Download or read book The Steller Sea Lion Eumetopias Jubatus Decline and the Gulf of Alaska Bering Sea Commercial Fishery written by Daniel Reneau Hennen and published by . This book was released on 2004 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Steller sea lion (SSL) population in Alaska was listed as threatened under the Endangered Species Act in 1991. Several procedural restrictions were placed on the commercial fisheries of the region at that time in an effort to reduce the potential for human induced mortality on sea lions. Several years have elapsed since these restrictions were put into place and questions about their efficacy abound. In an effort to determine whether or not fisheries interventions have helped the SSL population to recover, estimates of the fishing activity of the Bering Sea/Gulf of Alaska commercial fisheries in the vicinity of individual Steller sea lion rookeries and SSL population trends at those rookeries were made using data from the National Marine Fisheries Service (NMFS) Fisheries Observer Program and Steller Sea Lion Adult Count Database. Fisheries data from 1976-2000 were analyzed in relation to SSL population counts from 1956-2001, at 32 rookeries from the endangered western stock. Linear regression on the principal components of the fisheries data show that a positive correlation exists between several metrics of historical fishing activity and SSL population decline. The relationship is less consistent after 1991, supporting a hypothesis that fishing closures around some of the rookeries have been effective in moderating the localized effects of fishing activity on SSL.

Download or read book Decline of the Steller Sea Lion in Alaskan Waters written by National Research Council and published by National Academies Press. This book was released on 2003-05-04 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Decline of the Steller Sea Lion in Alaskan Waters written by National Research Council and published by National Academies Press. This book was released on 2003-04-04 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book A Review of Proposed Fishery Management Actions and the Decline of Steller Sea Lions Eumetopias Jubatus in Alaska written by Morgen Crow and published by . This book was released on 2001 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recovery Plan for the Steller Sea Lion Eumetopias Jubatus written by and published by . This book was released on 1992 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Steller Sea Lion Protection Measures written by and published by . This book was released on 2001 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recovery Plan for the Steller Sea Lion Eumetopias Jubatus written by and published by . This book was released on 1994 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Harvest of the Steller Sea Lion in Alaskan Waters written by Fredrik V. Thorsteinson and published by . This book was released on 1961 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Steller Sea Lions Eumetopias Jubatus written by Andrew W. Trites and published by . This book was released on 1998 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the changes in the Steller sea lion's diet over time (from a diverse diet including fatty fishes to one dominated by pollock), which has resulted in negative reproductive and survival consequences

Download or read book Aerial and Land based Surveys of Steller Sea Lions Eumetopias Jubatus in Alaska June and July 1999 and 2000 written by John L. Sease and published by . This book was released on 2001 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Relationship of the Foraging Ecology of Steller Sea Lions Eumetopias Jubatus to Their Population Decline in Alaska written by Richard Merrick and published by . This book was released on 1995 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oversight Hearing on Steller Sea Lions written by United States. Congress. House. Committee on Resources. Subcommittee on Fisheries Conservation, Wildlife, and Oceans and published by . This book was released on 2001 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proposed Regulations to Designate Critical Habitat for the Steller Sea Lion Eumetopias Jubatus AK CA OR WA Environmental Assessment EA written by and published by . This book was released on 1993 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Steller Sea Lion Decline written by Douglas P. DeMaster and published by . This book was released on 2002 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most likely cause of the moderate decline of western Alaska Steller sea lions, in the 1990s, is poor recruitment (reproduction and survival of young). Also implicated are nutritional stress, predation, and disease. In contrast, nutritional stress alone was the leading hypothesis for a steep decline in sea lions the 1980s. This book has 13 extended abstracts presented at a May 2001 workshop. Attendees included the nation's leading authorities on Alaska's Steller sea lions.

Download or read book Steller Sea Lion Research written by I. L. Boyd and published by . This book was released on 1995 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerial and Ship based Surveys of Steller Sea Lions Eumetopias Jubatus in Southeast Alaska the Gulf of Alaska and Aleutian Islands During June and July 1991 written by Richard L. Merrick and published by . This book was released on 1992 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oversight Hearing on Steller Sea Lions written by United States. Congress. House. Committee on Resources. Subcommittee on Fisheries Conservation, Wildlife, and Oceans and published by . This book was released on 2001 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: