The committee’s purpose in this chapter is to offer suggestions for consideration as part of long-term strategic planning for fisheries rebuilding and for potential application to ecosystem-based fisheries management (EBFM). The chapter begins with discussion of the overarching issue of how to achieve a balance between the current prescriptive approach and an alternative approach that would allow rebuilding plans to be more tailored to the specific circumstances of the fishery, the environment, and the scientific information available. The chapter then covers seven topics that are directly or indirectly related to the overarching issue of prescriptive versus flexible approaches: definition of success for rebuilding plans; rebuilding plans and EBFM; rebuilding time frames; model predictions, projections, and data and knowledge limitations; mixed-stock fisheries; the role of biological science and socioeconomic factors; and communication with stakeholders.
Overarching Issue: What Is the Best Balance Between Prescriptiveness and Flexibility?
(Findings 2.2, 2.3, 3.10, 5.1, 6.1, 6.4)
The rebuilding approach, established by the current legal framework and the Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA) guidelines, is highly prescriptive. Under this approach, management of individual stocks is based on specified biomass thresholds and targets, a fishing mortality limit, catch reductions in consideration of various types of uncertainty, accountability measures, and a specified maximum time period within which rebuilding must occur with at least a 50% probability. The guidelines for implementing rebuilding also stipulate the process by which scientific advice is formulated and conveyed. The committee’s comments on the prescriptive approach relate to the specifics of the current guidelines for rebuilding.
A prescriptive approach is beneficial in that it reduces delays in taking corrective action when stocks become depleted and clearly specifies the steps involved in formulating the plan, identifying required rebuilding targets, and tracking progress toward rebuilding. The prescriptive approach also limits the use of short-term socioeconomic costs to argue for a delay in rebuilding that would, if successful, provide long-term socioeconomic benefits. In addition, the prescriptive approach can (but is not guaranteed to) ensure that scientific advice is followed, which improves accountability because of clear tractability (e.g., identification of targets) and thus clearer communication about the status of fish stocks. The disadvantage of the prescriptive approach is that, by definition, it leaves little room for flexibility or innovation (e.g., use of alternative stock-specific reference points) and precludes tailoring of rebuilding plans to the specifics of each stock and its fisheries. Furthermore, satisfying the specific mandates of the rebuilding guidelines may divert attention from achieving the broader goals of EBFM.
The tradeoff between flexibility and prescriptiveness within the current legal framework for rebuilding underlies many of the issues discussed in this chapter. The current approach may not be flexible or adaptive enough in the face of complex ecosystem and fishery dynamics when data and knowledge are limiting. A high degree of prescriptiveness (and concomitant low flexibility) may create incompatibilities between single-species rebuilding plans and EBFM. Fixed rules for rebuilding times may result in inefficiencies and discontinuities of harvest-control rules, place unrealistic demands on data and models for stock assessment and forecasting, cause reduction in yield, especially in mixed-stock situations, and de-emphasize socioeconomic factors
in the formulation of rebuilding plans. The current approach evaluates success of individual rebuilding plans in biological terms, not in socioeconomic terms or at broader regional and national scales. It does not ensure effective flow of information across regions. The committee expands on each of these issues below and discusses ways to increase efficiency without weakening the rebuilding mandate.
Defining Success of Rebuilding Fisheries
(Findings 2.1, 3.5, 3.6, 3.8, 5.9, 6.1, 6.2, 6.3, 6.9)
The committee’s evaluation of rebuilding plans focused quantitatively on biological metrics, consistent with current legal mandates. Beyond those, there is a lack of consensus concerning what, specifically, is implied by overall (not just biological) rebuilding success. Although this is a basic question, finding the answer can be quite complicated. Ideally, rebuilding plans should balance the trade-offs between the expected socioeconomic impacts and the reductions in fishing pressure to rebuild stocks in a given time period, and more effective management would ensure that no stocks would be designated as overfished in the future. However, this is unlikely to happen. So what is a realistic basis for judging the overall performance of individual rebuilding plans, and what is a realistic standard for overall success at the national level?
Each rebuilding plan has an acknowledged possibility of failing to achieve a given rebuilding target by the specified time because rebuilding plans are acceptable if their associated probability of rebuilding, estimated at time of adoption, is 50% or greater. Even if a higher success rate (e.g., 90%) were required, some of the rebuilding plans would not achieve their objectives on schedule. Stocks may rebuild faster or slower than expected because of environmental influences. Thus, from just the biological perspective, nationwide “success” is possible even if some individual stocks fail to rebuild by the agreed time or ever.
The approach to evaluating the success of rebuilding plans should examine the portfolio of stocks, and it should quantify how many stocks are rebuilding ahead of schedule and how many are rebuilding behind schedule in comparison to the probability of success with which the plans were designed. In addition, the approach should distinguish cases in which fishing mortality was not reduced as intended from those in which stocks failed to show signs of rebuilding in spite of reduced fishing mortality. The committee’s analysis of rebuilding plans indicated that when fishing mortality was effectively reduced, only a few stocks did not show an increase in biomass.
At the national level, there will always be stocks classified as overfished and in need of rebuilding for several reasons: rebuilding plans are not designed to rebuild stocks on schedule with absolute certainty, some stocks are incorrectly categorized as overfished because of scientific uncertainty, and changes in environmental and ecological conditions preclude rebuilding to targets based on historical stock levels.
In addition to biological benchmarks, rebuilding plans have socioeconomic impacts that are also an important component in judging success. Currently, only a subset of the socioeconomic costs and benefits of rebuilding are typically quantified or systematically considered in the evaluation of rebuilding plans, and the analyses varies among the Regional Fishery Management Councils (RFMCs) and often involve simplifying assumptions that limit their long-term applicability. A national discussion on defining success in rebuilding plans, including identification of suitable, quantitative measures of performance, would help to clarify the overall goals of rebuilding and to enable the review of the progress of rebuilding in a more general rather than a stock-by-stock context. How should biological and socioeconomic factors be considered in evaluations of overall success? Although consensus is unlikely, regional discussions that feed into a national discussion could lead to greater understanding of stakeholder views and perspectives, which in turn would improve the perceived relevance and credibility of the science and the legitimacy of the decision-making process.
Rebuilding Under Ecosystem-Based Fisheries Management
(Findings 2.1, 5.1, 5.3-5.6, 6.8, 6.10)
The current focus of rebuilding plans on a stock-by-stock basis with Maximum Sustainable Yield (MSY)-based targets offers advantages (e.g., clear benchmarks and tractability). In addition, the use of output controls, such as catch limits, provides a direct and measurable mechanism for controlling fishing mortality, albeit with uncertainty. However, how such stock-specific rebuilding measures fit within EBFM is unclear. It is conceivable that the focus on stock-specific rebuilding plans that rely on output controls can, in some situations, be difficult to mesh with, and even be detrimental to, EBFM objectives. EBFM is still only conceptually defined, although progress is being made to move from proof of concept to operational use. Formal approaches to evaluating management strategies, which are often based on multi-species or ecosystem models, offer promise for exploring the long-term performance of rebuilding plans and strategies beyond the responses of individual stocks. However, at this time, these highly parameterized multi-species and ecosystem models are essentially “best guesses” that have not been thoroughly assessed for performance and skill. The use of such models will require additional effort for their results to play a stronger role in strategic planning and to inform specific rebuilding situations. There remains a gap between the approaches used for stock-specific rebuilding and those used for EBFM.
Rebuilding Time Frames
(Findings 2.2, 3.3, 3.7, 4.2, 4.6, 5.9, 6.2)
The use of a simple fixed rule for determining the maximum number of years to rebuild is, in principle, an effective way to ensure that rebuilding occurs at a reasonable pace. A rule that sets the maximum time horizon in a rebuilding plan clearly reduces the potential for delaying restrictions on fishing into the future.
However, fixed rules for specifying the rebuilding time frame can create inefficiencies in practice. First, a problem may arise with the specific formulation of the rule. The existing 10-year rule uses TMIN to determine a minimum possible rebuilding time, which is useful because it accounts for the initial stock condition and expected productivity. However, the determination of TMAX exhibits a discontinuity at 10 years (see Figure 4.1) that has the potential to create discontinuities in target dates for recovery (10 years to many decades) based on only small changes in estimates of stock size from assessments.
Second, a fixed maximum time for rebuilding restricts the consideration of socioeconomic impacts, especially when the range of acceptable rebuilding periods (i.e., from TMIN to TMAX) is narrow. The allotted rebuilding time can lead to substantial increases in rebuilding costs if the incremental additional costs from rebuilding are sensitive to the rebuilding schedule. As described in Chapter 6, it is sometimes possible for modest changes to a rebuilding schedule to have nontrivial effects on net social benefits; such adjustments are often precluded from consideration under current requirements. Abrupt changes in management actions can have real economic and social impacts on communities and can influence the perceptions and attitudes of stakeholders and managers.
Third, a fixed time to rebuilding can be problematic when rebuilding is faster or slower than expected, resulting in over-reaction and misinterpretation of the causes. Faster rebuilding can lead to premature demands to relax restrictions, which could slow the rate of rebuilding. In contrast, slower rebuilding can lead to severe reductions in target fishing mortality in an effort to achieve the target biomass by the predetermined date. Rebuilding can occur slower than expected because of unexpectedly low recruitment, an ecosystem change, or failure to reduce fishing mortality due to imprecise or inaccurate science, or to catches exceeding desired levels (fishing mortality is higher than the target level). When recruitment is below expectations (e.g., because of unfavorable environmental conditions), a control rule based on maintaining fishing mortality at some fraction of FMSY may be more efficient than one that forces increasingly severe controls to keep rebuilding on schedule. Such a control rule could be formulated to ensure achievement of the rebuilding goals when environmental conditions become more favorable.
Future discussions of the goals and design of rebuilding plans should consider the benefits and costs of flexibility in determining the time to rebuild so that new scientific information and socioeconomic impacts can be taken into account during rebuilding. Determining when and how within the rebuilding process to introduce additional flexibility that properly accommodates biological and socioeconomic factors is a challenge. Experience from other countries indicates the effectiveness of legal mandates similar to those in the United States in terms of demanding reductions in fishing mortality but different in allowing for greater flexibility in setting the time horizon for rebuilding. The international experience, however, may not be fully applicable to the United States because other aspects of the fishery management systems, such as the role of industry interests in decision making, differ among countries, which makes direct comparisons difficult.
Model Predictions, Projections, and Data Limitations
(Findings 2.1, 3.5, 3.9, 4.1, 4.4, 4.7, 4.8, 5.1, 5.5. 5.6-5.8, 6.3)
There remains insufficient data and information to allow for model-based projections for many stocks. This will continue to be a challenge for providing management advice in general, and for designing rebuilding plans in particular. Most of the committee’s analyses and commentary in Chapters 2 through 6 focused on the stocks for which projections of stock size and estimation of fishing mortality and biomass-based benchmarks are possible. However, many stocks can be characterized as data-poor, implying that stock projections cannot be conducted and therefore benchmarks for either status determination or rebuilding cannot be established. Indeed, the stock status of more than half of the nation’s 479 managed stocks or stock complexes was unknown at the end of 2012.
Knowledge may be limited even for stocks for which data are abundant. For example, several plausible alternative models that explain the data can still produce different predictions. How to deal with these data-poor and knowledge-poor stocks, both in assessing their status and then, if appropriate, in formulating rebuilding plans, has been a long-standing challenge. The current implementation of rebuilding to meet the mandates of the MSFCMA can, in some situations, place demands on the available information and models that are beyond current capabilities and therefore can introduce high uncertainty.
When data-poor stocks (and perhaps some knowledge-poor stocks) require rebuilding, spatial and habitat-based approaches (e.g., marine zoning including Marine Protected Areas), with empirical rules to adjust harvest controls in response to abundance trends demographic indicators as well as ecosystem-level indicators (e.g., prey abundance), provide a less data-intensive alternative. When data are too limited to perform stock assessments and estimate biomass and
fishing mortality with sufficient confidence, demographic indicators can be used to adjust management controls to ensure that fishing rates are reasonable and precautionary and that rebuilding is progressing. It may be possible to use ecosystem, habitat, and demographic indicators as practical alternatives, or in conjunction with other fisheries information, within a more flexible rebuilding protocol.
The current approach to rebuilding, which requires projections of stock biomass many years (often decades) into the future, results in interpretation of these projections to a degree that is on the edge or beyond the capability of current models. Stock biomass estimates and projections can vary greatly in response to alternative plausible assumptions (models) and parameter values used in simulations. The stable dynamical behavior often assumed in stock assessment models (e.g., spawner-recruit relationships) may not replicate the nonlinear population dynamics observed in fisheries data: as a consequence, these models may generate inaccurate projections.
Although their quality varies among stocks, the data and models are rarely robust enough to generate projections that accurately forecast stock size over the next decades. Rather, model projections, especially when alternative plausible models exist, can be viewed as useful tools to explore the performance of rebuilding strategies in scenario mode (comparative or relative outcomes), with an emphasis on adequate feedback and adaptive responses rather than on predictions of future biomasses. However, this use of model projections does not fulfill current management requirements, especially in terms of biomass-based metrics.
Increased flexibility could promote more rapid consideration and adaptation of new methods and could allow for the design of more robust rebuilding plans for both data and knowledge-poor stocks. One idea is to replace the current rebuilding strategy (biomass benchmarks with a defined time horizon) with an equally rigorous approach based on controlling fishing in the near term (i.e., years not decades) and managing based on the short-term projected directions of stock change or fishing rates relative to FMSY. Projections of fishing mortality relative to FMSY tend to be more robust than are projections of biomass relative to biomass reference points, although this assertion would need to be confirmed for each stock.
Short-term forecasts can be made using age-structured models and statistically based methods, especially in cases where stock dynamics are not dominated by unpredictable recruitment or highly variable mortality, although general real-time validation of forecast performance is largely lacking. New empirical modeling techniques can be tailored to management metrics operating with variable recruitment and mortality. Such models focus on short-term rates of change and the inherent nonlinearity in fish population and community responses to environmental and biological changes (e.g., Boxes 5.1 and 5.2). Although no modeling technique is perfect, a shift toward shorter-term forecasting and heavier reliance on fishing-mortality-related metrics could make rebuilding plans more robust to some aspects of model uncertainty.
(Findings 4.5, 5.5, 5.6, 5.7)
Rebuilding of mixed-stock fisheries will remain challenging because of the need to weigh tradeoffs among species. Although the mixed-stock problem was acknowledged in the current guidelines of the MSFCMA, the committee is unaware of any cases where the “mixed-stock exception” has been applied in rebuilding plans.
Attempting to deal with the mixed-stock problem will require analyses and modeling of fisheries and economics data to identify appropriate solutions, as well as flexibility to apply mixed-stock exceptions (where applicable). One challenge is the development of mixed-stock fisheries models that allow for evaluation of tradeoffs. Such models have been proposed (Chapter 6), but they require further evaluation and testing. Use of the projections from these models is limited by the availability of data on each of the species in the mixed stock fisheries, their biological and technical interactions, and the relevant socioeconomic data, but more data are becoming available.
A second challenge is to design operational regulations and incentivize fishing practices that adequately protect weak stocks while providing fishing opportunities for healthy stocks. The MSFCMA requires that fishing mortality be kept below FMSY for all stocks and that time-constrained rebuilding plans be implemented for all overfished stocks. This constraint requires forgoing benefits to achieve rebuilding goals for even the most insignificant stocks in terms of value or ecosystem function. Such precaution is necessary when extinction is an issue. However, there is usually a wide range of choices between FMSY and the rate of fishing mortality that increases risk of extinction to a noteworthy extent, but such considerations of fishing mortality are not allowed under the MSFCMA. Rebuilding plans could be designed to allow for harvesting of healthy stocks in mixed-stock situations, while preventing weak stocks from being driven to unacceptably low abundance.
Role of Biological Science and Socioeconomic Factors
(Findings 6.1, 6.3-6.7, 6.9, 6.10)
The net economic and other social benefits of successful rebuilding are often (although not always) positive in the long run. There is often a time lag between rebuilding fish stocks and rebuilding the fisheries that depend on them. Rebuilding plans necessarily involve a reduction in fishing pressure, and the rebuilt fishery will require less fishing capacity than before. Only a subset of the socioeconomic costs and benefits are typically quantified or systematically considered when evaluating rebuilding plans, the analyses of these costs and
benefits varies across RFMCs, and the analyses often involve simplifying assumptions that limit their long-term applicability. The existing rules (e.g., 10-year rule) and guidance, along with the limited application of the mixed-stock exception, prevent consideration of possible harvest options that could otherwise improve socioeconomic outcomes. This situation contributes to stakeholders contesting rebuilding plans because of the perceived and real socioeconomic impacts and to stakeholders appealing for and securing mitigation measures from Congress, NOAA, and others.
A broader dialogue could help determine how and when socioeconomic information should be introduced into the process of developing rebuilding plans. The deliberations would increase mutual understanding among industry, managers, scientists, nongovernment organizations (NGOs), and other stakeholders, improve transparency in decision making, and enhance opportunities to apply rapidly advancing social sciences methods to select management and mitigation measures for rebuilding plans. Ultimately, explicit consideration of socioeconomic impacts is critical: the current process of evaluating potential socioeconomic outcomes contingent upon the prior establishment of biological parameters precludes consideration of potential rebuilding plans with superior socioeconomic properties (e.g., greater benefits or smaller costs).
The challenge exists in how to appropriately include socioeconomic considerations while maintaining the tractability and impetus for action that many consider a positive aspect of current rebuilding guidelines. Coupled human-natural systems models are starting to be developed that could eventually be used to achieve a more effective balance (Chapter 6). Systems-based approaches, and formal models of decision making under uncertainty, are some of the options that can help to promote a more transparent, deliberative process for developing rebuilding plans, thereby encouraging better integration of biological and socioeconomic considerations.
A second challenge centers on how to provide scientific advice when plausible, alternative models exist. The Scientific and Statistical Committees (SSCs) and other review bodies can provide singular advice when there is a best model, the alternative models generate similar results, or it is scientifically appropriate to combine the results from multiple models. Ideally, a weighting could be applied to the combined results based on rigorous out-of-sample testing. However, this kind of validation is rarely practiced. When there is no scientific basis for selecting one model over another (or others), SSCs and other review bodies should present the results from multiple approaches (ideally including socioeconomic aspects) to the managers. The implications of alternative management decisions based on the different, plausible models should be included in the advice and should be part of the managers’ deliberations as they weigh biological and socioeconomic considerations.
Need for Effective Communication and Stakeholder Engagement
(Findings 6.3, 6.4, 6.6)
Finally, as is always the case with controversial issues when science and policy intersect, the importance of clear communication and effective stakeholder engagement is critical. The search for effective methods of communication must continue. Collaborative research and monitoring among fishermen, managers, and scientists offer one avenue for communication and engagement (Chapter 6). Transparency in the capabilities of the models used for developing rebuilding plans, how and what sources of uncertainty were quantified, and how socioeconomic factors were considered is also necessary for communication and for informed decision making. A more formal description and implementation across rebuilding plans and RFMCs would enhance the perceived credibility of the science and the legitimacy of the decision-making process in the eyes of industry, NGOs, the public, U.S. Congress, and other stakeholders.
The current implementation of the MSFMCA relies on a highly prescriptive approach that has demonstrated successes in identifying and rebuilding overfished stocks. Overall, for overfished stocks placed under a rebuilding plan, fishing mortality has decreased, and stock biomass has increased when fishing mortality was successfully reduced. Where they have been estimated, the long-term net economic benefits of rebuilding appear to be generally positive. Stocks that rebuilt or whose biomass increased appreciably were, in almost all cases, experiencing fishing mortalities below FMSY, and often less than 75% of FMSY. Extreme reductions in target fishing mortalities have been implemented for stocks for which rebuilding progress was slower than anticipated and the target year for rebuilding was approaching. The strong legal and prescriptive nature of rebuilding forces difficult decisions, ensures a relatively high level of tractability, and can help to prevent protracted debate over whether and how stocks should be rebuilt.
The present single-stock approach to rebuilding can, however, lead to inefficiencies. The perceived status of a stock can change with subsequent assessments. This can occur because of new data or assumptions in the more recent assessment that indicate that rebuilding is slower or faster than expected or that the stock biomass was likely higher than it appeared (e.g., not overfished) at the time it was declared overfished. Some stocks have not increased in biomass at the expected rate despite lowered fishing mortality rates, forcing more extreme reductions in fishing mortality to meet the rebuilding timeline. In some other cases, rebuilding plans have failed to reduce fishing mortality as much as intended, either because of overestimation of stock sizes or implementation issues, and rebuilding has been slow or
not occurred. The inefficiencies that result from changes in stock assessments, lack of expected stock responses, or failure to achieve needed reductions in fishing mortality rates have sometimes incurred substantial negative biological and economic consequences (e.g., too low stock biomasses, lost future yields). Subsequent adjustments to rebuilding plans can cause further substantial economic and social impacts (e.g., highly restricted fishing). In addition, the current approach is not as effective for the many data-poor stocks for which overfished status is unknown (more than half of the nation’s stocks). Even with well-studied stocks, the current approach forces reliance on forecasts and biomass-based reference points that are sometimes highly uncertain. Some stocks may not conform to their rebuilding plans because of environmental variability, ecosystem interactions, or failure of the stock models to adequately account for nonlinear dynamics. Furthermore, for mixed stocks the stock-specific approach can result in fisheries forgoing yield of a healthy stock to allow rebuilding of a weak stock. In general, the current requirements have led to socioeconomic considerations playing a secondary role in the design of rebuilding plans. Finally, there is a lack of standardization across geographic regions as to how rebuilding plans are developed and implemented.
The committee used the evaluation, discussion, and findings presented in Chapters 2 through 6 as a basis for this final chapter, taking a long-term view at further improving the current approach to stock rebuilding. Although Chapters 2 through 6 focus on rebuilding within the current legal framework, this chapter describes avenues for long-term planning in the development of stock rebuilding strategies over the next decades. The committee identified seven topics that directly or indirectly relate to the overarching issue of what should be the appropriate degree of flexibility in stock rebuilding. This chapter describes alternatives that could be more effective for developing rebuilding plans than the current approach, given the complex and variable nature of ecosystems, the dynamics of coupled human-natural systems, and the considerable uncertainty in fishery science. Many comments could serve as suggestions for research and for informing future revisions of the National Standard Guidelines to improve the overall performance of stock rebuilding programs and thereby enhance the benefits derived from fisheries in the future.