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On the mismatch of scales in EBM

by the NCEAS-EBM Journal Club

Target Journal—TREE, Ecology & Society?

Many of the worlds' marine ecosystems are severely degraded (Myers & Worm, Jackson et al., REFS), and only recently has broad attention and political will focused on trying to prevent further damage or to reverse the damage already done. Stricter fishing regulations (including area closures), greater awareness of the impact of land-based activities such as agricultural run-off on ocean ecosystems, establishment of marine protected areas and no-take reserves, and heightened attention to the effects of climate change on marine systems have all emerged as approaches and relevant issues for improved management of the oceans. In recognition of the complexity of the ecological and social systems that are relevant to management decisions and plans, and the key role that humans play in both positively and negatively affecting natural systems, there has been a surge of interest in ecosystem-based approaches to the management of natural resources (Oceans Act, Pew Report, Ocean Commission Report). Ecosystem-Based Management (EBM) attempts to integrate information from scholars, politicians, managers and stakeholders—people from very different fields and backgrounds—in order to develop more effective and holistic environmental management strategies.

Despite decades of research on related concepts (sustainability [REFS], ecosystem management [REFS], and more recently ecosystem-based management [REFS]), implementations of EBM initiatives are still in their infancy and no “recipes” for EBM exist. However, common to all definitions and discussions of EBM is the idea that the scale of different process, and the challenge of matching scales (or at least reconciling differences), is fundamental to the sustainable governance of the oceans (Constanza et al. 1998, REFS). Scale-matching requires that decision-making be assigned to institutional levels that maximize the input of ecological and stakeholder information at the scale(s) relevant to the jurisdiction of the institutions and the ecological and social processes managed by that jurisdiction. Once the information is assimilated at the appropriate scale, it can then be propagated across institutional levels (Costanza et al. 1998). When scale-matching is done successfully, institutions should be able to internalize the full costs and benefits of the ecological and social decisions they must make, more effectively integrate information across scale boundaries, and respond more quickly and efficiently to environmental challenges since the scale of the system feedback and institutional response are similar. In practice, the implementation of scale-matching has been identified as one of the most challenging aspects in the implementation of EBM.

Scale can be a hard concept for institutions to grasp, or at least to reconcile; different levels of organization perceive scales differently. Ecological, social, political, and economic systems all have their own characteristic spatial and temporal scales, as do the organizations in charge of understanding or management these systems. Imagine a group of experts working in the EBM of a coastal fishery. Their primary task would be to outline the dominant process regulating the fishery. The biologist would be concerned with processes such as the time to reproductive maturity among the species in the fishery, population connectivity, and the length of coastline over which they are distributed, a matter of several months to years and tens to hundreds of km. A stakeholder, say a fisherman or a recreational operator, would be concerned with time spent at sea and the length of the fishing bouts, perhaps days and tens of km. Meanwhile, a lawmaker may be interested in the temporal and spatial extent of typical regulatory initiatives and the politics behind creating such initiatives, which likely track election cycles (2-6 years) or budget cycles (annual) and are focused on the scale of the electoral district (city [kms] to national [1000s of kms]). An economist, who is tasked with documenting or predicting the consequences of different management decisions, may focus on infrastructure investment such as boats or processing plants, which have a lifespan of decades and service an area of tens to hundreds of kms, as well as daily expenses and profits derived from single boat trips and the sale of harvest to consumer (local to global scale, depending on the fishery). The length of the spatial and temporal scales that concern the biologist, the stakeholders, the politician, and the economist share little or no overlap: there is a mismatch of scales.

A key roadblock to EBM arises from the lack of overlap between scales as participants share no common ground for sharing information. The ecological and stakeholder information is relevant and useful only when institutions are able to assimilate it. And the focus of lawmakers and managers on spatiotemporal scales decades and thousands of km means that they are unable to craft management actions that can track the fine scale spatial and temporal heterogeneity in both the biology and the activities of stakeholders.

Ecologists and oceanographers have spent decades focused on the role spatial and temporal scale can play in affecting both how natural systems work and our perceptions of how they work (Levin REF). The Long-Term Ecological Research (LTER) program was established to help overcome the temporal limitations of most ecological studies (typically <3yrs), and recent collaborative initiatives have helped expand spatial scales of sampling efforts and experiments (such as PISCO, others??; most ecological studies are confined to 1m2 plots). These and other efforts have helped expand the experimental frame of reference and uncovered key links between local, regional, and global processes. The discovery of El Nino and Decadal Oscillations, and the affects of these large-scale climate processes on local and regional ecology and oceanography, is a classic example of this insight gained by focusing on the scale of processes and how they interact (REFS). It is at these particular scales where the majority of ecological and physical processes relevant for EBM take place (Wilson 2005). In contrast, little work has been done to apply the concept of scale to governance, economic, or social systems, and even less work evaluating how the scales of these systems may or may not interact. Hence, the objective of this study is to introduce a framework for comparing the scales at which these difference systems act and make a preliminary attempt to quantify the mismatch of scales in EBM in order to define critical areas where more coordination and perhaps a shift in scale for one or more systems needs to occur.

The Stommel diagram

The physical sciences have long-recognized that processes have spatial and temporal scales, and in the 1960's Stommel (1963) developed a framework for describing and quantifying these scales that allows for simple visualization of these scales (Fig. 1). Stommel's focus was on the joint space-time distribution of water movement in the oceans in the context of characterizing variations of sea-level height, but the approach and concept has been used for a variety of purposes. The notion behind a Stommel diagram is that processes that take place over specific spatial scales that in turn take place over specific temporal scales. In the case of diurnal tides, these scales are meters and hours, while a Tsunami takes place over hundreds of meters and minutes and glacial variations over thousands of meters and centuries (Stommel 1963). As Stommel diagrams are intended to accommodate large scales of variation, the x and y-axis are usually in logarithmic rather than the usual linear scale. In the context of the hypothetical group of experts described above, the mismatch of scales can be examined through a Stommel diagram, as in Fig. 2 (TO BE DONE). The four spatial and temporal domains as we describe then in the text have been plotted [a Figure with several bubbles] and are described in greater detail below. Our effort and intention here is primarily conceptual, such that the exact scales of each system (i.e. location of the Stommel bubbles) require further investigation.

Ecological and geophysical scales

Some of the most influential examples of Stommel diagrams in the biological and oceanographic literature document the variations in zooplankton biomass (e.g. Haury 1978). Zooplankton dynamics, it turns out, exhibit scales that are largely confined below a decade and hundreds of km, although variability over longer scales was not considered. This explicit depiction of scales of variation has repeatedly been used to exemplify and illustrate complex problems in ecology and fluid dynamics where specifying the space-time scale is key to the description of the problem under study (Levin 1992), although there is an even larger literature on the effects of scale on these systems that does not employ Stommel diagrams—this is not a problem, but instead an opportunity to develop a synthetic ecological Stommel diagram.

[case study example]

Stakeholder scales

As with ecological and physical systems, human systems also have characteristic scales that depend on the activity in question. Fishermen, recreational divers, beach-goers, coastal developers, and farmers, for example, all have typical temporal and spatial scales at which they interact with the ocean. Fishermen tend to think and behave in months (fishing seasons) and tens to hundreds of kms (range of fishing trips), while beach-goers tend to think in days (vacation time) and a few kms (favorite beaches). Interestingly, as agrobusinesses and fishing companies consolidate, the scales at which these activities act has increased significantly, serving as a reminder that the temporal and spatial scales of stakeholder groups, in particular, are not static.

[case study example]

Governance scales

The idea of scale is less often addressed explicitly with governance activities, although these scales clearly exist. Every agency has a jurisdiction (spatial scale), every law has both spatial (city, state, national) and temporal (indefinite, sunset clause, etc.) scales, as does every politician (representative district and election cycle). These scales can have profound consequences for how government and the laws it creates and enforces respond to and interact with (or don't) natural and human systems. The tension between State and Federal rights in the U.S. is a classic example of matching (or mis-matching) regulatory oversight with stakholder behavior and ecological processes. Defining these governance scales precisely, however, is not a trivial matter. Laws and regulations may address a large jurisdictional scale, but the scale of the management actions within the law may be of finer scale and more variable. For example, the Sustainable Fisheries Act gives jurisdiction to the NMFS and the PFMC for waters in the EEZ and to the DFG for state waters, but specific actions within the law may focus on particular gear restrictions at some locations, MPAs at other locations, and water quality regulations that affect some areas but not others. What is the spatial scale of this Act, then?

Focus on the scale of the policy levers??, i.e. over what spatial and temporal scales can the managers effect change? So in a fisheries example, it'll be fishing seasons, MPA sizes, lengths of other time-area closures, size of overall jurisdictional areas, etc.

[case study example]

Economic scales

[case study example]

Scales among services

We have focused so far on describing and matching the scales of the systems that produce a single ecosystem service (or management goal) and how there tends to be a mismatch in how different systems (people) view and understand these scales. This mismatch problem becomes even more complex when multiple ecosystem services are included. For example, the Elkhorn Slough EBM project aims to address issues of water quality within the slough, which is affected by the dynamics of agricultural production and land use over a large area, as well as tidal erosion problems within the slough that are very local and will likely be ameliorated by rather small scale restoration efforts (re-engineering the size of the tidal mouth, adding sediment to wetlands, etc.). In other words, ecosystem services will each have their own scales, generally defined by the people requiring those services, creating a potential fifth “bubble” in the Stommel diagram.


  • Challenge of matching scales of information to scales of decisions, across systems.

  • When scales are matched, information flow and speed and effectiveness of management decisions can be optimized.


  • It's clear there are examples of the scale mismatch resulting in ecological failures, but can we also highlight particular examples where the mismatch in scales results in a market failure? (maybe in an idealized social-ecological system they are one in the same). Being able to show that we miss out on economic opportunities by not properly coupling the management and ecosystem scales would be a pretty powerful argument for ebm.


by Benjamin Halpern last modified 30-05-2006 12:56

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