishing practices (bottom
rently organized to undertake this integration and will     trawling). These approaches require a powerful cen-
have to address ecosystem issues by developing a        tralized government and are, therefore, unlikely to
multidisciplinary scientific approach. This integration,    be implemented in most of the developing world.
which could be achieved in an incremental way, will        While papers subscribing to the Litany seem to have
substantially improve the perception of ecological       near exclusive access to the pages of the most presti-
research and its usefulness to society. However, it is a    gious journals, their conclusions are strongly contested
task that will compete with other scientific priorities at   within the scientific community. For example, the con-
national levels, as it will require mobilizing efforts. Our   tention that the predatory fishes of the ocean have
society seems to be more interested in, and fascinated     declined by 90% (Myers & Worm 2003) and, by impli-
with, developing ‘telescopes’ rather than building       cation, that these fisheries have collapsed, has been
‘ecoscopes’. Marine ecosystems sustain our terrestrial     challenged on both the technical nature of the analysis
life and deserve priority. We need telescopes and        of fishermen’s catch records (Walters 2003) and
microscopes, but we also need ecoscopes. Implement-       detailed analysis of the fisheries (www.soest.hawaii.
ing and operationalizing ecoscopes will crystallize our     edu/PFRP/large_pelagic_predators.html). More sim-
present scientific knowledge. It requires agreement       ply, the catch data from these fisheries show that they
upon clear and perceivable objectives and adjustment      are providing increasing yields, quite contrary to what
of multiform scientific expertise to societal issues. The    one would expect from fisheries that Myers & Worm
potential task is overwhelming, and we need to take       (2003) classify as having collapsed 20 to 30 years ago.
pragmatic steps before fully implementing an EAF.         The contention that MPAs would significantly bene-
Tuning the ecoscope should help us to move towards       fit fisheries yields is equally contested (Norse et al.
‘ecosystem ecology’ as a discipline in its own right, and    2003, Hilborn et al. 2004). Nevertheless, the Litany has
towards an effective EAF.                    dominated public perception of fisheries problems and
                                other authors citing the Litany frequently say that
Acknowledgements. Thanks to Dr. Lynne Shannon, who dis-
                                70% of the world’s fish resources are overexploited or
cussed and elaborated with me the ideas that are contained in
                                collapsed, rather than fully exploited, overexploited or
this essay, and Vera Agostini, Yunne Shin, Andy Bakun,
                                collapsed. For example, ‘According to various official
Audrey Colomb, Jean Lefur and Ian Perry for their comments.
                                reports, three-quarters of the world’s fish stocks have
                                been depleted. Official statistics may well err on the
Ecosystem-based fisheries management:              conservative side: overall catches are declining, yet
    the carrot or the stick?                illegal fishing is increasing. The net result is a crisis for
                                natural fisheries.’ (O’Riordan 2003). In fact, most of the
            Ray Hilborn               world’s fisheries are not overexploited and continue to
                                be quite productive (FAO 2002a). Within the U.S., only
  School of Aquatic and Fishery Sciences, Box 355020,
 University of Washington, Seattle, Washington 98195, USA   about 16% of potential yield is being lost due to over-
        Email: rayh@u.washington.edu          fishing (Hilborn et al. 2003).
                                  The scientific objections to the Litany are primarily a
 In the last few years, a series of papers have been      matter of degree. No one questions that the majority of
published in high-profile scientific journals describing    the world’s fisheries are heavily used, many are over-
the role of fishing in the collapse of marine ecosystems    fished, some have collapsed, and good biological and
276                    Mar Ecol Prog Ser 274: 269–303, 2004




economic management suggests substantial reduc-        agement is not single-species management, but the
tions in fishing pressure are needed for sustainable     top-down control as conventionally practiced. In most
management (Hilborn et al. 2003). The major disagree-     of the world’s fisheries, the commercial and recre-
ments over possible solutions are not so much where      ational fishermen have significant political power and,
we would like to be, but how to get there. The form of    hence, attempts to impose regulations that are con-
ecosystem management that emerges from the Litany       trary to their economic interests will most likely fail.
is one that concentrates on the ecosystem in which the    Ecosystem management that relies on top-down con-
fish are embedded and relies on strong central govern-    trol for implementation, and makes no allowances for
ment control. I, and others (Garcia et al. 2003, Sissen-   the social/political dynamics of the regulatory struc-
wine & Mace 2003), believe that we need a form of       ture, is no more likely to succeed than conventional
ecosystem management that emphasizes the interac-       single species management.
tion between fish, fishermen and government regula-       What is missing from the conventional single species
tors and concentrates on incentives and participation     fisheries management approach is (1) a form of marine
with user groups. This difference can be considered as    tenure — where individuals or groups of fishermen are
a choice between a participatory approach with incen-     guaranteed a specific share of future catch — for users
tives as a ‘carrot’, and a centralized government using    that reconciles their economic interest with long-term
regulations as a ‘stick’.                   conservation, eliminates the race-for-fish, and reduces
  The key elements of the current fisheries management    or eliminates incentives for overcapitalization of fish-
approach used in most regulated fisheries in developed    ing fleets, (2) recognition that MSY is a poor fisheries
countries and international agencies include (1) single    management objective and that economic and biologi-
species stock assessment to calculate the Maximum       cal outcomes are better when catches are below MSY
Sustainable Yield (MSY) for each stock, (2) a political    and stock sizes consequently higher, (3) direct involve-
process to set regulations that determine allowable      ment of stakeholders in data collection, data analysis,
time, area, gear and catch limits that intertwines alloca-  and decision making, (4) setting the spatial scale of the
tion between users and conservation, (3) regulation      data collection, science, and management appropriate
on large spatial scales, (4) a centralized management     to the spatial scales of the fish and the fishermen, and
structure for science, decision making and enforcement    (5) management agencies that explicitly strive for
with costs paid by governments, and (5) involvement      harvesting capacity to match the long-term productive
of stakeholders primarily through the political or legal   capacity of the resource.
process. It should be noted that most stocks world-wide     The central theme of this paper is that, by consider-
are not managed in any meaningful way, and any pro-      ing humans in ecosystem management, we recognize
posals for management, ecosystem or otherwise, need      that appropriate incentives can stop the race-for-fish
to be achievable. To argue that we need more data-      and eliminate or reduce most of the current problems
intensive management and more regulation by central      in fisheries management. In the sections below I
governments in the fisheries of the world that have little  explore the nature of incentives, and how incentives
data and little regulation is untenable.           interact with other aspects of fisheries management
  There have been a wide range of papers dealing       including MSY, institutional structure, and single
with ecosystem management and each of these has        species management.
a distinct flavor. The ‘ecosystem management’ I de-       Incentives. When there is a race-for-fish, fishermen
scribe here shares elements with the views of others,     increase their incomes by fishing harder, building
all of whom emphasize various forms of marine tenure     bigger boats and catching fish before someone else
and the dynamics of fishing fleets and regulators. The    does. There is no individual economic incentive for
primary difference between the incentives approach      conservation. With various forms of marine tenure,
and the forms of ecosystem management emerging        conservation of the resource is in the individual fisher’s
from the Litany is governance. The solutions proposed     economic interest. The strongest form of tenure is
by the Litany rely on strong top-down control to       resource ownership, which is the oldest form of fish-
determine objectives and management actions and to      eries management in much of the world, found in
assure compliance by fishing industries. The incen-      community control of fishing grounds in the western
tives approach recognizes that fisheries are dynamic     Pacific (Johannes 2002) and now used as the primary
systems comprised of people and fish (Harris 1998),      management system in Chilean artisanal fisheries
that top-down control is highly limited in most fish-     (Castilla & Fernández 1998). A different form of owner-
eries, and that good outcomes result from creating      ship is allocation of fishing rights by the state through
incentives that make the interest of the participants in   high access fees or auction as is practiced in the Falk-
the fishery consistent with the interest of society as a   land Islands (Barton 2002) and in Washington State for
whole. What has failed in conventional fisheries man-     management of geoduck.
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           Theme Section: Ecosystem-based approaches to management of marine resources




  This contrasts with conventional management in      ginning with the Law of the Sea, and later through
which the state gives away the rights to fish and then   national legislation in many countries, MSY became
uses tax revenue to manage the fishery. When high      firmly enshrined as the default objective of fisheries
access fees are charged, the state has both the incen-   management. The result is that management agencies
tive and the revenue to implement stringent top-down    now try to determine the maximum yield that could
control. Tenure granted to cooperatives is another     possibly be obtained from a fish stock, and regulatory
mechanism to stop the race-for-fish since it allows the   agencies try to set catch limits at the maximum that
cooperatives to concentrate on economic maximization    could be harvested. This ignores the fact that the
of yield from the fishery. Coops have been imple-      economic optimum is almost always at yields lower
mented for hake and pollock on the west coast of the    than the MSY, and involves less fishing pressure. Once
U.S., for salmon in the Chignik area of Alaska, and for   the race-for-fish is eliminated, the fishing industry
several fisheries in Mexico. The most broadly used     recognizes that it is better served by higher stock size
form of marine tenure is individual quotas in which     and, consequently, higher catch-per-hour fished as
a specific portion of the total catch is allocated to    well as lower, but more stable catches. MSY is often
individuals or vessels. Individual Transferable Quotas   incompatible with economically viable fisheries.
(ITQs), under which individuals can catch and/or sell     Political decision making and stakeholder involve-
their right to catch a portion of the total allowable    ment. The track record of most fisheries management
catch, have now been implemented in New Zealand,      agencies is not good, and this failure has often been
Australia, Iceland and several specific fisheries within  blamed on the participation of self-interested stake-
the U.S. and Canada. ITQs, like other forms of marine    holders in the decision-making process. This has led
tenure, provide incentives to reduce fishing capacity    to frequent calls for ‘science based management,’ in
to a level appropriate for productive capacity of the    particular for the elimination of commercial and recre-
resource and to concentrate on minimizing costs and     ational fishermen from the decision making process. I
maximizing value of the catch, since the total catch is   argue that the major problem with political decision
determined by a science-based public process (NRC      making as commonly practiced is that the allocation
1999a).                           between competing groups (nations, gear types, com-
  Single species management. A major element in the    munities) and the questions of conservation and sus-
Litany is a list of fisheries collapses that includes the  tainability are not distinguished. As most fisheries
sea otter, the great whales, the northern cod, and     involve individuals or groups competing for a share of
bluefin tuna (NRC 1999). In fact, none of these really   the fish, the agencies often spend almost all their
illustrate that single species management cannot work.   energy on allocation between competing users. Once
Rather, they are examples of failures to do single     the race-for-fish is replaced by some form of tenure,
species management properly, since the stocks were     representatives of fishing groups will become an inter-
generally fished down to less than 1% of their original   est group with a high vested interest in making deci-
biomass — far below single species guidelines of 25 to   sions that will allow for the long-term sustained use of
50%. Sea otter, great whales and bluefin tuna were     the resource. With appropriate incentives, commercial
largely unregulated and highly valuable. The natural    fishing groups have often called for lower catches,
outcome was to move to the bio-economic equilibrium     have engaged in data collection and analysis, and have
which is near extinction. For these stocks, single     often even funded the majority of the scientific advis-
species management did not fail, it wasn’t practiced.    ing process.
In northern cod, the scientific/political system failed    Ecosystem management of fish and fleets. The
(Harris 1998). While ecosystem changes may have       important elements in incentive-based ecosystem
resulted from the severe depletion of these stocks,     management are fishing fleets and fish, rather than
these changes would likely not have happened had the    fish and their ecosystem. The dynamics of investment,
stocks been maintained at the abundances called for     fish harvesting, markets, and the incentives for fisher-
under conventional single species management. Thus,     men to conserve fish are, the most important con-
this list of fisheries failures suggests that the problem  siderations for sustainability. The trophic interactions
was poor implementation of single species manage-      between species, the dynamics of marine ecosystems,
ment rather than a need to move beyond it.         or the scientific approach applied in determining quota
  MSY. MSY emerged in the 1950s as the default       recommendations are secondary considerations. Fol-
management objective within fisheries science. How-     lowing from this, ecosystem management should have
ever, by the mid-1970s it had been largely discredited   the following characteristics: (1) incentives in the form
among scientists who recognized that maximizing the     of marine tenure will be in place so that the long-term
tons of fish landed was unlikely to be the appropriate   economic and social benefits of all participants will be
goal of fisheries management (Larkin 1977). Yet, be-    maximized by sustainable fishing practices; (2) data
278                    Mar Ecol Prog Ser 274: 269–303, 2004




collection, analysis, setting regulations, and enforce-    this is very expensive, it may well be the true real cost
ment, will be on the spatial scale appropriate to the     of achieving economically sustainable fisheries that
biology of the fish and the structure of the fishing com-   meet society’s goal to protect biodiversity. Alternatives
munities; (3) stakeholders will be intensively involved    might include expanding protected areas as reserves
in all levels of science, management and enforcement,     for by-catch species that would then be unprotected in
and under some circumstances fishing groups will       the exploited areas. Incentives have an important role
have complete control over the resource; (4) all costs of   to play because the higher the market value of a spe-
research, management and enforcement will be paid       cific form of tenure is, the more important it is to the
by user groups; (5) the primary role of central govern-    tenure holder not to have the tenure revoked due to
ments will be to audit the system to assure that the     violation of regulations.
biology and economics of the fishery are sustained and      By offering user groups marine tenure that gives
to ensure that national/international agreements and     them much more direct control of their own destiny,
laws are respected and enforced; and (6) substantial     and of a highly valuable asset, governments have been
portions of the marine ecosystem will be protected      able to obtain agreements with fishing groups to
from fishing activity to provide biodiversity reserves    accept and maintain industry funding of the costs
and reference sites (in the sense of an unexploited      of fisheries research and management (Australia,
control group).                        New Zealand, Iceland, Chile) as well as intrusive and
  The Pew Oceans Commission identified governance      expensive observer coverage. I am not advocating
structure as the key failing in U.S. fisheries policy (Pew  ITQs, and the usual allocation based on catch histories,
Oceans Commission 2003), and recognized the need to      as the primary form of tenure. There are many other
separate allocation from conservation decisions. How-     forms of tenure that would achieve the desired goals,
ever, this commission did not see a significant role for   among them state ownership with high access fees and
incentives. Rather, it recommended strong, centralized,    cooperatives. However, to achieve a politically viable
top-down control. The top-down approach contrasts       transition from our current system to a tenure system
with the incentives approach in that the former often     something has to be offered to the fishermen. The
views the exploiters of marine resources as natural      obvious solution is a significant portion of the future
destroyers of marine environments who need to be       catching rights in the form of ITQs, with the remainder
excluded from decision making as much as possible,      owned and leased by the state.
while the latter views them as necessary partners in       Summary. Ecosystem management means different
achieving good management.                  things to different authors. I present here my vision of
  Where economic incentives are not enough. The       the key elements of such an approach. The emphasis
strict economic incentives associated with marine       on institutions and the evolution of current single spe-
tenure will not protect all ecosystem components from     cies management approaches is consistent with many
the effects of fishing. For example the following topics   others, but differs greatly from the ‘revolutionary’
would still need to be addressed: (1) unproductive      change called for in response to the perceived failure
species in mixed species fisheries; (2) by-catch of      of single species management. I see the failures of fish-
threatened or endangered species; (3) trophic impacts     eries management as being due to a failure to recog-
of fishing; (4) habitat impacts of fishing; (5) long-lived  nize the importance of people and people manage-
species where the economic optimum is depletion; and     ment, not due to single species management. I support
(6) where international jurisdictions makes granting     the view of ecosystem management that recognizes
tenure difficult or impossible. The economic return to    the institutional dynamics between harvesters, man-
tenure holders is not increased by avoiding these prob-    agers and scientists, and stops the race-for-fish and
lems and here I see governmental agencies having an      overcapitalization through incentives rather than stop-
important auditing role. Consider a theoretical exam-     ping overfishing through centralized top-down con-
ple in which some group had been granted ownership      trol. I share with the papers of the Litany a common
and management rights to fishing grounds. The tenure     vision of the world’s fisheries that have smaller fishing
holder should be required to develop a management       fleets, higher stock biomasses and significant areas
plan associated with the areas of concern listed above,    protected from fishing. However, I see a very different
that would include monitoring, evaluation and en-       way to achieve these goals. In my vision incentives are
forcement. The management plan might involve         key, fishermen are involved in all aspects of manage-
mandatory by-catch quotas, gear modifications to       ment, and they also pay for the annual costs of fisheries
avoid non-target species, prohibition of destructive     management.
fishing gears, or overall catch quotas on some non-      Acknowledgements. I thank Doug Butterworth, Serge Garcia,
target species. For many fisheries, this may require     Loo Botsford, Dan Huppert, J. J. Maguire and Kevin Stokes
intensive, perhaps complete, observer coverage. While     for comments on the manuscript.
                                                           279
           Theme Section: Ecosystem-based approaches to management of marine resources




The ecosystem approach to fishery              with wider commitments to sustainable development.
                               Indeed, while many commentators are still asking for
management: a significant step towards
                               fishing impacts to be considered in environmental
  sustainable use of the marine
                               policy, the requirements to protect ecosystems from
      environment?                   the wider impacts of fishing, and to adopt an ecosys-
                               tem approach, have already been written into most of
          Simon Jennings
                               the key policy documents relating to marine environ-
Centre for Environment, Fisheries and Aquaculture Science,
                               mental management (Sainsbury & Sumaila 2003, Rice
      Lowestoft Laboratory, NR33 0HT, UK
                               2004). The ecosystem approach, as described in exist-
        Email: s.jennings@cefas.co.uk
                               ing policy documents (e.g. WSSD 2002), contributes
                               to sustainable development, which requires that the
  Environmental managers regulate human activities      needs of future generations are not compromised by
to improve ecological, social or economic sustainabil-    the actions of people today. The ecosystem approach is
ity. Such regulation is not always effective, and most    variously defined, but principally puts emphasis on a
fisheries are seen as excellent examples of failed      management regime that maintains the health of the
natural resource management. While regulation and       ecosystem alongside appropriate human use of the
societal pressure have often led to reductions in the     marine environment, for the benefit of current and
environmental impacts of shipping, aggregate dredg-      future generations.
ing, waste disposal and the oil and gas industries, fish-    EAF is part of the ecosystem approach. The broad
ing is widely seen as the remaining pariah, currently     purpose of the EAF is to plan, develop and manage
attracting the attention of the global media and numer-    fisheries in a manner that addresses the multiple needs
ous conservation and lobby groups.              and desires of societies, without jeopardising the
  Today, most fisheries are managed on a stock-by-      options for future generations to benefit from the full
stock basis. Reference points are established for stock    range of goods and services (including, of course, non
biomass and fishing mortality and then catch controls,    fisheries benefits) provided by marine ecosystems
effort controls or technical measures, such as changes    (FAO 2003). The success of an ecosystem approach will
in mesh size or area closures, are recommended to       depend on whether these high level and somewhat
managers to modify mortality rates. In reality, man-     abstract commitments can be turned into specific,
agers have always struggled to reduce fishing mortal-     tractable and effective management actions (Sains-
ity, and the biomass of many stocks is below intended     bury et al. 2000, Sainsbury & Sumaila 2003).
reference points (FAO 2002a). The failures of manage-      To assess the potential of the ecosystem approach,
ment are catalogued in numerous publications and the     we need to ask whether it will nullify the failings of
principal ecological, social and economic reasons for     existing approaches and change attitudes to use of the
failure are well understood (OECD 1997, FAO 2002b).      marine environment. From ecological, economic and
This understanding has thus far done little to improve    social perspectives, existing management methods
the overall effectiveness of management in ecological,    have generally failed. Thus, 47% of the world’s main
social or economic terms.                   stocks or species groups are fully exploited, while 18%
  Although the depletion or collapse of target stocks is   are overexploited and 10% are severely depleted or
often the most visible and well-publicised failure of the   recovering from depletion. Only 25% of stocks are
fisheries management process, fisheries take place in     under- or moderately exploited (FAO 2002a). The FAO
ecosystems and have wide ranging ecological impacts.     conducted one of the most comprehensive analyses of
These impacts have become an increasing focus of       the factors contributing to unsustainability in fisheries
research effort, as evidenced by recent symposia       (FAO 2002b). These were inappropriate incentives and
(Gislason & Sinclair 2000, Kaiser & de Groot 2000,      market distortions, high demand for limited resources,
Sinclair & Valdimarsson 2003) and reviews (Gislason      poverty and lack of alternatives to fishing, complexity
1994, Dayton et al. 1995, Jennings & Polunin 1996,      and inadequate knowledge, lack of governance, and
Jennings & Kaiser 1998, Hall 1999, NRC 2002). This      interactions of the fishery sector with other sectors and
interest in fisheries ecosystem interactions is not new    the environment (FAO 2002b). Their analyses showed
(e.g. Anderson & Ursin 1977, Pope 1979, Pope et al.      that scientific advice on the status of fish stocks and the
1988) but the recent shift in research effort from single   effects of fishing made only a small contribution to a
species to ecosystem-based concerns reflects the       complex management and decision-making process,
growing recognition that an ecosystem approach may      and often carried little weight in relation to immediate
help to underpin improved management.             social and economic considerations. Advice on fish-
  From a policy perspective, the move towards an       eries exploitation in an ecosystem context will also
ecosystem approach has been rapid and is consistent      make a small contribution to a larger process that is
280                   Mar Ecol Prog Ser 274: 269–303, 2004




influenced by many of the same social and economic      instruments that capture at a private level the social
factors. Thus, scientific advice may carry little weight   and global values of relatively undisturbed ecosystems
when there are very high short-term social and eco-     through, for example, premium pricing for fish caught
nomic costs associated with moving towards sustain-     from healthy ecosystems (Phillips et al. 2003), may help
ability. These costs are common to both single species    to increase the short-term benefits associated with
and ecosystem-based approaches (Rice 2004). The       conservation. However, such instruments will not pro-
ecosystem approach will not remove the very high       mote conservation in many areas where unsustainable
short-term costs of protecting the environment unless    fisheries provide the main source of food, income and
incentives are introduced to link conservation and      employment. This requires a willingness of Govern-
short-term financial reward.                 ments to commit substantial international funding, but
  From an ecological perspective, the ecosystem ap-     the gap between commitment and available funding
proach recognises, and aims to remedy, the unwanted     is large and growing (UNDP 2003).
impacts of fishing on non-target species, habitats and     Scientific research has shown that the sea provides
ecological interactions. The approach recognises that    essential ecosystem goods and services with high long-
ecosystems provide goods and services other than fish    term value (Balmford et al. 2002), yet human impacts
and may change the burden of proof if existing man-     on the sea are rarely an important political issue in
agement is not precautionary (Sainsbury & Sumaila      comparison with health, poverty, education and mili-
2003). However, in the broadest directional terms,      tary disputes. Management of the marine environment
scientific advice is consistent from both single-species   is not a top spending priority for Governments because
and ecosystem perspectives: significant capacity re-     it does not have an immediate impact on most voters
ductions are needed. The most pervasive ecosystem      lives. Public attitudes, rather than new types of scien-
impacts are still the result of massive over capacity,    tific advice, are most likely to change this. In this
and scientific advisers on single-species issues have    respect, high profile and media friendly conservation
been arguing for capacity reductions and time or area    projects, such as those supported by the Pew Charita-
closures for decades. Managing fisheries in an ecosys-    ble Trusts, will have a significant role in changing pub-
tem context also leads to advice to reduce capacity and   lic perceptions, and may serve to increase the short-
implement time or area closures. True, there are cases    term political costs associated with the failure to move
where otherwise sustainable fisheries have additional    towards sustainability.
adverse effects on non-target species and habitats       The extent to which society can strengthen the case
(Witherell et al. 2000) but, at the present time, such    for management action was well demonstrated by the
fisheries are in the minority relative to those where    effects of consumer and conservation campaigns on
mortality has to be cut simply to ensure conservation of   attitudes to marine mammal bycatch. Indeed, pressure
target stocks. Indeed, the ICES Advisory Committee      on the US Government led to the implementation of
on Ecosystems concluded that managers would have       the Marine Mammal Protection Act in 1972. This
to deal with a much smaller and more tractable set of    required the adoption of fishing practices that reduced
ecosystem issues if capacity were reduced to the extent   dolphin bycatch and the presence of independent
that all target stocks were fished sustainably (ICES     observers on vessels to monitor and control bycatches
2001).                            (M. A. Hall 1998). By 1972, another bycatch species,
                               the common skate Dipturus batis, was effectively
  The preceding arguments suggest that the transition
from single-species to ecosystem-based approaches      extinct in the Irish Sea (Brander 1981). There was little
will not alter the high short-term social and economic    public interest in the common skate, and over 30 yr
costs of reducing capacity nor the general advice that    later no specific measures have been implemented to
capacity should be reduced. Thus, scientific advice on    protect this species (Dulvy et al. 2003). Clearly, the
the North Sea cod fishery that is framed in an eco-     influence of society on commitments to policy imple-
system context would not be more stringent than the     mentation has the potential to create ecosystems that
request for a zero catch in 2004 (ICES 2003a). Perhaps    are dominated by ‘favoured’ species. Although the
a more relevant issue is whether the adoption of the     ecosystem approach is intended to take account of
ecosystem approach will encourage society to exert      human impacts on the whole ecosystem, the first steps
more pressure on Governments to bear high short-       towards implementation may be remarkably piece-
term costs, and to translate high level political commit-  meal and have a range of unexpected consequences.
ments into capacity reductions and improvements in       Thus far, attempts to implement an ecosystem
the ecological status of the marine environment. Ulti-    approach have often been characterised by a polarised
mately, society’s willingness to bear these high short-   debate between ‘ecosystem’ and ‘stock assessment’
term costs, directly or indirectly, will determine the    scientists, and the unwillingness of some advocates of
success or failure of the ecosystem approach. Market     ecosystem based management to accept useful parts of
                                                        281
           Theme Section: Ecosystem-based approaches to management of marine resources




the existing management system. The most effective     the ecosystem approach is less likely to paralyse the
progress towards an ecosystem approach is likely to be   decision-making process and will help to maintain
achieved by moving forward collectively, integrating    broad based support.
the useful aspects of existing approaches into new       From a practical perspective, the essential diversity
ones. There are 2 reasons for this. First, both ecosys-   of scientific involvement in the ecosystem approach
tem- and stock-based approaches, at least at a global    can readily confuse managers. Thus fisheries man-
scale, lead to the same advice; to reduce fishing capac-  agers who once turned to stock assessments, now have
ity and restrict access. Second, it has taken a long time  to consider genetic and species diversity (Law 2000,
to improve understanding of the issues that affect the   Murawski 2000), species rarity (Casey & Myers 1998,
success of environmental management, such as deal-     Schindler et al. 2002), habitats (Collie et al. 2000,
ing with risk and uncertainty (Hilborn 1996, Harwood    Kaiser et al. 2002), food web properties (Pauly et al.
& Stokes 2003), and such insight should not be wasted.   1998, Cury et al. 2003) and the ecology of marine
The assumption that solutions are simple, but over-     mammals and birds (M. A. Hall 1998, Tasker et al.
looked or untested, has led to many false dawns in     2000) when managing the marine environment. Fish-
environmental management.                  ing has become an issue on which most ecologists have
  One such concern exists in relation to closed areas,   strong opinions, but the breadth of knowledge and
which are increasingly proposed as an almost singular    experience required to provide balanced and credible
solution to the adverse effects of fishing. While closed  advice that can actually be used by decision makers is
areas are an important management tool, and are       formidable (Sissenwine & Mace 2003). It will also be
frequently not used even when they could mitigate      difficult for managers to reconcile the range of advice
unsustainable fishing impacts (Sainsbury & Sumaila     they receive in the absence of established guidelines
2003), a single-minded focus on area closure as       on the implementation of an ecosystem approach;
opposed to capacity reduction and other measures is     though some management agencies have such guide-
unlikely to reduce significantly the aggregate impacts   lines (Constable et al. 2000, Witherell et al. 2000)
of fishing. Thus, increased use of closed areas without   and most others are working towards them (FAO 2003,
associated capacity reduction will displace fishing     Rice 2003).
impacts to places where fisheries regulations are not so    One component of the ecosystem approach that may
stringent, and to more vulnerable areas, such as parts   play an increasing role in shaping the future of marine
of the deep sea (Koslow et al. 2000). Progress towards   environmental management is the use of environmen-
effective ecosystem-based management will ulti-       tal impact assessment. Fisheries are effectively exempt
mately depend on both access restriction and effective   from the requirements for impact assessment, even in
capacity reduction. However, the increasing applica-    areas where other users of the marine environment,
tion of area closure in supporting aspects of ecosystem-  such as the oil and gas industries, would be required to
based management (e.g. protection of vulnerable habi-    conduct them. There is a precedent for a move towards
tats, genetic diversity or food web structure) will begin  environmental impact assessment in the FAO Code of
to play an important role in changing perceptions      Conduct for Responsible Fisheries (FAO 1995b), which
about open access to the marine environment.        suggests that conservation and management should be
  The ecosystem approach is sometimes seen as end-     cautious until sufficient data for assessment are avail-
lessly complicated, and it is a common misconception    able. Impact assessment would usefully deal with
that we need to understand the structure and function    social and economic as well as ecological factors, but
of entire ecosystems to implement effective ecosystem-   would need to incorporate an agreed long-term per-
based management. While understanding ecosystems      spective to reduce the significance of high short-term
is a worthy intellectual exercise, it can be an inappro-  costs. Moreover, the application of impact assessment
priate and unrealistic use of limited resources that    would require new management structures that facili-
could be used to address specific and tractable issues.   tated collaboration between marine ecologists, social
True, the science required to underpin the ecosystem    scientists, lawyers and economists, but did not paralyse
approach will be more diverse than that contributing to   the decision-making process.
fisheries stock assessment, but funding for this science    To conclude, the mechanisms to implement an eco-
cannot be expected to increase in proportion to the     system approach are increasingly well developed
range of ecosystem issues that scientists will be asked   and such an approach will improve sustainability in
to address. The most significant and cost-effective     wealthier nations, provided that society is strongly
progress towards the ecosystem approach is most       supportive. With support from society, management
likely to be made by appropriate reorientation of exist-  methods would be expected to evolve quite rapidly
ing science and management tools. An emphasis on an     until fisheries are treated on a par with other sectoral
evolutionary rather than revolutionary move towards     activities that impact the marine environment. It is
282                     Mar Ecol Prog Ser 274: 269–303, 2004




expected that the capacity of fishing fleets will be       trophic level species faces limits. Single-species man-
much reduced, there will be fewer subsidies, new fish-      agement approaches aiming for maximizing resource
eries will only be licensed following impact assessment     output to humans have often failed to prevent deple-
and habitat and species conservation issues will         tion and collapse. Multiple human impacts that destroy
become an increasing focus of management plans.         habitat and environmental quality essential to the sus-
Indeed, the work of the North Pacific Fishery Manage-      tenance of aquatic species need to be considered. If
ment Council suggests that the ecosystem approach        ‘ecosystem-level’ management is used just as a new
can be implemented effectively when there is suffi-       label hiding the continuation of ongoing practices and
cient commitment (Witherell et al. 2000). In many        attitudes, we will drive aquatic resources to further
poorer nations, prospects for improved sustainability      depletions, collapses and extinctions, possibly passing
are not good, unless the international community         the point where recovery would still be possible. There
commits to supporting and financing the ecosystem ap-      is an alternative. Ecosystem-level management should
proach and subsidising the very high short-term social      aim for managing ecosystems with the goal of optimal
and economic costs associated with reducing capacity.      functioning of all parts, including ourselves. This
                                 requires a shift in perspective. We are faced with the
Acknowledgements. Many thanks to Colin Bannister, Nick
                                 challenging opportunity to break our historical patterns.
Dulvy, Joe Horwood, Jake Rice and the editors of this TS for
                                  Repetitive history of resource use and management.
helpful comments on the text. Their generosity in reading the
                                 Apparent inexhaustibility of unexploited resources:
text does not necessarily mean that they all agree with my
opinions!                            Whenever people in the past encountered oceanic
                                 regions that were formerly not or only little exploited,
                                 the vast richness of large fish, birds, turtles, whales,
Repetitive history of resource depletion             and other marine animals astonished them. Whether
                                 people visiting the Baltic or North Sea 1000 yr ago
 and mismanagement: the need for a
                                 (Hoffmann 2001, 2002), or Europeans reaching the
     shift in perspective
                                 New World 500 yr ago (e.g. Cabot 1497/98 cited in
           Heike K. Lotze               Hoffmann 2001, Rosier 1605 cited in Steneck 1997),
                                 their descriptions are similar. The newly discovered
Wattenmeerstation Sylt, Alfred Wegener Institute for Polar and
                                 seas and the bounty of life always seemed inex-
  Marine Research, Hafenstrasse 43, 25992 List, Germany
                                 haustible. Even in the 19th and 20th century, people
Present address: Leibniz Institute for Marine Science, Experi-
                                 continued to believe in this myth of inexhaustibility
mental Ecology, Düsternbrooker Weg 20, 24105 Kiel, Germany
        Email: hlotze@ifm-geomar.de           (Hutchings & Myers 1995, Pauly et al. 2003). Through-
                                 out our history, we have repeatedly proven ourselves
  History tends to repeat itself. Plentiful resources      wrong.
                                  Human population density and demand: Prehistoric
always impressed humans as being inexhaustible. We
exploited them without thinking much about eco-         people hunted, fished and gathered to sustain them-
logical consequences and replenishment. Only when        selves or to trade with neighbors. Archaeological evi-
resources declined did we start to implement manage-       dence suggests that in regions with low population
ment actions such as privatization, quotas, closed        density indigenous people had no or little impact on
seasons and other restrictions. High human demand as       common target species such as marine mammals,
well as economic, social or political pressures, how-      birds, fish and shellfish (Steneck 1997, Lotze & Milew-
ever, often undermined sufficient management prac-        ski 2004). In contrast, in regions with high human
tices leading to overexploitation and collapse. Unfortu-     population density, most valued species declined in
nately, human societies usually did not question their      relative abundance, size or distribution over time,
actions or demands when resources collapsed, but         indicating high exploitation pressure (Broughton 1997,
moved on to either (1) exploiting the same species        Smith 2004). Thus, in some hunter-gatherer societies
somewhere else, (2) exploiting a less preferred species     human population density and demand was already
locally, or (3) intensifying local resource production      high enough to cause severe resource depletion.
through aquaculture. Today, these ‘solutions’ are still       Since then, human population has grown exponen-
widely used, but hardly work anymore. We have          tially and demands have multiplied, not only for food,
reached global limits of exploitation at the poles, the     but increasingly for profit, fashion, and prestige. For
open ocean and the deep sea. We have successively        example, rare sturgeon or salmon were reserved for
depleted lakes, rivers, coastal seas, and finally the      kings and the elite in the late Middle Ages (Hoffmann
open ocean, leaving many species overexploited,         2001), whales were hunted for their baleens, which
endangered or extinct. Although a potential solution to     were used in ladies’ fashion, and seabirds were killed
substitute for depleted stocks, aquaculture of high       in the millions to supply the millinery trade in the 19th
                                                             283
           Theme Section: Ecosystem-based approaches to management of marine resources




century (Lotze & Milewski 2004). Excessive exploita-     with formerly unexploited species that were less val-
tion has resulted in rapid depletion and extinctions     ued, smaller, harder to catch, or lower in the food web
since the Middle Ages, and especially in the 19th cen-    is the third common management practice (Fig. 1).
tury (Hoffmann 2002, Lotze & Milewski 2004). Fishers,    Today, low-trophic level exploitation of crustaceans,
hunters, traders and entire nations increasingly com-    mollusks and marine plants dominate most coastal
peted in the rush for valued but dwindling resources     fisheries (Pauly et al. 2002, Lotze & Milewski 2004).
(Hoffmann 2002).                       The fourth form of management practice is intensifica-
  Shifting values and subsequent conservation efforts    tion of local production. Like fishing, aquaculture
in the 20th century led to the recovery of some species   moved from freshwater to anadromous to marine
(Murawski et al. 2000, Cloern 2001, Lotze & Milewski     fishes. Aquaculture of introduced carp was invented in
2004). Today, ocean wildlife is exploited to meet the    the Middle Ages (Hoffmann 2002), that of salmon in
food demands of an ever-increasing human popula-       the 1970s, and today farming of marine groundfish
tion, as well as to supply global luxury markets. This    such as cod or haddock is becoming a reality. In con-
growing demand, however, is restrained by an         trast to herbivorous carp, however, aquaculture of pis-
increase in the number of collapsed or overexploited     civorous fish faces limits and creates many environ-
fish stocks, and declining global catches (Botsford et al.  mental problems (Pauly et al. 2002).
1997, Pauly et al. 2002, Myers & Worm 2003, 2004).       Whether it is privatization and regulation, expan-
While human population growth in the Middle Ages       sion, substitution, or intensification, we still repeat
was mainly fuelled by the supply of cereals (Hoff-      historical patterns, albeit on a global scale (Botsford et
mann 2001), today’s population demands a continuous     al. 1997, Pauly et al. 2003). Today, depleted aquatic
supply of fish and meat. Clearly, as a society, we need   resources are the rule rather than the exception. Large,
to adapt our demands to the capacity of marine eco-     long-lived species such as northern right and hump-
systems, not vice versa.                   back whale, great auk and Labrador duck, sturgeon
  Resource depletion and management: Throughout       and salmon, haddock and cod, sharks and rays are
history, humans have reacted to local resource deple-    extinct or rare, i.e. at around 1 to 10% of their former
tion by implementing management actions that be-
longed to 4 major categories: (1) privatization and
regulation, (2) expansion to unexploited regions, (3)
substitution of depleted target species with less
exploited species, and (4) intensification of local pro-
duction through aquaculture.
  In the Middle Ages, human population density
increased markedly throughout Europe and the first
signs of depletion of preferred aquatic food sources
such as sturgeon and salmon were already evident in
the 13th century (Hoffmann 2001). Privatization and
regulation with quotas, gear, seasonal and other rest-
rictions were implemented by landowners or territorial
authorities (Hoffmann 2002). However, in the Middle
Ages, as well as today, these management practices
were often overridden by socio-economic pressures
(Botsford et al. 1997). Therefore, a continued decline in
resources led to the expansion of frontiers to formerly
unexploited regions. Fisheries moved from freshwater
to marine environments in medieval Europe (Hoff-
mann 2001, 2002), from inshore to offshore in the
North Sea and North Atlantic beginning in the 1400s
(Hutchings & Myers 1995, Steneck 1997, Hoffmann
2002, Lotze & Milewski 2004), and to the open ocean,     Fig. 1. Substitution of depleted resources in the Outer Bay
polar and deep seas in the 19th and 20th century       of Fundy, NW Atlantic. (A) Declining catches of traditional
                               groundfish (cod, haddock, pollock; dotted line) led to increasing
(Pauly et al. 2002, 2003, Myers & Worm 2003). The
                               invertebrate and plant landings (solid line). Note that high
history of whaling shows a similar pattern of spatial
                               groundfish landings in the 1960s arose from expanding to
expansion from coastal to offshore and polar regions,    offshore fishing grounds and the introduction of otter trawls.
as well as serial depletion of one species after another.  (B) Increase in the number of target species in commercial
This successive substitution of depleted target species   fisheries over time. Data adapted from Lotze & Milewski (2004)
284                   Mar Ecol Prog Ser 274: 269–303, 2004




abundance (Myers & Worm 2003, 2004, Roman &         and noise. These ‘side-in’ impacts reduce overall avail-
Palumbi 2003, Lotze & Milewski 2004). Traditional      ability of high quality habitat and environment, and
management approaches have failed to ensure sus-       the amount of undisturbed space and time (Lotze &
tainable use of aquatic resources (Botsford et al. 1997,   Milewski 2004).
Pauly et al. 2002), and extrapolation of present trends     The cumulative effects of top-down, bottom-up and
into the future presents us with a grim picture (Pauly et  side-in impacts can alter species interactions, acceler-
al. 2003). If aquatic wildlife and ecosystems as well as   ate species declines and impair recovery (Lotze &
fisheries productivity is to be sustained, our society    Milewski 2004). In medieval Europe, deforestation,
needs to shift to more sustainable management and      agricultural expansion, river damming, water pollu-
question its demands.                    tion, and nutrient loading had already affected
                               freshwater fishes in addition to direct exploitation
  Ecosystem management as a shift in perspective.
Towards an ecosystem perspective: For a long time,      (Hoffmann 2001, 2002). Recovery of Atlantic salmon
the goal of single-species management was to manage     was for a long time impaired by river pollution and
populations for maximum possible output for humans.     destruction of spawning habitats (Lotze & Milewski
If ecosystem-level management is used in the same      2004). Starting in the rivers, multiple human impacts
sense, it will surely only accelerate present patterns of  also spread into estuaries and coastal seas, possibly
depletion and degradation. Ecosystem-level manage-      impairing recovery of collapsed groundfish stocks
ment should mean that ecosystems are managed with      (Lotze & Milewski 2004). With climate change and
the goal of optimal functioning of all parts including    worldwide fishing, humans today affect the oceans on
ourselves. This requires that (1) all the parts (species,  a global scale. Former human civilizations collapsed
habitats) are kept, (2) all parts are kept in a state (of  not only because of food shortage but also because of
abundance, diversity, complexity) that allows long-     the indirect effects of exploitation such as water and
term persistence and resilience of populations, com-     fuel shortage (Hughes 2001). Today, our society has
munities and ecosystems, and (3) high environmental     the advantage of knowing what we are doing, and the
quality is provided to ensure health and survival. It    option of acting upon that knowledge.
                                Ecosystem-level versus human-impact management:
also requires integrating multiple human impacts
into an ecosystem framework because humans inter-      Managing an entire ecosystem will be a difficult task
fere with all parts through the cumulative effects of    because of our limited understanding of all its parts
exploitation, habitat destruction, nutrient loading, pol-  and the linkages between them. In many cases,
lution, and other disturbances. Diverse, productive and   however, we have a reasonably good understanding
functioning ecosystems will not only conserve aquatic    of human impacts and should, therefore, focus on
wildlife and wilderness, but will also likely enhance    ‘human-impact’ management in order to reduce our
productivity, water quality, economic options and other   negative and enhance our positive influences. In
goods and services for human societies.           addition, marine protected areas (no-take zones) are
  Integrating multiple human impacts: Humans have      needed as controls to measure change against, as
multiple impacts on aquatic ecosystems that interact     insurance against management failures, to preserve
with one another and must, therefore, be managed       diversity, and to ensure the persistence and resilience
together. Historically, direct exploitation was the first  of aquatic ecosystems (Palumbi 2001, Worm et al. 2003).
human impact on aquatic resources. In a food web con-      Human-impact management should include techni-
text, humans act as top-predators having ‘top-down’     cal improvements to minimize negative impacts, pro-
impacts which have increased multi-fold from early      tection and restoration of species and habitats, and the
subsistence cultures to today’s societies (Lotze &      reduction of our demand as feasible management
Milewski 2004). These direct impacts on populations     options. ‘Top-down’ impacts can be reduced by effort
are complicated by indirect community effects such as    control through quotas and cutback on subsidies, which
depensation and trophic cascades. Moreover, human      will help to re-balance size of fish stocks and fishing
activities also affect the food web from the ‘bottom-up’   fleets (Botsford et al. 1997, Pauly et al. 2002). Protected
through resource enhancement such as nutrient load-     areas reduce the spatial extent of exploitation and pro-
ing (Cloern 2001, Lotze & Milewski 2004). These bot-     tect threatened diversity (Worm et al. 2003). Technical
tom-up impacts interact with top-down impacts.        improvements of more selective and less destructive
Reduction of consumers and enhancement of nutrient      gear types reduce bycatch and habitat destruction.
loads, for example, can result in excessive algal      ‘Bottom-up’ impacts can be reduced by wastewater
blooms, loss of diversity and ecosystem functions      treatments at point sources, while restoration of wet-
(Worm et al. 2002). Each trophic level is further      lands as natural buffer and filters will reduce non-point
affected by pollution effects on health, habitat destruc-  pollution (Cloern 2001). Reduction of ‘side-in’ impacts
tion, and increasing stress due to disturbance, traffic   requires technical improvements to reduce chemical
                                                          285
           Theme Section: Ecosystem-based approaches to management of marine resources




pollution, noise stress, and destructive harvesting prac-   major public issue. The frequency of such publications
tices, in addition to protected areas that allow habitat   has increased dramatically in the last decade. While
regeneration and species recovery (Murawski et al.      few would dispute the existence and importance of
2000, Palumbi 2001). Technical improvement of aqua-      overfishing in many of the world’s fisheries, there are
culture can reduce discharges of chemicals, pharma-      numerous arguments about the severity of the situa-
ceutics, and wastes into the environment.           tion, its reversibility, the causes and, particularly, the
  Reducing excessive and destructive exploitation and    solutions. I believe that the current perception of the
enhancing habitat availability and environmental       status of marine species and ecosystems is overly
health were successful measures for recovery of some     alarmist; at best unhelpful and at worst destructive.
birds, mammals, fish and invertebrates in the 20th      Many scientific papers have exaggerated the severity
century (Murawski et al. 2000, Cloern 2001, Lotze &      and apparent hopelessness of the situation, inappro-
Milewski 2004). It is the role of scientists to explore,   priate scapegoats have been blamed, success stories
test, communicate, and insist on implementation of the    have largely been ignored, and either overly simplistic
best management options. It is the role of society to     ’solutions’ (e.g. MPAs, by themselves) or complex,
take responsibility for its impacts and act upon the best   non-operational ’solutions’ (e.g. convoluted systems of
available knowledge.                     ecosystem indicators) have frequently been proposed.
  Chance and challenge. Throughout history, the       In particular, single-species approaches have been
ocean was seen as the last frontier, the last wilderness   condemned, and there has been a call to replace them
untouched by human activities. This is not true any-     with often ill-defined ’ecosystem approaches’. These
more (Bostford et al. 1997, Pauly et al. 2002, Myers &    are the main themes on which I elaborate here.
Worm 2003, 2004), and it hasn’t been true for centuries     The actual situation. World landings of marine spe-
(Hoffmann 2001, 2002, Jackson et al. 2001, Lotze &      cies (excluding plants) are currently about 70 to 80 mil-
Milewski 2004). Exploitation, habitat destruction, pol-    lion metric tonnes (t) depending on the statistics used
lution, eutrophication, invasions, and climate change     for China, which is believed to have over-reported
have altered the seas rapidly and on a global scale. It    catches, particularly since the early 1990s (FAO 2002a).
should come as a warning, that former civilizations      Marine aquaculture adds another 10 to 15 million t,
missed the point of return and collapsed because of the    with the same uncertainty about Chinese statistics.
unforeseen direct and indirect effects of exploitation    Because of these and other uncertainties, there is con-
and habitat destruction (Hughes 2001). In contrast to     siderable debate about recent and projected trends in
them, and indeed for the first time in history, our soci-   landings. Marine aquaculture production is certainly
ety is in a position to understand where we are. This is   increasing, but global landings of wild marine species
a unique chance and challenge to break our historical     could be more or less stable, or somewhat declining
patterns. Because of our global impacts, it might be our   (FAO 2002a, Watson & Pauly 2001b). FAO (www.fao.org)
only one.                           projects that landings from marine capture fisheries
                               will be in the range of 80 to 105 million t in 2010. Oth-
Acknowledgements. Many of the ideas expressed in this     ers (e.g. Pauly et al. 2003) have presented much more
paper resulted from discussions with Boris Worm. I acknowl-
                               pessimistic scenarios. Regarding the current situation,
edge support by the History of Marine Animal Populations
                               FAO (2002a) estimates that, of the major marine fish
(HMAP) program, funded by the Sloan foundation.
                               stocks or species groups for which information is avail-
                               able, 10% are depleted or recovering from depletion,
In defence of fisheries scientists, single-          another 18% are overexploited, 47% are fully ex-
                               ploited, and 25% are underexploited or moderately
species models and other scapegoats:
                               exploited, i.e. only 28% are overexploited or depleted.
   confronting the real problems
                               Globally, the most pressing concerns are the continued
          Pamela M. Mace*              overexploitation of many major marine species and the
                               extent of depletion of both target and associated spe-
Ministry of Fisheries, PO Box 1020, Wellington, New Zealand
                               cies, together with concomitant effects on community
        Email: pamela.mace@fish.govt.nz
                               structure and ecosystem function.
                                 Scapegoats. Fisheries scientists, single-species mod-
  The current perception of the status of marine spe-
cies. Articles decrying the negative impacts of over-     els, and the concept of Maximum Sustainable Yield
fishing have been written for more than 5 decades, but    (MSY) are 3 targets that are commonly, but unde-
it is only relatively recently that this has become a     servedly, singled out as being responsible for the
                               current situation.
                                 Fisheries scientists: In a recent news feature in
*The views expressed here are those of the author only and
                               Nature (Schiermeier 2002), the headline claimed that
do not reflect agency policy or opinion
286                    Mar Ecol Prog Ser 274: 269–303, 2004




’Commercial fisheries worldwide are being driven to      ward, and operational. Even by itself, successful
collapse. Quinn Schiermeier wonders why fisheries       single-species management is likely to go a long way
scientists are failing to halt this pillage, and asks what   towards achieving many so-called ‘ecosystem objec-
hope is there for the future sustainability of fish stocks.’  tives’ (NRC 1999b, Mace 2001). For example, bringing
Admittedly, this strong and inflammatory statement       high fishing mortalities on target stocks under control
was not reiterated in the text of the paper, and proba-    is also likely to result in reductions in fishing mortality
bly represents editorial licence designed to draw atten-    on associated and by-catch species, an overall
tion to the paper. However, the news feature does go      decrease in fishing fleet capacity and fishing effort,
on to claim that, ’At best, [fisheries scientists’] models   and concomitant reductions in adverse effects on
of the dynamics of fish populations produce imprecise     marine habitats.
                                 MSY: MSY has been condemned for various reasons,
estimates of the maximum catches that can be taken
without driving a stock to extinction,’ … ’At worst, the    including the belief that it is not sustainable (which it
models can incorporate misleading data that simply       must be, by definition; otherwise it has been incor-
give the wrong answer, causing scientists to help       rectly estimated). In fact, sustainability by itself is a
speed fisheries towards collapse,’ ... ’Given such fail-    very weak criterion for judging success. Fisheries on
ures, some conservation biologists are now arguing       extremely depleted stocks can, and have, been sus-
that fisheries scientists must abandon their focus on     tained over very long periods of time, resulting in con-
individual stocks and adopt a whole ecosystem per-       siderable foregone yields and high risks of stock col-
                                lapse. In order to achieve the maximum sustainable
spective.’
  In fact, fisheries scientists are usually tasked with    yield, it is also necessary to maintain high stock bio-
estimating optimal fishing mortality rates, not maxi-     mass. MSY (and its proxies) is one of the most readily
mum possible rates, and it is rare that stock assess-     understood and operational concepts that have been
ments themselves are so optimistic that they contribute    developed by fisheries scientists. Again, the major
to a fishery collapse. The more common situation is      problem is not that the concept is flawed, but that it has
that results produced by assessment scientists are dis-    rarely been treated seriously as a fishing target and is
credited by some segments of the fishing industry       therefore routinely exceeded, often substantially. For
if they indicate the need for reductions in fishing      this reason, and because additional consideration of
mortality, because this generally means reductions in     ecosystem effects of fishing will likely require even
catches and fishing incomes in the short term. What      more conservative fishing mortalities, the single-
is usually lacking is the political will to implement     species fishing mortality associated with MSY (FMSY) is
restrictive management measures (Mace 1997, 2001).       now commonly advocated as an upper limit on fishing,
  Single-species models: The much reiterated claim      rather than a fishing target (United Nations 1995,
that single-species fisheries assessment models have      Mace 2001). At the least, reducing fishing mortalities
failed and need to be supplanted with ecosystem mod-      on target species to or below the single-species FMSY
els distorts the facts. There are actually few examples    will likely be a major step towards restoring depleted
worldwide of fisheries that have been managed for any     species and ecosystems.
substantial period of time (e.g. a decade or more) at       The actual situation in perspective. There is no
fishing mortality levels at or below fisheries scientists’   doubt that overfishing exists in many of the world’s
estimates of single-species optimal levels.          fisheries and that, where it does exist, it needs to be
  Given the record of fisheries management to date, it    corrected. There is also no doubt that many major fish
is difficult to understand the reasoning that leads to the   stocks are depleted and in need of rebuilding in order
conclusion that ecosystem-based approaches will suc-      to increase sustainable yields and decrease the risk of
ceed where single-species approaches have failed. If      collapse to the stocks themselves, the ecosystems of
one of the major failings of single-species management     which they are a part, and the fisheries that depend on
has been the lack of political will to curtail allowable    them. It is the rapidity of the declines of marine spe-
catches, what is the basis for thinking that there       cies that many people find alarming. Although some
will be greater political will to implement probably-     coastal systems and individual fish stocks have been
even-more restrictive limits on catches, in addition to    exploited for centuries, it is only since about 1950 that
other management measures? Conservationists who        open ocean fishing and global landings both began to
advocate throwing out single-species models and        escalate. Compared to most terrestrial species, the
single-species management ‘because they haven’t        time horizon over which most marine species have
worked’ may be defeating the common objective of        declined appreciably is relatively short. However, a far
restoring depleted stocks and ecosystems. Unlike most     more important difference between marine and terres-
ecosystem objectives, the goals of single-species man-     trial systems is that the magnitude of declines in most
agement are usually easily understood, straightfor-      marine species pales in comparison to the situation for
                                                          287
           Theme Section: Ecosystem-based approaches to management of marine resources




most terrestrial species. Noss et al. (1995) summarize    remaining are probably still well above levels at which
estimates of the extent of decline of hundreds of ter-    risk of extinction is likely to become a concern.
restrial habitats in the United States and the rest of the    None of the above is meant to justify or dismiss high
world, citing dozens of examples where 95 to 99% of      levels of depletion of marine species. Rather, the intent
various habitats have been lost over huge areas, but     is to inject a note of optimism into the current, mostly
often over centuries rather than decades. Although      pessimistic, debate. While few wild terrestrial species
some authors, such as Myers & Worm (2003), claim that     can still be exploited sustainably, the situation for
there have been large-scale reductions of the order of    marine species is much more positive. And, despite
80 to 90% for many marine communities, the analyses      assertions to the contrary, there is strong evidence that
leading to these conclusions have been disputed by      it is not too late to reverse recent trends.
others (Walters 2003, Hilborn 2004 in this TS). Declines     Effects of reducing single-species fishing mortalities.
of the order of 50 to 70% are much more common and,      One of the most destructive aspects of the alarmists’
although such levels are likely to affect ecosystem      portrayal of the current state of marine fisheries is the
structure and function, they are hardly indicative of     perception that marine systems are heading towards
impending doom, especially since some amount of        inevitable collapse, if not extinctions on a massive
reduction in biomass is an inevitable consequence of     scale, and that it may be too late to do much about it.
harvesting a species. Down to a limit (usually assumed    For example, Hutchings (2000) claimed that ‘there is
to be 30 to 50% of the unexploited level), reductions     very little evidence for rapid recovery from prolonged
in biomass result in increases in the productivity of     declines, in contrast to the perception that marine
species by shifting the age distribution to younger,     fishes are highly resilient to large population reduc-
faster growing individuals, and possibly by reducing     tions’, and that most marine fish stocks ‘have experi-
competition for food and space.                enced little, if any, recovery as much as 15 years after
  The problem of ‘shifting baselines’ (not looking suffi-  45 to 99% reductions in reproductive biomass’. There
ciently far back into history; Pauly 1995) is much more    are at least 3 major problems associated with the
prevalent in terrestrial systems than marine. A 50%      analyses in Hutchings’ paper that may undermine
decline in a population that has already declined by     his conclusions. First, Hutchings defined a depletion
99% from its pre-exploitation level is likely to be far    phase as the largest 15 yr percentage decline in
more serious in terms of risk of extinction than a 50%    mature fish biomass experienced by each of the stocks
decline from a more or less unexploited state. Even so,    included in his analysis, without regard for the extent
IUCN (2001) and others advocate evaluating declines      of depletion at the starting point of each time series.
only over the past 10 years or 3 generations (whichever    Second, he then interpreted subsequent 5, 10 and 15 yr
is longer). While the suddenness and rapidity of de-     periods as potential recovery periods, without regard
clines may be important, longer historical perspectives    to whether or not there was any attempt to rebuild the
must also be considered.                   resources by reducing fishing mortalities. Third, the
  In addition, although declines substantially greater    time series in the database used for his analyses have
than 50% of the unexploited level probably require      not been updated since the early 1990s and therefore
correction, they often only tell part of the story for com-  do not capture the successes of that decade and
mercially exploited marine species. For example, there    beyond.
has recently been considerable concern about the         In the last 10 to 15 yr, there have been several con-
extent of decline of the spiny dogfish Squalus acan-     certed and successful efforts to bring fishing mortali-
thias off the Atlantic coasts of the United States and    ties under control. These have provided ample evi-
                               dence that reductions in fishing mortality can lead to
Canada (to the extent that some U.S. environmental
NGOs have proposed that it be listed on the Appen-      recovery of depleted marine resources (Table 2). One
dices of the Convention for the International Trade in    of the most dramatic examples is Georges Bank scal-
Endangered Species of Fauna and Flora). According to     lops, for which fishing mortality has been reduced from
the most recent stock assessment (NOAA 2003b), the      a peak of about 1.74 in 1991 to an historic low of 0.09
biomass of mature females declined by about 78%        in 2002, and biomass has responded by increasing
from 270 000 t in 1991 to 58 000 t in 2002. However, the   more than 23-fold over the same time period (D. Hart,
number of individuals comprising the mature female      NOAA, pers. comm.). Similar, but less spectacular,
biomass in 2002 was about 22 million. Similarly, the     results have been observed on Georges Bank for
exploitable biomass (both sexes) in 2002 comprised      haddock, yellowtail flounder, and winter flounder
about 63 million individuals, while the total biomass     (Table 2). Even the local barndoor skate, a species
comprised about 224 million individuals (P. Rago,       declared by Casey & Myers (1998) to be ’close to
NOAA, pers. comm.). Thus, although there may have       extinction’, is now estimated to number several million
been large percentage declines, the absolute numbers     individuals (K. Sosebee, NOAA, pers. comm.).
288                      Mar Ecol Prog Ser 274: 269–303, 2004




 As an aside, it is interesting to briefly examine the       scallops, other management measures have included
role of MPAs in the Georges Bank scallops success          imposition of limited entry, a 41% reduction in allow-
story. Although some authors (e.g. Gell & Roberts 2003)       able fishing days, an average of about a 40% reduction
have used Georges Bank scallops as an example of the         in vessel crew size (which substantially limits the
successful application of marine reserves (no fishing        amount of product that can be caught and processed
areas), this is only a part of the story. The 17 000 km2 of     each day), and new gear regulations to reduce catches
areas closed to groundfish and scallop fishing on          of small scallops (D. Hart, NOAA, pers. comm.). So far,
Georges Bank in late 1994 (covering about 50% of the         the spillover benefits often attributed to marine re-
productive area for scallops and 30% for groundfish)         serves (e.g. increased landings) have not been realized.
was only 1 component, albeit a very important compo-         The combined effect of the new management measures
nent, of the suite of management measures that has led        has been to reduce total landings from an average of
to observed reductions in fishing mortality and sub-         7472 t for the 5 yr prior to the imposition of the new
sequent increases in total biomass. For Georges Bank         management measures to 5006 t over the most recent

Table 2. Fish and invertebrate stocks that have exhibited substantial increases in biomass (B) following substantial reductions in
fishing mortality (F). In a few cases, a survey biomass catch rate, B(index), is used as a proxy for stock biomass (units = kg per
survey tow) and an exploitation rate index (E) is used as a proxy for F (units = kg of catch / kg per survey tow). Index results
should be treated as highly uncertain as they have not been filtered through a stock assessment model. SSB is spawning stock
biomass. Units of B or SSB are tonnes unless otherwise indicated. In 2 cases, absolute numbers (N) are used as a proxy for
biomass. For all variables (F, E, B, SSB, and N), the first set of subscripts represents the ages over which the values are averaged,
and the second set of subscripts represents the years over which the values are averaged. When the values are based on the fully
recruited biomass (i.e. that portion of the total biomass that is vulnerable to the fishery) or the spawning stock biomass, the
first set of subscripts is omitted. The convention adopted for choosing the years over which to average was to use single year esti-
mates if the values were monotonically increasing or decreasing, but to average over several relevant years if the values were
                     fluctuating without trend around high or low points


Common name/                                          Fishing mortality (F)
Species name                             Maximum          Recent     Magnitude of reduction

Georges Bank scallops Placopecten magellanicus            F91 = 1.74        F03 = 0.09        19.3
U.S. mid-Atlantic scallops P. magellanicus              F92 = 1.58        F03 = 0.48         3.3
Georges Bank cod Gadus morhua                     F4 – 8, 94 = 1.49     F4 – 8, 00 – 01 = 0.37   4.0
Gulf of Maine cod G. morhua                      F4 – 5, 94 = 2.04     F4 – 5, 01 = 0.47     4.3
Georges Bank haddock Melanogrammus aeglefinus             F4 – 7, 80 – 93 = 0.37  F4 – 7, 95 – 01 = 0.16   2.3
Gulf of Maine haddock M. aeglefinus                  E90 – 93 = 0.98      E00 – 01 = 0.11      8.9
Georges Bank yellowtail flounder Limanda ferruginea          F4 – 5, 94 = 2.56     F4 – 5, 01 = 0.13     19.7
Gulf of Maine yellowtail flounder L. ferruginea            F3 – 4, 88 = 1.40     F3 – 4, 99 – 01 = 0.63   2.2
Georges Bank winter flounder Pseudopleuronectes americanus      F93 = 0.71        F99 – 01 = 0.20      3.6
Gulf of Maine winter flounder P. americanus              F5 – 6, 95 = 1.85     F5 – 6, 99 – 01 = 0.11  16.8
Mid-Atlantic winter flounder P. americanus              F4 – 5, 97 = 1.23     F4 – 5, 01 = 0.51     2.4
U.S. Atlantic witch flounder Glyptocephalus cynoglossus        F7– 9, 96 = 0.96     F7– 9, 99 – 01 = 0.40   2.4
Gulf of Maine / Georges Bank windowpane flounder           E90 – 93 = 5.92      E99 – 01 = 0.10      59.2
  Scophthalmus aquosus
U.S. Atlantic Acadian redfish Sebastes fasciatus           E81– 85 = 1.19      E00 – 01 = 0.013     91.5
U.S. Atlantic silver hake Merluccius bilinearis            E63 – 72 = 11.56     E89 – 99 = 0.42      27.5
U.S. Atlantic summer flounder Paralichthys dentatus          F3 – 5, 83 = 2.15     F3 – 5, 02 = 0.23      9.3
U.S. Atlantic striped bass Morone saxatilis              F1+, 75 – 80 > 0.5    F1+, 87– 01 = 0.16    > 3.1<
Georges Bank / Gulf of Maine herring Clupea harengus         F61– 75 > 0.5       F97 = 0.05        >10.0<
U.S. Gulf of Mexico king mackerel Scomberomorus cavalla        F0 –11, 81– 85 = 0.19   F0 –11, 97– 01 = 0.15    1.3
U.S. Atlantic sandbar shark Carcharhinus plumbeus           F88 – 94 = 0.18      F99 – 01 = 0.082      2.2
U.S. Atlantic blacktip shark Carcharhinus limbatus          F88 – 94 = 0.064     F99 – 01 = 0.031      2.1
California sardine Sardinops sagax                  F46 – 65 = 0.88      F83 – 02 = 0.13      6.8
New Zealand Area 2 snapper Pagrus auratus               F80 = 0.69        F98 – 00 = 0.17      4.1
New Zealand Area 7 snapper P. auratus                 F78 – 81 = 0.26      F98 – 00 = 0.0088     29.5
North Atlantic swordfish Xiphias gladius               F1+, 95 = 0.56      F1+, 00 = 0.31       1.8
North Sea saithe Pollachius virens                  F3 – 6, 86 = 0.83     F3 – 6, 02 = 0.21      4.0
North Sea herring Clupea harengus                   F2 – 6, 73 – 76 = 1.27  F2 – 6, 78 – 02 = 0.44   2.9
Irish Sea herring C. harengus                     F2 – 6, 74 – 80 = 0.92  F2 – 6, 84 – 02 = 0.37   2.5
Norwegian spring herring C. harengus                 F5 –14, 67– 72 = 1.65   F5 –14, 88 – 02 = 0.12  13.8
Icelandic summer herring C. harengus                 F5 –15, 64 – 71 = 1.11  F5 –15, 81– 02 = 0.25    4.4
South African sardine Sardinops sagax                 F0+, mid – 60s > 0.35   F0+, 90 – 02 = 0.064   > 5.5<
                                                                 289
             Theme Section: Ecosystem-based approaches to management of marine resources




5 yr. In fact, recent landings would have been even           globally. As Table 2 demonstrates, single species bio-
lower if not for temporary re-openings of the ‘closed’         mass levels can be rebuilt as a result of concerted
areas during 1999–2001. The extent to which the             efforts to reduce fishing mortality; the problem is that,
dramatic increase in scallop biomass is the result of the        to date, there have been insufficient concerted efforts
establishment of MPAs per se, or to the contribution of         to reduce single-species fishing mortalities. When it
the MPAs to observed reductions in fishing mortality,          has not been possible to bring fishing mortality under
warrants further analysis. However, it should be noted         control, stocks have generally continued to decline or
that mid-Atlantic scallops have also experienced sub-          have remained depleted. Unfortunately, there are also
stantial increases in biomass, concurrent with substan-         several examples (a much smaller number) of stocks
tial reductions in fishing mortality (Table 2), without the       that have not recovered following substantial re-
benefit of permanent closed areas.                   ductions in fishing mortality. An oft-cited example is
  Other examples of partial or complete recoveries of         Northern cod, which has failed to rebuild despite a
marine fish and invertebrate stocks for which fishing          moratorium on fishing that began in 1992, with only
mortality has been substantially reduced are provided          limited subsequent re-openings. Although Northern
in Table 2, together with estimates of the extent of          cod is an important counter to the examples provided
reduction in fishing mortality and the extent of re-          in Table 2, it should not be portrayed as the norm.
covery in biomass. Although this is not an exhaustive           The real problems. There are 4 major problem areas
list (e.g. Caddy & Agnew 2003 provide several addi-           that need to be addressed to ensure robust and pro-
tional examples), the sum total of all success stories of        ductive marine fisheries and ecosystems for now and
this nature represents only the tip of the iceberg in          the future. These apply regardless of whether single-
terms of the number of stocks that need to be restored         species or ecosystem-based approaches are employed.


                             Table 2 (continued)


                Biomass (B)                    Source
Mimimum           Recent          Magnitude of increase

B93 = 4500          B01– 03 = 105 200         23.4        D. Hart, NOAA, pers comm.
B90 – 97 = 3900       B00 – 03 = 66 700         17.1        D. Hart, NOAA, pers. comm.
SSB95 = 17 400        SSB01 = 29 200           1.7        NOAA (2002)
SSB98 = 10 600        SSB01 = 22 000           2.1        NOAA (2002)
SSB93 = 11 300        SSB01 = 74 400           6.6        NOAA (2002)
B(index)90 – 93 = 0.28    B(index)00 – 01 = 13.01      46.5        NOAA (2002)
SSB95 = 2300         SSB01 = 38 900          16.9        NOAA (2002)
SSB01 = 1600         SSB97 = 3200            2.0        NOAA (2003a)
B93 = 2400          B01 = 9800             4.1        NOAA (2002)
SSB95 = 700         SSB01 = 5900            8.4        NOAA (2003a)
SSB94 = 2700         SSB01 = 7600            2.8        NOAA (2003a)
SSB95 = 4000         SSB01 = 11 400           2.9        NOAA (2002)
B(index)91 = 0.17      B(index)01 = 0.92         5.4        NOAA (2002)

B(index)82 – 85 = 4.3    B(index)00 – 01 = 27.2        6.3       NOAA (2002)
B(index)64 – 71 =3.42    B(index)98 – 99 = 16.80       4.9       NOAA (2001); L. Jacobson, NOAA, pers. comm.
SSB89 = 5200         SSB02 = 42 200           8.1       Terceiro (2003)
B1+, 82 – 83 = 6880     B1+, 99 – 01 = 103 700      15.1        G. Shepherd, NOAA, pers. comm.
Bmid 70s < 100 000      B97 = 2 900 000         > 29.0<       Overholtz (2000)
B0 –11, 85 = 21 600     B0 –11, 01 = 36 000         1.7       M. Ortiz, NOAA, pers. comm.
N95 = 1 282 200       N01 = 1 466 000           1.1       Cortés et al. (2002); E. Cortés, NOAA, pers. comm.
N95 = 7 899 700       N01 = 8 204 100           1.0       Cortés et al. (2002); E. Cortés, NOAA, pers. comm.
B1+, 83 = 5100        B1+, 99 – 02 = 980 400      192.20       MacCall (1979); Conser et al. (2002)
SSB81 = 1200         SSB01 = 4000             3.3       Gilbert & Phillips (2003)
SSB80 = 5500         SSB01 = 22 800            4.1       Gilbert & Phillips (2003)
B1+, 96 = 34 200       B1+, 00 = 49 700          1.5       ICCAT (2003)
SSB91 = 92 800        SSB03 = 364 000           3.9       ICES (2003)
SSB77 = 48 100        SSB03 = 2 231 000         46.4       ICES (2003)
SSB80 = 5700         SSB99 – 03 = 12 100         2.1       ICES (2003)
SSB72 = 313 000       SSB95 – 03 = 5 896 200       18.8       ICES (2003)
SSB68 – 72 < 20 000     SSB03 = 526 200         > 26.3<       ICES (2003)
SSB84 = 42 200        SSB02 – 03 = 3 690 600       87.5       Cunningham & Butterworth (2004)
290                    Mar Ecol Prog Ser 274: 269–303, 2004




  (1) Excessive fishing mortality rates: Fishing mor-    than lack of adequate models, be they single-species
tality rates in excess of 2 to 3 times the single-species   or ecosystem level.
                                 (4) Lack of adequate governance systems: Here,
optimum have been common in the past (Table 2,
Mace 2001, NOAA 2002, ICES 2003b), and still exist in     governance is interpreted in the broad sense to include
many fisheries.                        formal and informal rules adopted by the fishing
  (2) Overcapacity: The problems associated with       industry, fisheries scientists, and the public, in addition
overcapacity extend well beyond those related directly    to the rules used for fisheries management (Sissenwine
to economic efficiency and financial viability of fishing   & Mace 2003). Codes of practice need to be formally or
fleets. Although in theory overcapacity need have no     informally developed and adhered to by all relevant
implication for resource conservation provided that a     players. Fishermen need to implement responsible
total allowable catch (TAC) or similar constraint is     fishing practices, fisheries managers need to imple-
set and enforced appropriately, in reality overcapacity    ment responsible fisheries management, fisheries
can seriously compromise fisheries management and       scientists need to produce responsive and credible
enforcement, and may ultimately compromise the        scientific advice, the public needs to get more involved
validity of stock assessments. Participants in fisheries   in the fisheries management process and to better
that are barely financially viable are more likely to: put  appreciate the level of information required to achieve
pressure on fisheries managers to choose TACs from      an appropriate balance between exploitation and con-
the upper range of confidence intervals or risk analy-    servation, and politicians need to have the political
ses; challenge the validity of the science; underreport    will to create effective legislation and live by it (Sissen-
landings; have higher discard rates in order to maxi-     wine & Mace 2003).
mize the value of landings; cause higher mortality of      Progress. In the last 10 to 15 yr, programs to reduce
discards due to lack of time available for careful      fishing mortality rates have intensified and some are
handling of discards; cause higher cryptic mortality by    resulting in recovery of depleted fish stocks (Table 2).
using unnecessarily large amounts of fishing gear;      A few of these successes have been accomplished
cause greater amounts of ghost fishing from lost or      despite the existence of substantial fleet overcapacity.
abandoned fishing gear; and cause more damage to       However, experience has demonstrated that the most
marine habitats by deploying more fishing effort than     effective method for bringing fishing mortality under
necessary (Mace 2001). Various authors (e.g. Garcia &     control is to eliminate overcapacity. In turn, the most
Newton 1996, Mace 1997) have estimated the current      effective method for bringing fishing capacity under
global fishing capacity at 11⁄2 to 2 times the optimum,    control is to develop and implement appropriate
based on single-species considerations alone. At a      rights-based systems, i.e. to implement effective gov-
minimum, fishing capacity needs to be reduced to       ernance. These rights have taken a number of forms
levels commensurate with the productivity of the       ranging from Individual Transferable Quotas (ITQs) to
resources being exploited.                  community-based co-management. With such rights,
  (3) Lack of adequate basic data: Lack of knowledge     participants should have a greater incentive to con-
about marine systems is one of the major obstacles to     serve the fishery resource for the future. Examples of
effective decision-making. Even though the precau-      successful reductions in fishing capacity following
tionary approach (FAO 1995b) dictates that greater      introduction of rights-based management include New
uncertainty should be addressed by exercising greater     Zealand’s inshore fisheries, and various fisheries in
caution, in reality it would be very difficult for fish-   Australia, the United States, Canada, Iceland and
eries managers to claim something like, ‘we know ab-     Chile. Two cases where substantial reductions in fish-
solutely nothing about the effect of current catches on    ing capacity have occurred in the absence of rights-
the biomass of this species; therefore, we are going to    based management are the former Soviet Union,
slash the quota’. The single most valuable tool for      which no longer had the resources to maintain its
assessing the status of individual stocks, biological     aging distant water fleet following dissolution, and
communities, and habitats has proven to be consistent     Japan, which has actively reduced the size of its
time series of data on catches, relative abundance, size   distant water fleet in recent years.
distributions, and other biological and physical infor-     The prognosis for further reducing fishing mortality
mation. Unfortunately, few such time series exist. In     rates, eliminating overcapacity and improving gover-
particular, long-term, fishery-independent data have     nance has also improved appreciably with the recent
only been collected in a few scattered instances, pri-    escalation of international instruments such as the
marily in developed countries. Without these data, we     1993 Convention on Biological Diversity, the 1993
run the risk of severely depleting or totally eliminating   Agreement to Promote Compliance with International
species, without even being aware of it until it is      Conservation and Management Measures by Fishing
too late. Lack of adequate data is more problematic      Vessels on the High Seas, the 1995 Straddling Stocks
                                                                 291
            Theme Section: Ecosystem-based approaches to management of marine resources




Agreement (United Nations 1995), and several FAO         to thank those who responded at short notice to my requests
                                 for stock assessment information, including Enric Cortés,
International Plans of Action including the 1999 Inter-
                                 Carryn Cunningham, Dave Gilbert, Dvora Hart, Larry Jacob-
national Plan of Action for the Management of Fishing
                                 son, Ram Myers, Mauricio Ortiz, Paul Rago, Gary Shepherd,
Capacity and the 2001 International Plan of Action        Kathy Sosebee and Mark Terceiro.
for Illegal, Unreported and Unregulated Fishing. Even
non-binding agreements such as the FAO Interna-
tional Code of Conduct for Responsible Fisheries (FAO       Moving beyond ’intelligent tinkering’:
1995a) are gradually changing the mind-set of fishing       advancing an Ecosystem Approach to
nations towards more responsible fishing practices.
                                        Fisheries
  The lack of adequate monitoring of marine species,
                                      Michael Sissenwine1, Steven Murawski2
habitats and oceanographic factors is perhaps the most
difficult problem of all to address, primarily because of     1
                                    NOAA-Fisheries, 1315 East-West Highway, Silver Spring,
the prohibitive costs associated with conducting surveys              Maryland 20910-3282, USA
of marine resources and the high costs of simply moni-             Email: michael.sissenwine@noaa.gov
toring catches in many countries. Realistic cost-benefit      2
                                    NOAA-Fisheries, Woods Hole, Massachusetts, 02543, USA
analyses may well indicate that the costs of comprehen-             Email: steve.murawski@noaa.gov
sive scientific research far exceed both short- and long-
                                  In his classic 1953 essay, Round River, the American
term potential economic benefits to the fishing industry.
As a result, while a few countries may be improving their    conservationist Aldo Leopold illustrated the challenge
monitoring capabilities (e.g. the United States), others     of expanding concepts of living resource management
are losing funds for research and monitoring. Recent       to include consideration of non-target species and
progress includes several ambitious programs under the      ecosystem-level linkages:
auspices of the Global Ocean Observing System              If the biota, in the course of aeons, has built some-
(GOOS), Global Ocean Ecosystem Dynamic Programs             thing we like but do not understand, then who but a
                                    fool would discard seemingly useless parts? To keep
(GLOBEC), and the Census of Marine Life (CML).
                                    every cog and wheel is the first precaution of intelli-
  Concluding remarks. Holistic, ecosystem-based ap-
                                    gent tinkering.            (Leopold 1966)
proaches are obviously required to manage marine
resources. However, marine ecosystems are complex          In this quote, Leopold introduces both the concepts
and poorly understood, and the most pressing prob-        of uncertainty in how ecosystems are organized, and
lems are similar regardless of whether one considers       the use of precaution in the face of uncertainty. Since
individual species or whole systems. We need to         Leopold penned his essay 50 yr ago, marine fisheries
develop ecosystem-based approaches to fisheries that       have relied heavily on single-species assessments of
build upon and integrate ‘traditional’ single-species      population size and harvest rate to evaluate resource
objectives, not solutions that abandon traditional        status as a basis for advising management (e.g. Mace
approaches that have never been fully implemented,        1994, Gabriel & Mace 1999, Mace 2001). This ap-
in favor of what are often ill-defined concepts that may     proach focuses on the most visible ‘cogs and wheels’ of
do little to solve the overall problems and may not be      Leopold. Many have condemned these traditional
operational. Therefore, I advocate ecosystem-based        single-species paradigms, given the current state of
approaches with single-species models and opera-         the world’s living marine resources (FAO 2002a). How-
tional single-species objectives embedded as an         ever, most cases of resource failure have resulted from
important component. We need to work on bringing         inadequate institutional controls and not from biologi-
fishing mortality under control, eliminating overcapac-     cal targets that were incorrectly or overoptimistically
ity, collecting more and better data, and improving       determined (Sissenwine & Mace 2003, Hilborn 2004
governance systems, at the same time as we explore        in this TS).
the utility of so-called ecosystem-based approaches         Species of economic, or other intrinsic value to society,
such as MPAs which, by themselves, may or may not        are embedded within complex ecosystems. Over the past
result in the restoration of depleted fish stocks and      30 yr, fisheries science and management have increas-
ecosystems (see Sissenwine & Murawski 2004 in this        ingly recognized these interactions and accommodations
TS). As Hilborn (2004 in this TS) and Jennings (2004 in     for them have been added to management programs —
this TS) assert, the emphasis should be on evolution,      though not necessarily under an ecosystem appellation.
not revolution.                         Today, it is common for fisheries management to address
                                 a wide array of factors in addition to single species stock
Acknowledgements. This paper has benefited immensely
                                 dynamics. As early as the 1970s, the International Con-
from comments on earlier drafts received from Doug Butter-
                                 vention for the Northwest Atlantic Fisheries (ICNAF) in-
worth, Kevern Cochrane and, in particular, the editors of this
                                 stituted a ’second-tier’ quota to at least symbolically take
TS, Howard Browman and Kostas Stergiou. I would also like
292                     Mar Ecol Prog Ser 274: 269–303, 2004




account of species interactions, and similarly there has     the species or processes of interest. Even with this
been a cap on the multispecies catch of Bering Sea        simplification, the issues remain daunting.
groundfish since the 1980s. There are numerous exam-        How should ecosystems be delineated? To apply
ples of regulations to reduce bycatch (particularly for     an ecosystem approach, it is necessary to delineate
birds, turtles and mammals) and destructive fishing       ecosystems. The scale of these ecosystems should be
practices. Although less common, there are also exam-      based on the spatial extent of the system dynamics that
ples of trophic interactions and climate variability being    are to be studied and/or influenced through manage-
explicitly taken into account in fisheries management.      ment. Specific ecosystem boundaries are based on
With respect to uncertainty, the precautionary approach     discontinuities in the geographic distribution of eco-
has been operationalized in many cases, with prudent       system characteristics and management jurisdictions.
reference points established to guide management.        This will lead to specifying ecosystems at a hierarchy
However, efforts to advance beyond a single-species ap-     of scales with boundaries that sometimes overlap.
proach have generally emerged in a piecemeal manner         What primary issues will be addressed under an
in response to challenges to the legitimacy of fishing.     EAF? Incorporation of ecosystem-based approaches
Some regions of the world are advancing much more        into fisheries management involves accounting for a
rapidly than others. Worldwide, it is fair to say that fish-   number of important classes of interactions that are not
eries management is becoming increasingly intelligent      routinely evaluated in current species-by-species or
in the way it tinkers with ecosystems, although there are    fishery-based management programs.
                                  Bycatch or fishery interactions: Bycatch and fishery
polarized views on how rapidly progress is being made.
  In this essay we consider (1) requirements for        interactions, including mortalities of non-target spe-
advancing ecosystem-based approaches beyond the         cies, arise when multiple fisheries share the same spe-
intelligent tinkering stage and (2) the roles of marine     cies. Discards are usually incorporated into single-
protected areas.                         species stock assessments (when reliable data are
                                 available). However, few management programs
  What is an Ecosystem Approach to Fisheries (EAF)?
We believe that an EAF is one that is geographically       explicitly consider the total value of the catch from
specified, adaptive, takes account of ecosystem knowl-      systems of competing fishing activities.
                                  Indirect effects of harvesting: An important class of
edge and uncertainties, considers multiple external in-
fluences, and strives to balance diverse societal objec-     indirect harvesting effects on ecosystems involves
tives.1 Implementation will need to be incremental and      alterations of feeding relationships and energy flows
collaborative. The term ’Ecosystem-Based Fisheries        between trophic levels. Negative effects (a ‘trophic
Management (EBFM)’ is often used, but recently, the       cascade’; Carpenter 2003) can result if fishing alters
FAO concluded that it was better to use an ‘Ecosystem      the balance between predators and their prey. Indirect
Approach to Fisheries - EAF’ (FAO 2003, Garcia et al.      effects also include impacts of fishing practices that
2003). The latter terminology conveys an important        alter the functional value of vulnerable habitats.
                                  Interactions between biological and physical com-
point. What we are discussing is an approach or process
                                 ponents of ecosystems: Environmental variation (in
that explicitly takes account of ecosystem processes in
the formulation of management measures. The actual        trend and amplitude) is an important component that
management actions that emerge may or may not be         has critical implications for the resilience and pro-
qualitatively different from traditional management ac-     ductivity of marine ecosystems. Trends in environmen-
tions (e.g. a total allowable catch may still be the primary   tal variables (e.g. temperature, other oceanographic
conservation tool), but they are likely to be quantitatively   attributes) may drive long-term re-structuring of spe-
different as a result of taking account of more factors.     cies assemblages, whereas high amplitude variations
  Evolving management approaches to incorporate         (e.g. in recruitment) induce local instabilities or distri-
ecosystem-related issues requires extending the man-       bution shifts of biological components. Regime shifts
dates of existing management institutions. These insti-     in biological productivity may occur due to sudden,
tutions must thus address broader societal objectives      significant environmental change, or as a result of
than previously, and be responsive to a broader com-       harvest-induced changes in biological communities
munity of stakeholders. Such an approach focuses         (Steele 1998, Scheffer & Carpenter 2003). The re-
effort on understanding the effects of biotic and abiotic    versibility of regime changes is not guaranteed. Life
interactions on some subset of species, and second,       history, environmental variation and fishing strategies
limits the scope of management related activities to       interact in complex ways to affect the stability of bio-
those things likely to have a meaningful impact on        logical communities. For example, low rates of harvest
                                 may lead to biological community structures that
                                 are more resistant to environmental fluctuation, by
1
  This definition of an Ecosystem Approach has been adopted
                                 extending the age profile of long-lived species.
  by our Agency
                                                          293
           Theme Section: Ecosystem-based approaches to management of marine resources




  Each of the above classes of interaction effects may    mortality. However, we are aware of no evidence (nor
be important when ecosystem objectives associated       logical reason) to support the conclusion that MPAs will
with them are incorporated into management pro-        be a more robust tool to control overall fishing mortality
grams. One type of tool that has been widely proposed     than would other methods.
as being relevant to an ecosystem approach is Marine       Perhaps more important is the issue of the effective-
Protected Areas (MPAs). Below, we provide some        ness of MPAs. For species that are highly mobile, one
thoughts on the role that MPAs can play in developing     would expect MPAs to be quite ineffective. Animals
ecosystem-based approaches.                  that are protected within the boundaries of MPAs are
                               vulnerable when they migrate out of the protected
  MPAs — are they synonymous with an ecosystem
approach to fisheries? MPAs and EAF are so often dis-     area — fishing fleets could simply concentrate their
cussed together that one might think they are synony-     effort on the edges to take advantage of these disper-
mous (e.g. Botsford et al. 1997, Allison et al. 1998,     sive movements (Gell & Roberts 2003, Murawski et al.
Palumbi 2002). However, MPAs are just one of a suite     2004). At the opposite extreme, sessile species may
of fishery management tools that have merit (and limi-    thrive within protected areas, but they may not benefit
tations) for either single-species approaches to man-     the fishery since they cannot be caught. Eggs and lar-
agement, or for ecosystem approaches (EAF). While       vae that drift out of an MPA may serve to repopulate
MPAs are an obvious measure to consider when valu-      other areas, thus eventually benefiting the fishery. The
able biological, physical or cultural resources are      potential yield from a sessile population straddling
located in discrete areas, there may be severe down-     both open and permanently closed areas is likely to be
sides to their indiscriminant use (discussed below).     lower than it would have been using other means of
  For the most part, MPAs (and other forms of area      controlling fishing mortality, since animals in the open
closures) have been used to (1) control fishing mortal-    areas cannot be fished harder to compensate for the
ity on target species, (2) reduce bycatch and wasteful    proportion of the population that is unavailable. This is
discards, and (3) protect vulnerable habitats and bio-    because fishing the fraction of animals in open areas at
diversity. The relevance of MPAs to these 3 objectives    higher rates could result in growth overfishing and loss
is discussed below.                      of yield potential (e.g. see Hart 2003 for a discussion of
  Controlling the fishing mortality rate on target spe-   these issues relative to the management of sea scallop
cies: Controlling fishing mortality, and manipulating its   Placopecten magellanicus on Georges Bank). This
application on particular size or age classes, are the    phenomenon would also likely apply to some finfish
keys to achieving the typical objectives of sustain-     that have limited home ranges (Gell & Roberts 2003).
ability, high yield, and efficiency. Often, this is done by   For species between the extremes of being sessile
setting a Total Allowable Catch (TAC) based on the re-    and highly mobile, MPAs should be relatively more
lationship between catch and fishing mortality. Another    effective in terms of conservation, with less sacrifice of
approach is to limit fishing effort (days at sea or some   potential yield. However, to be effective, the area that
other effort metric) since fishing mortality is propor-    needs to be protected may be much larger than the
tional to effort. Controlling fishing mortality through    20% level that has been discussed by some authors.
either a TAC or limit on fishing effort requires consider-  For example, Lauck et al. (1998) show that 50% or
able scientific information about the fishery and re-     more of a population’s range may need to be protected.
source species. This is the type of information that is    This point is also illustrated by fisheries management
routinely collected for fisheries conducted by devel-     on Georges Bank. Protected areas (referred to as
oped countries, but it is rarely available in developing   closed areas) have played a critical role in efforts to
countries. Even in relatively data-rich situations, TACs   rebuild depleted groundfish stocks. Clearly, the efforts
and/or effort limits, are sometimes set incorrectly be-    are working for some species (Georges Bank haddock
                               Melanogrammus aeglefinus, and yellowtail flounder
cause of limitations in the scientific information to sup-
                               Limanda ferrugineus). However, about 30% of the
port them or in the governance institutions that utilize
such findings. Thus, it is tempting to propose MPAs as a   most productive fishing grounds had to be closed, and
more robust (to scientific uncertainty and management     it was still necessary to cut fishing effort by 50% or
failure) fisheries management approach. This is some-     more on some species (occurring primarily outside the
times referred to as an insurance policy (Lauck et al.    closed areas) due to excessive fishing capacity and the
1998, Murray et al. 1999, NRC 1999b, Ward et al. 2001).    effects of displaced effort (Murawski et al. 2000).
Of course, one can establish an MPA with little scien-      There also may be economic and social issues that
tific information and expect to constrain fishing mortal-   are unique to the use of MPAs as a tool to limit fishing
ity to some degree. Similarly, one can use other fishery   mortality. Since MPAs usually force fishing into areas of
management tools with little scientific information and    lower fish density, the cost per unit of catch may in-
achieve some unspecified degree of control over fishing    crease. In this context, MPAs are likely to be less effi-
294                    Mar Ecol Prog Ser 274: 269–303, 2004




cient than other measures. In addition, MPAs may lead     adverse impact on future productivity (although there
to disproportionate economic impacts on less mobile      is currently little compelling evidence of this). Fishing
and flexible gears and vessels, particularly if they are   may also potentially alter and/or destroy the habitat of
located inshore where traditional small scale or artisinal  non-target species and, thereby, negatively affect bio-
fisheries once operated. Nevertheless, all management     diversity and biogenic structures. A high-profile exam-
measures impose costs on the industry, and these costs    ple of this is deep/cold-water corals that are vulnerable
are usually bourn disproportionately by some sectors.     to destruction by fishing.
  Reducing bycatch and wasteful discards: Catching       MPAs can be useful for protecting habitat and bio-
and discarding non-target species, or individuals of tar-   diversity. They are most effective when specific and
get species that are too small to be desirable or that are  localized areas can be identified where habitats of
otherwise prohibited, is a widely recognized problem.     particular concern are vulnerable to fishing, or where
Discarding wastes production, potentially causes ad-     there are biodiversity ‘hot spots’. However, a major
verse effects on ecosystem function, distorts allocations,  challenge in using MPAs to protect habitat and bio-
and raises ethical and legal concerns. Closing areas to    diversity is the lack of suitable geographically resolved
fishing where there is an unacceptable likelihood of un-   information. Another problem is that we generally lack
desirable bycatch is a widely used, and often effective,   scientific evidence relating habitat attributes to the
fishery management approach. For example, there are      productivity of a species. The relationship between
extensive ‘rolling’ closures off the east coast of the    biodiversity and ecosystem function is also poorly
U.S. to reduce harbor porpoise Phocoena phocoena       understood. Nevertheless, it seems prudent to protect
bycatch in gill nets. Similarly, there are exclusion zones  the habitat, and biodiversity hot spots, that seem most
in Alaskan waters to reduce trawl-induced bycatch       unique and vulnerable to fishing gear. However, this
mortalities on crabs, mammals and other species. In the    raises a dilemma: the more advanced we become in
North Sea, the use of species-specific ‘boxes’ are like-   mapping habitat and biodiversity, the more we realize
wise intended to reduce catches of undersized animals,    that some forms that were once thought rare may actu-
and for other conservation purposes.             ally be common. For example, when we knew little
  While MPAs can be a useful tool to reduce bycatch     about the distribution of deep/cold-water corals —
and wasteful discarding, there are alternative ap-      believing that they were relatively rare — it seemed
proaches have been employed. In general, reducing       reasonable to protect all of the known areas where
fishing mortality to target rates that are consistent with  they occurred. We now know that deep/cold water
life history and productivity will reduce bycatch. From    corals are more common than previously thought (ICES
a conservation point of view, it seems likely that if the   2002a,b), and so the question now becomes: what
fishing mortality on the target species is limited to a    degree of protection is appropriate for them?
level that produces a relatively high yield on a sustain-    The uses of MPAs as a primary management tool to
able basis (such as MSY), then bycatches will not be     address the issues noted above need to be carefully
problematic for co-occurring species with similar life    considered, both in terms of actual benefits and costs
histories (even if they are not targets, and are thus     (relative to alternative management measures). MPAs
discarded). Of course, this is why bycatch is a threat to   may be the only way to achieve some goals. However,
long-lived species (such as mammals and turtles), even    the effects on the system of displaced effort may have
when the target species is not overfished.          other, unanticipated, negative impacts.
  Another way to reduce bycatch and wasteful discard-      Conclusions. The EAF is not a revolutionary new type
ing is by redesigning fishing gear to minimize catches    of management scheme that necessarily takes a direc-
of non-target species. Such ‘conservation engineering’    tion different from the path along which fisheries man-
is widely used, and sometimes quite successful (e.g.     agement has been evolving. It is, however, a much more
reducing the bycatch of sea turtles caught by fishing     inclusive approach in terms of the diversity of stake-
vessels targeting shrimp in the Gulf of Mexico, and by    holder involvement. If management of living resources is
pelagic longline fisheries in the northwest Atlantic).    to move significantly beyond a focus on high-profile
  All of these factors make deciding which approach to    stocks or assemblages of economically important spe-
apply to reduce bycatch complex, and dictated by       cies, then there is a pressing need both for science and
cumulative costs, benefits and the ability to enforce     governance institutions to evolve. Increasing emphasis
regulations that will ensure their effectiveness.       on EAF provides a useful bridge between the traditional
  Protecting habitat and enhancing biodiversity: It is    single-species basis, and ‘ecosystem management’,
increasingly recognized that fishing alters habitat and    which implies considerations of human activities well
affects biodiversity, directly or indirectly. In some     beyond the scope of most resource-based institutions.
cases, the concern is over habitat of importance to       MPAs, and other forms of area closures, are useful
the fished species. Altering this habitat might have     tools for managing fisheries, and they will probably
                                                           295
            Theme Section: Ecosystem-based approaches to management of marine resources




take on an even greater role under the EAF (NRC         2003). Thus, after a brief summary of overfishing, we
2001). They have a long history as part of the suite of     will discuss what we believe is the more fundamental
tools used to control fishing mortality, reduce bycatch,    issue underlying the problem.
and mitigate fishery interactions. However, their use       The generally invoked causes of global overfishing
as a management tool is not inherently any more         are: overcapacity and excessive effort by fishing fleets
appropriate, nor are some of their limitations any       (Garcia & de Leiva Moreno 2003), driven by subsidies
less consequential, under ecosystem versus traditional     (Munro & Sumaila 2002) and technology ‘stuffing’,
species-based management approaches.              which increases the ability of fleets to fish in habitats
 An EAF and MPAs are not synonymous, nor are they       and at depths previously off-limits, and dramatically
panacea. However, the potential synergism between        amplifies the catching ability of gears (Valdemarsen
them is strong. The increasing attention they are        2001, Garcia & de Leiva Moreno 2003). This con-
receiving is indicative of society’s struggle to make      tributes to the problems associated with ‘fishing down
wise decisions about diverse human activities that       marine food webs’ (Pauly et al. 1998), and removes
have uncertain consequence for complex marine          the last natural refuges for many resource species
ecosystems. Ecosystem-based approaches will increas-      (Pauly et al. 2002), and ‘collateral impacts’ in the form
ingly be viewed as a mechanism for resolving conflict-     of unwanted by-catch and habitat degradation by
ing objectives arising from the species-by-species ap-     mobile gears (Chuenpagdee et al. 2003). Until recently,
proach, and for integration of knowledge from biology,     such effects, sometimes likened to using large-scale
oceanography, economics and other social sciences,       forest clear-cutting in the pursuit of an industrial-scale
law and politics.                        deer hunt (Watling & Norse 1998, Pauly et al. 2002),
 Moving from ’intelligent tinkering’ to a more direct     were not accounted for in assessments and manage-
focus on ecosystem properties and outcomes will neces-     ment, nor perceived by the public as having important
sarily involve closer ties between science and manage-     impacts on ecosystems. In essence, fisheries are actively
ment. Working in concert, science and management        undermining the resource base underlying their pro-
need to recognize and incorporate fundamental uncer-      ductive capacity — directly through excessive removals,
tainties in how biological components are linked and to     and indirectly through ecosystem modification.
utilize adaptive strategies intended to delineate be-       The notion of ‘freedom of the seas’, introduced to the
                                ‘western’ world by Hugo Grotius as Mare Liberum,
tween plausible alternatives. In all likelihood, incorpo-
rating ecosystem-based approaches will mean that        has dominated humanity’s approach to ocean use for
                                nearly 400 yr (Russ & Zeller 2003). Historically, Mare
more factors must be explicitly accounted for in man-
                                Liberum was intended as freedom of navigation and
agement, which will require greater evaluation of
potentially conflicting objectives (Sainsbury & Sumaila     trade during maritime conflicts between 17th century
2003). We agree with other reports concluding that the     England and Continental Europe, yet over time was
EAF should generally result in more conservative man-      also increasingly interpreted as a ‘right to fish’ (Russ &
agement than would be the case under more traditional      Zeller 2003). It is this perceived ‘right’ which, in con-
paradigms (e.g. NRC 1999b, Anonymous 2000, Hall         junction with modern market economics and taxpayer
1999, Murawski 2000, Sissenwine & Mace 2003). The        subsidies, has led to resource over-exploitation (Pauly
primary benefit of an EAF is that it offers a more -      et al. 2002). Until the late 20th century, much of the
complete and integrated accounting of the full range      world’s oceans were freely accessible to anyone want-
benefits and costs to society associated with developing    ing to fish. However, given that the majority of marine
sustainable approaches for living marine resources.       catches are taken within 200 nm of coasts (Jennings et
                                al. 2001), one would have assumed that the potential
                                for overfishing would have declined with the introduc-
The future of fisheries: from ‘exclusive’            tion of national responsibility via 200 nm Exclusive
                                Economic Zones (EEZ). Yet, traditional approaches to
resource policy to ‘inclusive’ public
                                setting and implementing management policy, based
         policy                     primarily on target species considerations (ignoring
        Dirk Zeller, Daniel Pauly            ecosystem effects), have failed to prevent stock de-
                                clines, collapses and fisheries closures.
   Fisheries Centre, University of British Columbia,
                                  The way forward. The debate on how to deal with
   2259 Lower Mall, Vancouver V6T 1Z4, Canada
                                the specifics of overfishing is ongoing. Yet, the solu-
 Emails: d.zeller@fisheries.ubc.ca, d.pauly@fisheries.ubc.ca
                                tions are obvious.
 The current state of global fisheries. The reality of      (1) Drastically reduce effort and capacity. Many fish-
global overfishing is now well documented (e.g. Watson     eries today suffer from significant overcapacity, with
& Pauly 2001a, Pauly et al. 2002, Christensen et al.      values of 30 to 50% estimated by Garcia & de Leiva
296                    Mar Ecol Prog Ser 274: 269–303, 2004




Moreno (2003), and even higher values suggested by,      nant political role played, during management and
for example, Pauly et al. (2002). Economists argue that    catch allocation debates, by the users of the resource
capacity reductions are best achieved through reduc-     (i.e. the fishing industry, explicitly seen as ‘client’ by
tions of subsidies, and warn that even subsidies used     regulatory agencies) versus the true owners, the pre-
for vessel decommissioning schemes can be negative      sent and future citizens of those countries whose stocks
in their impacts (Munro & Sumaila 2002).           are being fished (Macinko & Bromley 2002). Moreover,
  (2) While technology usually cannot be ‘dis-invented’,   our heavy reliance on the concept of ‘sustainability’,
we can mitigate some of the negative effects of the      which is often the legally enshrined goal of fisheries
growth in technological capacity and fishing ability by    management, should be re-examined. Most optimisti-
removing a substantial fraction of all habitats from     cally, this concept implies maintenance of resource
fishing. Thus, we can artificially recreate the natural    biomasses at current levels, usually much below any
refuges which are now lost to ecosystems, and which      levels optimizing productive potential. More pessimisti-
previously provided the key element of their apparent     cally, it implies a continuous erosion of the resource
sustainability (e.g. Pauly et al. 2002, Russ & Zeller     base (Pauly & Zeller 2003). Hence, we need to consider
2003). While debate continues on the optimal size and     ‘ecosystem rebuilding’, rather than ‘sustainability’, as a
location of no-take zones, a growing consensus points     default policy goal (Pitcher 2001).
towards extensive networks of protected areas of at       In the long term, the changes called for above can
least 20 to 30% of each habitat (e.g. IUCN 2003). Note    only come about if the often politically ‘exclusive’
that benefits of no-take areas extend well beyond       resource policy structure is altered to an ‘inclusive’
those indicated here, both with regards to fisheries as    public policy with active participation by all stakehold-
well as non-extractive uses (genetic- and bio-diversity    ers, including extractive and non-extractive interests.
protection, bio-prospecting etc.). In essence, large-     However, by default, overriding precautionary consid-
scale no-take zones are a precautionary ecosystem-      eration must be given to the long-term interests of
based management tool par excellence (e.g. Walters      future generations. This implies the need for economic
1998, Roberts et al. 2001). It is well recognised, and    discounting practises that consider intergenerational
implicitly understood, that the establishment of such     equity, which accounts for the economic benefits of
networks has to go hand in hand with overcapacity       conserving resources (Sumaila & Walters 2004). Cen-
reductions, in order to avoid effort build-up in the     tral to this shift is the realisation that fishing is a ‘privi-
areas still open to fishing.                 lege’ granted to fishers by society. Thus, fishing is not
  (3) To address ‘collateral impacts’, we have to recon-   a ‘right’ in the enforceable sense normally accorded to
sider gear types and their use within an ecosystem      this word (see Macinko & Bromley 2002). However,
framework, rather than target species issues alone.      given that ‘carrots’ work better than ‘sticks’, we
Technological improvements (e.g. bycatch reduction      argue — as do others (e.g. Hilborn et al. 2003) — that
devices), and selective targeting of fishing grounds to    positive incentives in an ‘inclusive’ public policy and
reduce bycatch, are helpful in the short term, but not    governance framework are essential.
sufficient in the long run. This applies especially to      Unlike any other industrial-scale economic activity
more unselective mobile bottom gears, especially bot-     that humanity engages in, fishing is embedded in the
tom trawls (Watling & Norse 1998, Chuenpagdee et al.     high and inescapable uncertainty underlying natural
2003). The continued use of gears that inflict ‘collateral  marine systems, and our ability to understand and pre-
impacts’ also highlights the need for extensive net-     dict them (e.g. Walters 1998). Often ignored is the fact
works of no-take areas and use-specific ocean zoning     that fishing is not an agricultural activity, but rather the
to mitigate these effects at an ecosystem scale (Chuen-    only industrial-scale form of hunting wildlife, which
pagdee et al. 2003, Russ & Zeller 2003).           has important (but mostly ignored) consequences for
  Science, management and inclusive public policy. If    management. Foremost, it requires a precautionary
we are serious about implementing strategic solutions     approach and, as an expression of society’s ownership,
such as those outlined above, and hence move from the     the predominance of the public in policy debate.
traditional focus on single-species to a precautionary    Indeed, reclaiming the ocean and its resources from
ecosystem-based management, a fundamental shift in      excessive use will be a key task for humanity in the
the governance of ocean resources will have to take      21st century. This requires that information on the
place (Pauly et al. 2002, Russ & Zeller 2003). In the gov-  state of marine ecosystems and resources be widely
ernance context, the deeper problem underpinning the     available, and in a form accessible to the lay public.
fisheries crisis is neither a failure of science (despite    Information access and distribution. ‘Wissen ist
the often used excuse provided by ‘uncertainty’), nor     Macht’ (knowledge is power) is as crucial today as it
one of management; rather it is a problem of public      was in the late 19th century when it was a rallying cry
policy (Pauly & Zeller 2003). This relates to the domi-    for political engagement in Germany (von Rüden &
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           Theme Section: Ecosystem-based approaches to management of marine resources




Koszyk 1979). Examples also abound of the natural sci-   fisheries landings data (1950–present), and facilitates
ences being perceived as empowering, notably in Vic-    the development of complementary data series and
torian England, where scientists such as T. H. Huxley    approaches. Findings from the project are rooted in
regularly conveyed scientific insights to working class   peer-reviewed outputs to ensure scientific account-
audiences (Desmond 1997). Public knowledge and the     ability. However, emphasis is also placed on present-
empowerment it bestows are particularly critical today,   ing, via the web, public-oriented information on the
when we are witnessing some of the most extensive,     effects of fishing on ecosystems at a large spatio-
and threatening, human induced changes to global      temporal scale, through conceptually clear and graph-
ecosystems. Informing the true owners of marine       ically compelling presentations. Importance is placed
resources, i.e. the public, and the law makers that rep-  on being as jargon-free as possible, e.g. through the
resent them, about the impact of fisheries on ocean     use of common names. Time series of fisheries catches
‘health’ is often difficult. A strong lobby exists which,  extracted from the waters now encompassed within
similar to the Tobacco Institute with regard to the     the EEZ of a given country can be viewed by common
effects of smoking, challenges the obvious to maintain   or scientific names, or by countries fishing within these
the unacceptable (Pauly & Zeller 2003). This, in turn,   waters based on a fishing access agreement database
requires that knowledge and information are transpar-    that is also accessible. Additional outputs include ani-
ent, accessible, freely available and compelling. Only   mated catch, biomass and primary productivity maps
then can an informed public engage in the decision     that are visually compelling and easily understood
making process as the major stakeholder with respect    (Watson et al. 2003), and soon will include economic
to their resources. This would ultimately lead to a     outputs, notably catch value. Underlying data sources
modern form of community control, the contemporary     and background information are readily accessible, in-
equivalent of historical practises in, for example, parts  cluded via links to associated databases. Outputs from
of the Pacific (e.g. Johannes 1978). An example of the   this project have already yielded important results
potential for success in such an approach is the com-    (e.g. Watson & Pauly 2001b, Pauly et al. 2002, Chris-
pelling case of Rachel Carson’s Silent Spring which,    tensen et al. 2003, Pauly & Maclean 2003), including,
via its public impact, affected policy on pesticide use   for example, the FAO itself acknowledging the prob-
(Carson 1962). A step in this direction with regard to   lem of reliability of fisheries statistics reported to it by
the effects of fisheries is attempted in Pauly & Maclean  member countries. This has lead to a revision of global
(2003).                           fisheries catches, identifying a downward trend in per
  The growing scientific knowledge on the effects of    capita food supply (see www.fao.org/fi/statist/nature_
fishing on marine ecosystems needs to be made avail-    china/30jan02.asp). The public and media attention
able in outlets other than the peer-reviewed specialist   attracted by the ‘compelling and easily understood
literature or government reports, neither of which are   maps’ (Hall 2004) accompanying much of the project
easily accessible for public scrutiny. This information   output has the potential to feed directly into the policy
should be synthesized and presented in a readily      debate called for above.
understood form, and not shrouded in technical jargon.     However, besides being anchored in peer-reviewed
Such public outreach must become part of our work,     literature, this knowledge must also be made available
whether we engage in it directly or indirectly, with the  offline, i.e. in general interest scientific/nature maga-
help of the communication professionals available at    zines (e.g. Watson & Pauly 2001a, Pauly & Watson
many research institutions. And given today’s wired     2003). These, and other contributions using such media
world, one of the best media for dissemination of such   (e.g. Safina 1995) and the general press (e.g. Broad &
information is the World-Wide-Web.             Revkin 2003) have increased interest by the public
  There are few examples of web-based vehicles for     in marine ecosystems and fisheries issues, and are
the presentation and dissemination of scientific knowl-   encouraging. Clearly, as ‘seekers of knowledge’,
edge. The web sites of most research groups empha-     scientists should feel compelled to contribute the re-
size only their existence and describe the minutiae of   sults of their investigations in a manner accessible to
their activities. However, the Sea Around Us project at   all of society.
the University of British Columbia Fisheries Centre      Biodiversity databases as information systems. Other
aims to provide an integrated analysis of the large-    examples of the usefulness of online knowledge dis-
scale impacts of fisheries on marine ecosystems, and    semination relate to the growing need for public
encourages direct information and data-accessibility    understanding of biodiversity issues. For example, Fish
through its data-oriented front-end web-structure (see   Base (Froese & Pauly 2000, see www.fishbase.org),
www.seaaroundus.org). The project utilizes large-      presents key nomenclatural, distributional, biological
scale time series datasets, such as the United Nations   and other information for all the over 28 000 extant
Food and Agriculture Organization (FAO) global       species of finfish. It is maintained by a team of special-
298                    Mar Ecol Prog Ser 274: 269–303, 2004




ists who extract and standardize data from scientific     resources are increasingly exploited by distant-water
publications. FishBase encourages contributions from     fleets from developed countries, with little economic or
the scientific community, in close collaboration with a    food-security returns (Kaczynski & Fluharty 2002).
global network of experts on various taxa and topics. It     With regards to fisheries and the need for ecosystem-
also provides access to more than 1.5 million records in   based management, the existence of overfishing is not
over 30 other distributed databases, and acts as an      disputed by the scientific community (as mentioned
electronic archive for historical datasets. FishBase now   earlier), although specific aspects of the problem might
receives over 10 million hits per month from a wide      be argued about as part of normal scientific debate
variety of users from all over the world, thus demon-     (Hilborn et al. 2003). The real problem is not the tech-
strating beyond doubt that there is substantial public    nical quibble over the magnitude of decline in a stock
interest in scientific information if it is presented in a  or degradation of ecosystems, but rather the more fun-
user friendly manner.                     damental problem of fisheries being a force exerting
  However, ecosystems and fisheries are not com-       pressure on stocks and disturbing ecosystems, all with
prised only of fishes. Hence, other taxonomic groups     little or no ‘counter-weight’. The recent trend towards
and data-sources also need to be considered, e.g.       evaluating fisheries in a conservation context, such as
through joint initiatives such as the standardization     the growing influence of endangered species legisla-
and cross-linking of existing databases, as now        tion and non-extractive interests in fisheries manage-
achieved by linking the Sea Around Us database        ment, are examples of ‘counter-weights’ that may lead
with the cephalopod database CephBase (see www.        to more precaution and balance.
cephbase.org). Alternatively, new biodiversity data       Putting fisheries in their ecosystem context. No one
sources need to be created, such as the Scientific Expe-   seriously argues that ecosystem-based management
ditions Database being developed by M. L. D. Palo-      is about abandoning traditional single-species stock
mares, parts of which are currently accessible through    assessments. Indeed, most modeling approaches pro-
FishBase. Such historic information, together with      viding ecosystem-based information for improving
long-term data sets as derived from surveys (e.g.       fisheries management and re-building ecosystems rely
http://ram.biology.dal.ca/~myers/welcome.html), pro-     on single-species assessments as a sizeable part of
vide crucial historical baselines to inform public policy   their input data (e.g. Christensen et al. 2003). Nor is
debate. Such information also counters the ‘shifting     ecosystem-based management only about thought-
baseline syndrome’ (Pauly 1995), which describes       lessly setting up no-take marine reserves, leading to
humanity’s general inability to fully understand the     the common accusation that all this would do is con-
changes our actions have caused, once these changes      centrate the same fishing effort into the remaining,
are outside the observers generational memory. This      reduced fishing areas (Hilborn 2003). Such oversimpli-
implies that we do not readily appreciate what ecosys-    fied arguments completely miss the major point of the
tems were like on timelines outside of our personal      solutions offered by proponents of ecosystem-based
experience.                          management. Put simply, the point is that the various
  Dealing with denial. Debate and critical evaluation    factors act in combination, and need to be addressed as
of scientific investigations are an integral and valuable   such — combined — and, hence, ecosystem based. To
part of science, leading to improved insights into nat-    achieve this requires a truly ‘inclusive’ public policy
ural processes and contributing to scientific consensus.   environment, leading to better governance of these
As mentioned above, the real problems arise from       public resources (i.e. the ecosystems) than is currently
denying the obvious in order to maintain a status quo     the case with most fisheries around the globe.
that benefits only a few. The most obvious recent
example is that of B. Lomborg, whose self-serving
                               Acknowledgements. We thank our colleagues of the Sea
argumentation about an environmental ‘litany’ in the     Around Us Project for discussions and comments. We ac-
Skeptical Environmentalist (Lomborg 2001) has been      knowledge the support of The Pew Charitable Trusts, Phila-
shown, by recognised experts in their field (see e.g.     delphia, for initiating and funding the Sea Around Us Project.
Grubb 2001, Pimm & Harvey 2001), to be a misleading,
superficial treatment of environmental issues, founded
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