Ocean harvests have plateaued worldwide and many important commercial stocks have been depleted. This has caused great concern among scientists, fishery managers, the fishing community, and the public. This book evaluates the major models used for estimating the size and structure of marine fish populations (stock assessments) and changes in populations over time. It demonstrates how problems that may occur in fisheries dataâ€"for example underreporting or changes in the likelihood that fish can be caught with a given type of gearâ€"can seriously degrade the quality of stock assessments. The volume makes recommendations for means to improve stock assessments and their use in fishery management.
The collapse of cod, flounder, and haddock fish stocks in the Northeast United States has caused widespread concern among managers and fishers in the United States and Canada. The diminishing stocks have forced managers to take strict regulatory measures. Numerous questions have been raised about the adequacy of stock assessment science used to evaluate the status of these stocks and the appropriateness of the management measures taken. Based on these concerns, Congress mandated that a scientific review of the methodology and data used to evaluate these stocks be conducted. In this volume, the committee concludes that although there are improvements to be made in data collection, modeling uncertainty, and communicating between fishers, managers, and scientists, the scientific methods used in the Northeast stock assessments are sound. Recommendations are made on how the stock assessment process can be improved.
The National Marine Fisheries Service (NMFS) is responsible for the stewardship of the nation's living marine resources and their habitat. As part of this charge, NMFS conducts stock assessments of the abundance and composition of fish stocks in several bodies of water. At present, stock assessments rely heavily on human data-gathering and analysis. Automatic means of fish stock assessments are appealing because they offer the potential to improve efficiency and reduce human workload and perhaps develop higher-fidelity measurements. The use of images and video, when accompanies by appropriate statistical analyses of the inferred data, is of increasing importance for estimating the abundance of species and their age distributions. Robust Methods for the Analysis of Images and Videos for Fisheries Stock Assessment is the summary of a workshop convened by the National Research Council Committee on Applied and Theoretical Statistics to discuss analysis techniques for images and videos for fisheries stock assessment. Experts from diverse communities shared perspective about the most efficient path toward improved automation of visual information and discussed both near-term and long-term goals that can be achieved through research and development efforts. This report is a record of the presentations and discussions of this event.
Most U.S. fish stocks are fully or over-exploited, and harvesting in many fisheries far exceeds sustainable levels. The individual fishing quota (IFQ) is a relatively new instrument under which harvesting privileges are allocated to individual fishermen--innovative yet controversial for its feared effect on fishing communities and individual fishermen. Based on testimony from fishermen, regulators, environmentalists, and others, Sharing the Fish explores how IFQs might address the serious social, economic, and biologic issues raised by depleted fish stocks. In their approach to a national policy on IFQs, the panel makes direct recommendations to Congress, the Secretary of Commerce, the National Marine Fisheries Service, regional fishery management councils, state authorities, and others. This book provides definitions and examples, reviews legislation and regulations, and includes lessons learned from fisheries on the U.S. East Coast and in Alaska, and in Iceland, New Zealand, and other nations. The committee discusses the public trust doctrine, management of common-pool resources, alternative and complementary approaches to the IFQ, and more. Sharing the Fish provides straightforward answers that will be important to fishery policymakers and regulators, natural resource economists, fishery managers, environmental advocates, and concerned fishermen and their communities.
Ocean harvests have plateaued worldwide and many important commercial stocks have been depleted. This has caused great concern among scientists, fishery managers, the fishing community, and the public. This book evaluates the major models used for estimating the size and structure of marine fish populations (stock assessments) and changes in populations over time. It demonstrates how problems that may occur in fisheries dataâ€"for example underreporting or changes in the likelihood that fish can be caught with a given type of gearâ€"can seriously degrade the quality of stock assessments. The volume makes recommendations for means to improve stock assessments and their use in fishery management.
Most U.S. fish stocks are fully or over-exploited, and harvesting in many fisheries far exceeds sustainable levels. The individual fishing quota (IFQ) is a relatively new instrument under which harvesting privileges are allocated to individual fishermenâ€"innovative yet controversial for its feared effect on fishing communities and individual fishermen. Based on testimony from fishermen, regulators, environmentalists, and others, Sharing the Fish explores how IFQs might address the serious social, economic, and biologic issues raised by depleted fish stocks. In their approach to a national policy on IFQs, the panel makes direct recommendations to Congress, the Secretary of Commerce, the National Marine Fisheries Service, regional fishery management councils, state authorities, and others. This book provides definitions and examples, reviews legislation and regulations, and includes lessons learned from fisheries on the U.S. East Coast and in Alaska, and in Iceland, New Zealand, and other nations. The committee discusses the public trust doctrine, management of common-pool resources, alternative and complementary approaches to the IFQ, and more. Sharing the Fish provides straightforward answers that will be important to fishery policymakers and regulators, natural resource economists, fishery managers, environmental advocates, and concerned fishermen and their communities.
The collapse of cod, flounder, and haddock fish stocks in the Northeast United States has caused widespread concern among managers and fishers in the United States and Canada. The diminishing stocks have forced managers to take strict regulatory measures. Numerous questions have been raised about the adequacy of stock assessment science used to evaluate the status of these stocks and the appropriateness of the management measures taken. Based on these concerns, Congress mandated that a scientific review of the methodology and data used to evaluate these stocks be conducted. In this volume, the committee concludes that although there are improvements to be made in data collection, modeling uncertainty, and communicating between fishers, managers, and scientists, the scientific methods used in the Northeast stock assessments are sound. Recommendations are made on how the stock assessment process can be improved.
Recreational fishing in the United States is an important social and economic component of many marine fisheries, with an estimated 14 million anglers making almost 82 million fishing trips in 2004. Although each individual angler typically harvests a small number of fish, collectively these sport fisheries can take a significant fraction of the yearly catch-in some cases more than commercial fisheries. For example, in 1999, recreational fishing accounted for 94% of the total catch of spotted sea trout, 76% of striped bass and sheephead, and 60 percent of king mackerel. It is important that systems used to monitor fishing catch are adequate for timely management of recreational fisheries. However, the large number of anglers and access points makes monitoring recreational fishing much more difficult than monitoring commercial fishing. This report reviews the types of survey methods used to estimate catch in recreational fisheries, including state/federal cooperative programs. The report finds that both telephone survey and onsite access components of the current monitoring systems have serious flaws in design or implementation. There are also several areas of miscommunication and mismatched criteria among designers of surveys, data collectors, and recreational fisheries. The report recommends that a comprehensive, universal sampling frame with national coverage should be established, and that improvements should be made in statistical analysis of the data collected and in the ways the data are communicated. A permanent and independent research group should be established and funded to evaluate the statistical design and adequacy of recreational fishery surveys and to guide necessary modifications or new initiatives.
The National Marine Fisheries Service (NMFS) of the National Oceanic and Atmospheric Administration (NOAA) is responsible for collecting information on marine recreational angling. It does so principally through the Marine Recreational Information Program (MRIP), a survey program that consists of an in-person survey at fishing access sites and a mail survey, in addition to other complementary or alternative surveys. Data collected from anglers through MRIP supply fisheries managers with essential information for assessing fish stocks. In 2006, the National Research Council provided an evaluation of MRIP's predecessor, the Marine Recreational Fisheries Statistics Survey (MRFSS). That review, Review of Recreational Fisheries Survey Methods, presented conclusions and recommendations in six categories: sampling issues; statistical estimation issues; human dimensions; program management and support; communication and outreach; and general recommendations. After spending nearly a decade addressing the recommendations, NMFS requested another evaluation of its modified survey program (MRIP). This report, the result of that evaluation, serves as a 10-year progress report. It recognizes the progress that NMFS has made, including major improvements in the statistical soundness of its survey designs, and also highlights some remaining challenges and provides recommendations for addressing them.
Recent scientific literature has raised many concerns about whether fisheries have caused more extensive changes to marine populations and ecosystems than previously realized or predicted. In many cases, stocks have been exploited far beyond management targets, and new analyses indicate that fishing has harmed other species—including marine mammals, seabirds, sea turtles, and sea grasses—either directly through catch or habitat damage, or indirectly through changes in food-web interactions. At the request of the National Oceanic and Atmospheric Administration, the National Research Council conducted an independent study to weigh the collective evidence for fishery-induced changes to marine ecosystems and the implications of the findings for U.S. fisheries management. Dynamic Changes in Marine Ecosystems provides comprehensive information in regard to these findings.
For an unknown reason, the Steller sea lion population in Alaska has declined by 80% over the past three decades. In 2001, the National Research Council began a study to assess the many hypotheses proposed to explain the sea lion decline including insufficient food due to fishing or the late 1970s climate/regime shift, a disease epidemic, pollution, illegal shooting, subsistence harvest, and predation by killer whales or sharks. The report's analysis indicates that the population decline cannot be explained only by a decreased availability of food; hence other factors, such as predation and illegal shooting, deserve further study. The report recommends a management strategy that could help determine the impact of fisheries on sea lion survival-establishing open and closed fishing areas around sea lion rookeries. This strategy would allow researchers to study sea lions in relatively controlled, contrasting environments. Experimental area closures will help fill some short-term data gaps, but long-term monitoring will be required to understand why sea lions are at a fraction of their former abundance.
This publication reports on the 8th session of the Scientific Advisory Committee (SAC) of the General Fisheries Commission for the Mediterranean, which was held in Tirana, Albania in October 2005. Issues discussed include: fishery management proposals emanating from the work of sub-committees; research priorities and its workplan for 2006; measures for the protection of certain marine ecosystem including gear selectivity issues and stock assessment methodologies.
The Committee examined its work since the First Session, undertook an appraisal of FAO's fisheries research-related programmes and elaborated the Committee's work for the intersessional period (1999-2000).
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