Stock assessment for fishery management - Library

Fishery management systems 11a “comprehensive rational planner” might aim exactly at setting fishing effort or quotasto achieve the model-predicted MSY, a precautionary manager would reduce the effortor quotas according to the level of uncertainty with which the MSY is estimated.In a well-managed fishery with an expensive monitoring and analysis system, this“precautionary MSY” might be quite close to the model-predicted MSY. In a data-poorfishery, it should be much lower, if the fishery is to keep on the safe side.The precautionary approach also proposes a shift in the burden of proof fromthe regulators to the exploiters of the resource. Would-be exploiters need thus showthat their activities will not result in undesirable outcomes for the ecosystem andenvironment, rather than such outcomes having to become evident before managementaction is taken to control them. With this shift in the burden of proof, the incentivefor the fishing industry to reduce uncertainty should be strong. High uncertainty callsfor a high degree of caution, which in fisheries terms means lower catch levels. Betterdata strengthen the scientific basis for management, and thereby reduce uncertaintyand the magnitude of any “precautionary buffers” (Dayton, Thrush and Coleman,2003). Providing good data and working with managers should in theory mean that theindustry will be allowed to catch more fish.The precautionary approach goes well beyond just setting catch limits. The FAOGuidelines (1996) delineate a comprehensive precautionary approach to fisheries as awhole, addressing the sources of uncertainty (and risk) in all aspects of the productionand management process, in research (and the elaboration of advice), management (anddecision-making), monitoring (and performance assessment), control and surveillance(tracking and correcting deficiencies in the system) and in operations (reducing the risksof accidental impact to species and habitats). Mace and Gabriel (1999) have argued thatthe concept of precaution has become over used and that what is really needed is relevantand informative research, and effective monitoring and enforcement. According tothem, it is really management that should be precautionary, e.g. in reducing the quota to75 percent or 80 percent of the estimated MSY according to the uncertainty in theassessment. FAO contends (Garcia, pers. com.) that the capacity of managementto prevent, reduce or mitigate unwanted outcomes depends on the precautionaryperformance of each of the sub-processes mentioned above. Uncertain fishery orbiological data, poor risk assessment (e.g. using simplistic assessment methods),incomplete advice, inadequate risk communication, non-transparent decision-makingand weak enforcement all have the capacity to reduce the precautionary performanceof management no matter how precautionary are the management objectives andrelated reference points (see Section 2.5.2). Hence the need for a more comprehensiveapproach, as recommended by the experts who developed the FAO (1996) guidelines.In such an approach, research will be relevant and informative and enforcement will beeffective (as qualified by Mace and Gabriel) if the risks created by uncertainty, errorsor corruption are systematically tracked and quantified, and conveyed to the decisionmakers.Fishery managers must thus learn to live with uncertainty and may use precautionas one possible solution. Progress with implementing the approach since 1995 hasbeen described by Garcia (2000), ICES (2000), Gabriel and Mace (1999) and others.Several regional fishery management bodies, particularly ICES, NAFO, ICCAT andCCAMLR have adopted the approach, as have some states, notably the United Statesof America, Canada, Australia and South Africa (Garcia, 2000). Different bodies,however, have interpreted the meaning of precaution and the exact definition ofreference points in different ways (see e.g. Section 3.5). Hilborn (2002) emphasizesthat “the vast majority of the world’s fisheries are not precautionary – not because thereference exploitation rates are too high but rather because catch cannot be measuredor catch limits enforced, or because abundance cannot be estimated, or because rulesdo not state how catches will change in relation to stock size.”