Findings and Recommendations
Challenges in assessing and responding to the ecosystem effects of fishing include gauging the magnitude, spatial extent, and mechanisms of change in marine food webs. Identifying and understanding these potential impacts and interactions will be essential for developing future management actions. However, better scientific understanding is not enough. Stewardship of the marine environment will demand difficult societal choices and tradeoffs between uses, because resources are connected through food-web and ecosystem interactions; maximizing each individual harvest or use may be impossible as the upper limit of available productivity is reached.
Science has revealed numerous ecosystem-level effects of fishing in marine ecosystems. There is conclusive evidence that stock biomass and abundance have been reduced by fishing. And while the exact magnitude of depletion for particular stocks is often debatable, few would argue that there is no need for actions to protect against continued declines in some cases. Changes in size structure and genetic composition, localized depletions, and alterations in trophic structure of ecosystems are all occurring as well. However, effects of fishing are spatially heterogeneous and generalizations from one region or fishery to global fisheries can be misleading.
The evidence provided in Chapter 2 is compelling, but by no means exhaustive, concerning all possible effects. Ongoing research and assessment is required to understand the temporal and spatial extent of fishing impacts and how current and future management policies act to ameliorate or worsen the effects of fishing on marine food webs and species interactions.
Fisheries management strategies currently employed in the United States generally do not take into account ecosystem effects and multi-species interactions. Ecosystem considerations are discussed in regular stock assessments, but in general they do not involve a comprehensive evaluation of management strategies. Also, environmental impact statements are required for major fishery management actions, but there is no regulatory requirement to account for interactions among species. Instead, harvest policies tend to focus almost exclusively on single species, and maximum sustainable yield reference points are the norm.
In a multi-species context, interaction between species, mediated through predator-prey interactions and food-web effects, will need to be explicitly considered when deciding harvest strategies. For examples, if interacting species are both targeted for harvest, maximizing yield for each will likely be impossible. Tradeoffs between the allowable catch of each species will need to be made, and the desired level for each species’ harvest decided simultaneously. This must occur while avoiding possible undesirable and irreversible shifts in the composition of the overall ecosystem. In addition, fisheries are not the only service that humans derive from the ocean, and incorporating these values into fisheries management decisions further increases the apparent number of tradeoffs.
Protecting ecosystem functioning and making allocation decisions between uses are two distinct—yet interdependent—issues that managers will have to face with increasing frequency as ecosystem considerations are factored into fisheries management. Within a functioning ecosystem, differing harvest and protection goals can be established amidst a variety of stewardship options and tradeoffs between uses. Greater understanding of these tradeoffs and the consequences of management actions are needed, but ultimately, society will need to decide the desired balance of services provided by the ocean and what protections to afford marine species. Based on these decisions, management approaches will need to be crafted to increase the chances that harvest controls are implemented effectively and in a manner that might further ecosystem considerations among users.
The following recommendations fall into three categories: (1) implementing ecosystem considerations in fisheries management actions, (2) promoting stewardship, and (3) supporting future research.
Applying a Food-Web Perspective to Fishery Management Strategies
Multiple-species harvest strategies should be evaluated to account for species interactions and food-web dynamics.
Setting multi-species harvest strategies requires taking into account food-web interactions, changes in trophic structure, life history strategies, and bycatch,
all of which can change ecosystem productivity. If management is to account for the ecological interdependence among harvest targets and other food-web components, methods will be needed for quantitatively and qualitatively examining these interactions. Increased application of existing food-web, species-interaction, and ecosystem models, and development of new ones, can improve understanding of food-web effects and the impacts of fishing on ecosystem components, and also help to develop multi-species harvest strategies.
Food-web, species-interaction, and ecosystem models should be used to evaluate alternative policy and management scenarios. These scenarios should elucidate the management tradeoffs that need to be made among user communities in a multi-species context and thereby inform the choice of multi-species harvest strategies.
Fisheries management advice has tended to follow prescriptive policies defined in terms of generic biological reference points for individual populations as called for by the Magnuson-Stevens Fisheries Conservation and Management Act. However, within an ecosystem context, tradeoffs between conflicting management objectives should be made explicitly by evaluating consequences in terms of different measures of performance that reflect impacts of policy decisions on varied ecosystem components and uses. These tradeoffs will not only need to be made between competing fisheries, but should also account for the interactions of fisheries with other consumptive and nonconsumptive uses.
Although the availability of data required to build food-web models is generally limited, enough information exists for many systems to begin the development of new models now—these models should continue to improve based on new studies and information. The goal should not be to build a single best model, but to build a series of models as alternative hypotheses of what may happen, each representing a plausible scenario. Different fishery management strategies could be tested across the series of scenarios and the outcomes examined. Initially, analyses could be directed at near-term decision making by testing how current policies perform in an ecosystem context. Assigning relative likelihoods to each scenario will allow for tradeoffs between conflicting management objectives to be evaluated in order to better inform decision making. Therefore, model-based scenario analysis will encompass more than just determining reference points to be used as targets and limits. By choosing a particular management strategy, the feedback rules needed to calculate input- or output-based fishing controls will also be determined and the data needed to implement those rules will be specified.
Such approaches should be conceived as adaptive management experiments, with a requirement to implement monitoring programs to evaluate system responses and to detect unexpected consequences, should they happen. Scenario analysis will be best applied in an iterative manner and should continually incorporate new knowledge of the system as measured by outcomes of previous
management actions (Figure 6.1). Model-based scenario analysis should first be applied in ecosystems that are relatively well known scientifically. Once a framework for scenario-based decision making has been established, scenario analysis can then be applied in ecosystems and fisheries that are potentially more contentious due to the tradeoffs that need to be made.
Interdisciplinary working groups should be considered as a mechanism for developing appropriate models for each management area and for generating the series of scenarios needed to test proposed management actions.
Building ecosystem models to design harvesting policies requires the cooperation of many specialists and the integration of information from many sources. To promote the development of ecosystem models for use in policy analysis, ecosystem-specific working groups could be established for particular areas of concern—composed of scientists and modelers drawn from the management agencies and academia, and representing both natural and social sciences.
Working groups would facilitate the consolidation of existing information, the generation of new syntheses with existing models, and the development of new models and other approaches to inform scenario development and forecasting under alternative management strategies. Working groups could meet with a variety of stakeholders—including fishermen and other consumptive and nonconsumptive users—to identify important tradeoffs that should be considered when creating models and to evaluate feasible candidate policies. In particular, fishermen’s historical knowledge of the resource and results of previous management actions may be an extremely valuable resource. The simulations created should be quantitative when possible, but even rigorous qualitative scenarios would be useful in some systems. Analyses and models generated by working groups should be made publicly available and be published in the peer-reviewed literature. Iterative analyses might be incorporated as the systems begin to respond to management actions.
New governance and management instruments that create stewardship incentives among user groups should be evaluated and considered for adoption in the United States for multi-species fisheries management.
Fisheries management has largely utilized a top-down system that places managers and users in an adversarial relationship that sometimes generates rash “race-to-fish” incentives among fishermen. But new and fundamentally different schemes adopted for some U.S. and international fisheries alter incentives and redirect fishing behavior in essential ways. All of these schemes use some form of dedicated access privilege, whereby consumptive users are granted secure shares in biologically determined allowable harvest targets. Previous reports indicate that secure access privileges provide new incentives to create value
rather than to maximize harvest, and they may also generate a stakeholder interest in the long-term health of the resource.
Fisheries governance and ecosystem management options used by countries other than the United States and a few fisheries within the United States can be compared and examined for broader application in U.S. fisheries (nationwide). There are a number of specific governance options, each of which convey secure access privileges, including individual transferable quotas (ITQs), cooperative harvesting associations, and territorial harvesting institutions. Furthermore, many systems have begun to address ecosystem management issues such as bycatch reduction, habitat damages, marine reserve site selection, and nonconsumptive services. In some countries, there is a considerable history of experience that would allow for the assessment of strengths and weaknesses of these options in different biological and socioeconomic settings. There is also much to be learned from the few systems that have been established in the United States (i.e., sablefish/halibut individual fishing quota [IFQ] system), both from their successes and previous failures.
Promoting Better Stewardship of the Marine Environment
Fisheries management structures should ensure that a broad spectrum of social values is included in policy and management decisions.
As previously recommended, ecosystem-based fisheries management approaches should be determined using model-based scenario analysis. However, this will not be a productive exercise if those affected by alternative outcomes are not involved in the decision-making process. Furthermore, proper stewardship of the marine environment requires consideration of values beyond just the commercial value of harvested species. Incorporating such values will require input both from fisheries scientists and social scientists—especially because fisheries management is about managing people and their behaviors as well as the biological resource itself.
To produce comprehensive management plans, fisheries managers should incorporate the best available social science as well as the best available natural science in their deliberations. The main objective should be to make better-informed decisions about tradeoffs across sectors and with other services. In other words, while natural science is essential for management, natural science by itself is not enough; proper management requires consideration for marine organisms as well as for human behavior and values. This will require greater involvement by social scientists with expertise in fields such as valuation, natural resource economics, decision science, and institutional design.
Governance structures should also be examined to ensure integral and effective representation of the public in deciding resource allocation tradeoffs. One of the principal goals of the Magnuson-Stevens Fishery Conservation and Manage-
ment Act was to link the fishing community more directly to the management process. It has succeeded in that commercial and recreational fisheries are represented through the current organization of the Fisheries Management Councils, but nonconsumptive services and existence values are most certainly underrepresented. If model-based scenario analysis is used for making fisheries management decisions, nonconsumptive and public-good values will need to receive proper consideration when making tradeoffs among ocean services. Creating a mechanism for input for these other users could be accomplished at several stages of the management process, and NMFS and the Fishery Management Councils should continue to examine new avenues for greater stakeholder participation.
Increasing Understanding of the Ecosystem Effects of Fishing
Research is needed that improves understanding about the extent of fishing effects on marine ecosystems and promotes the development of ecosystem, food-web, and species-interaction models and their incorporation into management decisions.
Data needs in support of ecosystem-based management will likely be more than the simple sum of currently available single-species information. Much more can be known about food-web linkages and interactions, including the strength of linkages between species and life-history stages and how these interactions change over time. In addition, modification of existing models and/or the development of new models are needed to better account for uncertainty in model output, to elucidate indicators of regime shifts and other interacting factors, and to evaluate monitoring schemes necessary to provide adequate information on ecosystem structure and function. To improve the utility of current models and their application to managed ecosystems, research should be conducted to provide a better understanding of:
the dynamics of food-web interactions, including food habit data and interactions at lower trophic levels,
per capita effects or population effects so that dynamical changes at a variety of trophic levels can be evaluated,
whether models possibly ignore species with strong interactions in the ecosystem, and
the need for baseline data on a number of non-target and lower-trophic species to determine the role of these species in the ecosystem when their abundances and interactions change due to fishing pressure.
Spatially explicit biological data should be collected that will allow both large-scale population trends and changes at finer scales to be monitored and understood. Patterns of interaction and the strength of these interactions vary in time
and space. Collecting data on both temporal and spatial scales will allow for the variability in these interactions in both dimensions to be examined, thus improving the use of models to generate future scenarios. This may also lead to management approaches that can take into account temporal and spatial fluctuations in species interactions, biomass, and life history.
Research is also needed to determine whether interactions at various scales can help to define ecosystem boundaries in a new way. Biologically relevant boundaries in the marine environment are virtually impossible to identify, making it difficult to set the boundaries for modeling and management. Examining population trends and species interactions on finer spatial scales may help to define important biological interactions, which can then be bounded by management goals, financial constraints, and other realities imposed by political considerations.
Historical data assessments will be necessary to provide new insights about past species abundances and interactions. Comprehensive analyses of existing data can be applied to ongoing changes in target species, and they can help identify changes in habitat and non-target species that are thought to indicate ecosystem status. Landings data, narratives and descriptions, fisheries-independent data, phytoplankton and plankton records, satellite data, and archived specimens should all be considered when conducting these types of analyses. Examining these time-series or snapshot data in ecosystem and food-web models may provide the best approach to synthesizing long-term data and identifying alternative future scenarios to evaluate policy choices. Determining historical levels of exploited populations, and their natural fluctuations, should also provide a baseline around which to establish future management actions, including the setting of recovery goals.
Research is needed that expands relevant social and economic information and the integration of this knowledge in fisheries management actions.
Future research should measure and evaluate nonconsumptive uses of marine ecosystem services and quantify the non-use values of marine ecosystem components. Research is also needed to determine if (and how) social and economic principles vary from ecosystem to ecosystem. Concepts from decision science and financial portfolio theory are well developed and can be used to inform decisions in other settings such as in discussions of multi-species ecosyste objectives.
Understanding the social and ethical values associated with the broad suite of services provided by marine ecosystems is important and will require measurement and scaling of those values in relation to other uses. While economists and cognitive psychologists have examined these issues for terrestrial systems, there is little comparable work for marine systems. This too will require collaborative research that brings marine scientists together with social scientists. The task for marine scientists is to elucidate how various fishing strategies affect the structure
of marine ecosystems and alter fundamental processes operating in marine systems. Valuation researchers can then design methods to evaluate how various changes affect humans directly and indirectly and assess those changes to uncover policy options that reflect the most desirable choices. Furthermore, integrated biologic-socioeconomic models should be explored for their capacity to capture important biophysical linkages, translated through to human impacts via economic market valuation methods.
Evaluating management options will require integrated modeling that incorporates not only the best depictions of ecosystem links, but also accurate depictions of fishermen’s behaviors and responsiveness to changes in governance systems. Understanding behavior is a particularly under-researched area, even behavior associated with conventional management systems. Part of the problem is that the data collected in most fisheries are designed by managers for managing with conventional top-down approaches. These data often are aggregated in ways that obscure critical information about the microbehavior of fishermen that would be useful for forecasting behavior under existing or alternative systems. Information should be collected to examine how different kinds of governance mechanisms could potentially change fishermen’s behavior rather than simply regulate it.
Research should also be conducted on how ecosystem management objectives can be incorporated into incentive-based governance mechanisms. Most existing incentive-based systems are primarily single-species focused, but many are also beginning to address broader ecosystem objectives. Existing experiences should be examined and new research conducted on management structures that might best address interspecies linkages, bycatch questions, and broader portfolios of ecosystem services. Research is needed to examine outcomes that might emerge by allowing various user groups to trade allocations. Similarly, a range of experience exists about how bycatch and discards can be incorporated within traditional ITQ or cooperative systems.
New data management, archiving, and access methods should be developed for fisheries research and management.
Fisheries data currently are fragmented and dispersed, thus slowing the use of these data in comprehensive analyses. Improvements to information systems would increase access to historical data, incorporate data from disparate sources, and support the policy-making process. Access to data from diverse sources will facilitate the transformation of these data into useful information that leads to model-based scenario analysis and informed decisions. Large-scale modeling of marine ecosystems requires facile integration of data from multiple sources. Better data management is fundamental to implementing ecosystem-based management of fisheries.
At the outset, the fisheries management community needs to examine existing approaches for the collection and standardization of ecosystem-level data,
including those required by programs, such as the National Science Foundation’s Long-Term Ecological Research, to facilitate across-system comparisons. There is an additional need for a repository and data management system for ecosystem-level research that will allow access to data through multiple-user portals. A comprehensive spatial database of fishing effort, harvest, and other relevant factors could be established, integrating new information management technologies.
Development of an information technology infrastructure that would provide a highly functional platform for scientific endeavors requires meeting challenges in a number of areas: data discovery, access, evaluation, and integration. Other desirable elements include a framework for modeling that provides repositories and documentation for models and model output, frameworks for designing and executing complex workflows, and advanced analysis and visualization tools. Furthermore, the technologic capabilities for ecosystem modeling will be quite intensive. The necessary data management and technology infrastructure should be an essential component of model analysis and scenario generation.