Download or read book The Factors Affecting the Diets of Groundfish in the Gulf of Alaska written by Kevin A. Thompson and published by . This book was released on 2015 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine systems undergo changes in community composition over time as a result of a variety of environmental and anthropogenic factors. Understanding these community changes and the factors that drive them is critical for ecosystem management of marine resources. The Gulf of Alaska (GOA) is a large marine ecosystem that includes a variety of species that support large scale fisheries. This is also a system in which large scale community shifts, or regime shifts, have occurred due to the Pacific Decadal Oscillation (PDO) and fishing pressure. Given the economic and conservation importance of this marine system, the GOA has been modeled using a variety of multispecies, or ecosystem, models. While this work has been critical in understanding the ecosystem dynamics of the GOA and helped generate management recommendations for commercial species, these models often make assumptions regarding trophic-dynamics, particularly that predator-prey relationships follow a standard functional response and do not change through time in response to environmental variables. However, empirical evidence suggests that a predator's diet can be influenced by a variety of factors, abiotic and biotic, at large and small spatial scales. Our overall objective was to investigate the potential impact environmental variables may have in structuring this ecosystem by using statistical analyses of diets and an ecosystem modeling framework. We focused on three commercially and ecologically important groundfish predators: Pacific Cod (Gadus macrocephalus), Pacific Halibut (Hippoglossus stenolepis), and Sablefish (Anoplopoma fimbria). We also focused on a key prey species, Walleye Pollock (Gadus chalcogrammus), and used environmental data collected during trawl surveys and PDO data generated for the entire North Pacific region. The first study completed was focused solely on the consumption of Walleye Pollock, a critical fishery species and ecosystem link. We used data from trawl surveys to determine the potential influence of local environmental variables on the predation rate of Walleye Pollock in the system by these groundfish. Using an information-theoretic approach, we found that predator length was positively related to Walleye Pollock presence and proportion of total diet weight in all predators. Increased temperatures positively affected consumption of Walleye Pollock by Pacific Halibut, but not the other predators. We found evidence for a number of inter-predator effects of co-occurring predators, both positive (facultative) and negative (competitive). Observed prey density was not statistically significant with respect to consumption for these predators, suggesting that trawls sample the environment differently than Walleye Pollock predators or species interactions are more complex than those used in previous multispecies models. In our second study, we considered the entire diet of these predators, rather than one key prey. Furthermore, because PDO had been described as leading to community changes in the system previously, we hypothesized that it could also be driving shifts in diets in the three groundfish predators we studied. We used a multivariate statistical approach to compare the diets of these predators by PDO state (warm or cold years) and also included local environmental covariates. Overall, we found that diets observed in PDO cold years were significantly different than diets in fish in warm years. In general, predators were found to be consuming more Walleye Pollock and euphausiids in warm years, and more benthic invertebrates and other forage fish in cold years. Local environmental covariates contributed to the diets observed in these predators, however no general pattern was observed. Our results also show the benefit of using diet data from large scale monitoring efforts as indicators of community shifts in a large marine ecosystem through time. Ultimately, we used our statistical analyses regarding diet and PDO state to drive a modeling exercise using alternate representations of the diets of the predators in the GOA. We investigated the potential impact of shifting diets in groundfish in an ecosystem-modeling framework, using Ecopath trophic-mass balance models. We changed the diets of key groundfish predators in the model based on our previous results for three alternative model parametrizations; 1) average conditions over the time period, 2) cold PDO state, and 3) warm PDO state. We noted a number of differences in model estimated ecosystem indices. Biomass accumulation estimates indicated that some ecologically and commercially important species groups would be expected to greatly diverge in population size if models were based on data from warm vs. cold PDO years compared to the averaged climatic state. In general, predator overlap was at its lowest in the cold year model, as predators had more diverse diets and therefore predation was more diffuse in the system in general. These results indicate the potential importance of environmental context when collecting diet data to be used in ecosystem models designed to provide fishery management recommendations. As ecosystem models are used more commonly, taking the time to investigate the factors that structure diets and how predation changes due to environment can yield more representative, and potentially more accurate biomass projections and recommendations for the GOA and likely many other managed marine ecosystems.

Download or read book Fishery Management Plan and Environmental Impact Statement for the Gulf of Alaska Groundfish Fishery During 1978 written by North Pacific Fishery Management Council and published by . This book was released on 1977 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Groundfish Total Allowable Catch Specifications and Prohibited Species Catch Management Plans for the Groundfish Fishery of the Bering Sea and Aleutian Islands Area and Groundfish of the Gulf of Alaska written by and published by . This book was released on 1998 with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alaska Groundfish Harvest Specifications written by and published by . This book was released on 2007 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Draft EIS provides decision-makers and the public with an evaluation of the environmental, social, and economic effects of alternative harvest strategies for the federally managed groundfish fisheries in the Gulf of Alaska (GOA) and the Bering Sea and Aleutian Islands (BSAI). The EIS examines alternative harvest strategies that comply with Federal regulations, the Fishery Management Plans for the GOA and BSAI groundfish fisheries, and the Magnuson-Stevens Act. The harvest strategies are applied to the best available scientific information to derive the total allowable catch for the groundfish fisheries.

Download or read book Food Habits of Groundfishes in the Gulf of Alaska in 1999 and 2001 written by Mei-Sun Yang and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Food habits of the commercially important groundfishes in the Gulf of Alaska in 1990 written by Mei-Sun Yang and published by . This book was released on 1993 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Programmatic Supplemental EIS for Alaska Groundfish Fisheries Implemented Under the Authority of the Fishery Management Plans for the Groundfish Fishery of the Gulf of Alaska and the Groundfish of the Bering Sea and Aleutian Islands Area written by and published by . This book was released on 2004 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Programmatic Supplemental EIS for Alaska Groundfish Fisheries Implemented Under the Authority of the Fishery Management Plans for the Groundfish Fishery of the Gulf of Alaska and the Groundfish of the Bering Sea and Aleutian Islands Area written by and published by . This book was released on 2004 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gulf of Alaska Groundfish Fisheries Management Plan FMP 1978 written by and published by . This book was released on 1977 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fishery Management Plan for the Gulf of Alaska Groundfish Fishery written by North Pacific Fishery Management Council and published by . This book was released on 1979 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: "As directed by the Fishery Conservation and Management Act of 1976 (P.L. 95-265) the North Pacific Fishery Management Council is preparing fishery management plans for those fisheries within its area of jurisdiction. This document was the first of the plans to be completed by the Council since its formation in October, 1976. The Fishery Management Plan for the Gulf of Alaska Groundfish Fishery was developed by a multi-agency team composed of members from the National Marine Fisheries Service, the Alaska Department of Fish and Game, the International Pacific Halibut Commission and the University of Washington. It was approved by the North Pacific Fishery Management Council on September 24, 1977, for submission to the Secretary of Commerce. Regulations to implement this plan were published on the same date. It was approved by the Secretary of Commerce and published in the Federal Register on April 21, 1978. The Plan has been amended seven times, beginning December 1, 1978 (Amendment 1 implemented) and most recently, November 1, 1979 (Amendment 7 implemented). An explanation of these amendments is attached."-- from page 1.

Download or read book Climate Change Impacts on Fisheries and Aquaculture written by Bruce F. Phillips and published by John Wiley & Sons. This book was released on 2017-09-18 with total page 1059 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first comprehensive review of the current and future effects of climate change on the world’s fisheries and aquaculture operations The first book of its kind, Climate Change Impacts on Fisheries and Aquaculture explores the impacts of climate change on global fisheries resources and on marine aquaculture. It also offers expert suggestions on possible adaptations to reduce those impacts. The world's climate is changing more rapidly than scientists had envisioned just a few years ago, and the potential impact of climate change on world food production is quite alarming. Nowhere is the sense of alarm more keenly felt than among those who study the warming of the world's oceans. Evidence of the dire effects of climate change on fisheries and fish farming has now mounted to such an extent that the need for a book such as this has become urgent. A landmark publication devoted exclusively to how climate change is affecting and is likely to affect commercially vital fisheries and aquaculture operations globally, Climate Change Impacts on Fisheries and Aquaculture provides scientists and fishery managers with a summary of and reference point for information on the subject which has been gathered thus far. Covers an array of critical topics and assesses reviews of climate change impacts on fisheries and aquaculture from many countries, including Japan, Mexico, South Africa, Australia, Chile, US, UK, New Zealand, Pacific Islands, India and others Features chapters on the effects of climate change on pelagic species, cod, lobsters, plankton, macroalgae, seagrasses and coral reefs Reviews the spread of diseases, economic and social impacts, marine aquaculture and adaptation in aquaculture under climate change Includes special reports on the Antarctic Ocean, the Caribbean Sea, the Arctic Ocean and the Mediterranean Sea Extensive references throughout the book make this volume both a comprehensive text for general study and a reference/guide to further research for fisheries scientists, fisheries managers, aquaculture personnel, climate change specialists, aquatic invertebrate and vertebrate biologists, physiologists, marine biologists, economists, environmentalist biologists and planners.

Download or read book Food Habits of the Commerically sic Important Groundfishes in the Gulf of Alaska in 1990 1993 and 1996 written by Mei-Sun Yang and published by . This book was released on 2000 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regulatory Impact initial Flexibility Analysis of Proposed Inshore offshore Allocation Alternatives Amendment 18 23 to Groundfish Bering Sea and Aleutian Islands Fisheries Management Plan FMP and Gulf of Alaska Groundfish Fisheries Management Plan FMP written by and published by . This book was released on 1992 with total page 852 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Programmatic Supplemental Environmental Impact Statement for Alaska Groundfish Fisheries Implemented Under the Authority of the Fishery Management Plans for the Groundfish Fishery of the Gulf of Alaska and the Groundfish of the Bering Sea and Aleutian Islands Area Chapter 4 continued written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This programmatic supplemental environmental impact statement was prepared to establish a new baseline of environmental and economic information, bringing the federally managed groundfish fisheries into compliance with the National Environmental Policy Act. Analysis presents the impacts of groundfish fishing on the biological and economic environments that result from a broad array of policy-level programmatic fisheries management alternatives.

Download or read book Programmatic Supplemental Environmental Impact Statement for Alaska Groundfish Fisheries Implemented Under the Authority of the Fishery Management Plans for the Groundfish Fishery of the Gulf of Alaska and the Groundfish of the Bering Sea and Aleutian Islands Area written by United States. National Marine Fisheries Service. Alaska Regional Office and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This programmatic supplemental environmental impact statement was prepared to establish a new baseline of environmental and economic information, bringing the federally managed groundfish fisheries into compliance with the National Environmental Policy Act. Analysis presents the impacts of groundfish fishing on the biological and economic environments that result from a broad array of policy-level programmatic fisheries management alternatives.

Download or read book Programmatic Supplemental Environmental Impact Statement for Alaska Groundfish Fisheries Implemented Under the Authority of the Fishery Management Plans for the Groundfish Fishery of the Gulf of Alaska and the Groundfish of the Bering Sea and Aleutian Islands Area Appendix A continued Appendix B written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This programmatic supplemental environmental impact statement was prepared to establish a new baseline of environmental and economic information, bringing the federally managed groundfish fisheries into compliance with the National Environmental Policy Act. Analysis presents the impacts of groundfish fishing on the biological and economic environments that result from a broad array of policy-level programmatic fisheries management alternatives.

Download or read book NOAA Technical Report NMFS written by and published by . This book was released on 1984 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: