Transition from Low to High Data Richness: an Experiment in Ecosystem-based Fishery Management from California

Fisheries can cause major impacts on ecosystems, but the goal of managing them sustainably requires more and different information than we now have. Few fisheries have the legal mandate for ecosystem-based management or to apply precautionary management when information is lacking, so fishermen have little incentive to demand improved information. The California Marine Life Management Act of 1998 requires the maintenance of ecosystem health and diversity in California s̓ complex nearshore ecosystems. We present the key elements, the scientific rationale, and an implementation plan for the transition from information-poor, precautionary management to information-rich, spatially explicit ecosystem-based management in the California nearshore finfish fishery. These elements are included in a fishery management plan adopted by the state in 2002. Marine reserves serve as reference points in repeated-measures before–after control-impact experimental design, in addition to their more familiar conservation benefits. The complexity of scientific monitoring, the statistical power of the monitoring design, and the benefits to consumptive and nonconsumptive uses and values all increase from information-poor to information-rich management. The most significant scientific hurdle comes with incorporation of ecosystem and environmental variability effects. Resource managers and fishery scientists generally agree that caution must be given higher priority in management of our impacts on wild stocks and on the ecosystems that sustain them. Agreement is also growing that fishery management must go beyond single-species impact management to incorporate ecosystem considerations explicitly. The goal is a sustainable relationship between man and the sea. This approach, in which ecological integrity is given greater importance than short-term benefits to the human enterprise (Stanley, 1995), is called “ecosystem-based management” (EBM). EBM for fisheries has been endorsed by the European Union, the United Nations Food and Agriculture Organization, the National Research Council, the National Marine Fisheries Service, and even some fishery management councils (North Pacific Fishery Management Council, 1999). Data acquisition designed specifically to support EBM is progressing in the Gulf of Alaska/Bering Straits region (Livingston, 1999) and California (the present paper). Now we are down to the details of making EBM work. THE SURPLUS PRODUCTION MODEL AND ECOSYSTEM-BASED MANAGEMENT With adequate resources, fishery biologists can estimate fish populations and biomass on the basis of landings (fishery-dependent data) and fishery surveys (fishery-independent data). These data are put into population models that calculate the number or biomass of any one species that can be taken without sending its stock into decline. These are called “surplus production” models and are fraught with serious pitfalls (Graham, 1935; Larkin, 1977). By this means, up to 40% of the ocean s̓ production has been deemed “surplus,” available for human use. In addition to providing sport and food for humans (either directly or as fertilizer or food for farmed fish), the marine species that we catch also BULLETIN OF MARINE SCIENCE, VOL. 74, NO. 3, 2004 694 play various roles in supporting each other s̓ populations, as well as functioning as part of an ecosystem that is deemed valuable by noncommercial criteria, ranging from ethical to utilitarian. Fishing a species at its theoretical maximum sustainable yield (MSY), or even its optimum yield (OY) as OY has routinely been interpreted, greatly diminishes that speciesʼ function as a predator, prey, or symbiont to other perhaps equally desirable species. These relationships complicate management of multispecies fisheries and multiple fisheries in one system. For example, the sum of the MSYs for all of the species in a fishery cannot be sustainable in the aggregate; it is not possible to maximize yield by this means for many species at once (Brown et al., 1976; May et al., 1979; Link, 2002b). The standard MSY approach also tends to overlook humansʼ status as versatile predators with very complex behavior (Johnson, 1994). Finally, the MSY approach conveys the notion that fish populations are under direct human control. The inherent fallacy in this “command and control” approach to human interactions with “complex, nonlinear, and poorly understood” natural systems has been clearly pointed out by Holling and Meffe (1996) among others. Scientific effort can be adjusted to provide the necessary additional information on multispecies considerations, ecosystem effects, and even changing ocean conditions, and the results incorporated into management. Up to now most real-world applications of EBM have concerned by-catch reduction for endangered or endearing nontarget species that fall prey to a particular fishery (e.g., Steller sea lion in the Bering Sea) plus rare consideration of nontarget species and environmental change (e.g., Pacific sardines in the California Current System, Pacific Fishery Management Council, 1998a). THE MARINE LIFE MANAGEMENT ACT: A NEW PARADIGM FOR CALIFORNIA FISHERIES MANAGEMENT The situation for fishery management is now distinctly different in the state of California, where by law it must now become ecosystem based. As a single jurisdiction that is now legally friendly to EBM, California provides a good case study of the transition between old and new approaches. California s̓ Marine Life Management Act (MLMA), which became law in 1999, requires that human activities in the ocean be sustainable. The MLMA defines “sustainable” uses as those that secure the fullest range of present and long-term ecological benefits, including maintenance of biological diversity (Weber and Heneman, 2000). This goal is a challenge given California s̓ size, complex nearshore ecology, and multispecies fisheries. Moreover, because the MLMA concerns more than fishery management, it also requires consideration of nonconsumptive uses. The MLMA also required the state to begin managing its fisheries with management plans (FMPs). The second FMP, and the first multispecies plan, mandated by the MLMA was for the complex nearshore finfish fishery. THE NEARSHORE FISHERY MANAGEMENT PLAN AND THE PATH TO EBM In 2000, the Secretary of Commerce joined the governors of California, Oregon, and Washington to declare the federally managed West Coast groundfish fishery a disaster. In the fall of 2002, federal managers closed most of the continental shelf portion of this fishery, a situation likely to continue for decades because of the lengthy rebuilding timetables for bocaccio (Sebastes paucispinus) and other Sebastes species. Target populations of most state-managed fishes and invertebrates were fully or overexploited. These KAUFMAN ET AL.: FROM LOW TO HIGH DATA RICHNESS 695 federal closures are expected to cause increased recreational and commercial pressure on the state-managed nearshore finfish species included in the nearshore FMP (NFMP). As a result, the closures provide a strong incentive to improve management in the nearshore. The “nearshore,” ill defined in the state s̓ NFMP, includes the bulk of the ranges of 19 finfish species resident mostly in rock and kelp habitats that support the recreational and commercial nearshore fishery (Table 1). The 19 species, and fishing activities for them, are concentrated in depths less than 40 m and rarely penetrate beyond 80 m. The commercial fishery is primarily a live-fish fishery, pursued with hook-and-line gear and traps, so habitat damage due to fishing is minimal. Fishing is currently the dominant human impact on the NFMP species, although with marked regional variation in character both biologically and socioeconomically. The challenge for the California Department of Fish and Game was to craft an FMP for the 19 species that incorporated the best of classical single-species management while fulfilling MLMA mandates for sustainability, ecosystem conservation, and nonconsumptive uses. STAGED RISK REDUCTION—SUMMARY OF THE NFMP CONTROL RULE The MLMA applies to all components of the nearshore marine ecosystem, not just finfishes, but California did not have the capacity to jump instantly into ecosystem-impact management. A three-stage blueprint was therefore designed to phase in EBM. At its heart, the NFMP is conventional in having a control rule that relates total allowable catch (TAC)—fishing mortality—to population size. Like any other effective fishery management policy, it also defines overfishing and prescribes what to do about it. Beyond this point, however, the control rule for the NFMP is unconventional in emphasizing three underlying principles: First, certain irreducible uncertainties may never be resolved, so precaution at the outset is essential. The need for precaution can be reduced with improved information, though never eliminated. Second, single-species management has commonly tended toward inadvertent overexploitation. Ecosystem-based management requires the application of more conservative tools to address this problem and reduce the risk of overexploitation. Third, better information may ultimately result in higher TACs. The control rule (drafted by the authors) that was incorporated in the NFMP and adopted by the California Fish and Game Commission in August 2002 is intended to meet three fundamental objectives: (1) to maintain healthy populations of target species, (2) to avoid extreme fishery effects on the ecosystem, and (3) to anticipate the effects of environmental change on the fished populations. Finally, the control rule proceeds through a progression of three stages that provide a transition from information-poor to information-rich human-impact management: Stage I, data-poor (precaution the primary basis for setting TACs); Stage II, data-moderate (improved single-species or multispecies management and a transition from blind precautionary management to informed risk management); and Stage III, data-rich (ecosystem-based fishery management). We borrowed some of the terminology above from Restrepo et al. (1998), but our definitions are necessarily different. Restrepo et al. were concerned with a surplus-production model and explicitly did not consider ecosystem relationships or environmental flux. BULLETIN OF MARINE SCIENCE, VOL. 74, NO. 3, 2004 696 The descriptions of the three stages imply a stepwise progression, but implementation will differ in degree and timing for different species and regions. The jump from Stage I to Stage II is dramatic, because the Stage II information threshold allows a fundamental change in the approach to setting TACs. Transition to Stage III, however, will proceed by small steps and cumulatively as new information is incorporated into ecosystem-impact and environmental-change models. The control-rule approach allows the triggers for regulatory action to change as information quality and quantity improve and as the system itself undergoes flux. The control-rule approach looks very much like an MSY/OY control rule in which MSY is reset every year or so on the basis of new information and where TACs truly incorporate catch reductions for relevant ecological factors (as in the Magnuson-Stevens Fishery Conservation and Management Act definition of OY). The novelty here is the explicit, staged approach to integration of different levels of information about the demographics of target species with different levels of information about ecosystem relationships. The three stages produce formulas for deriving TACs that are appropriate for a given level of awareness about the system. The result is a control rule intended to ensure sustainable catches as defined in the MLMA. Specifically, the result will be a level of catch that allows the maintenance of all of the ecological benefits and biological diversity in the nearshore ecosystem. Control of total mortality in target species will limit fishery-caused changes in ecosystem process indicators (e.g., food-web length). Table 1. The 19 species of finfishes covered by Californiaʼs Nearshore Fishery Management Plan. Species Common name Depth range (m)