Interannual and Spatial Feeding Patterns of Hatchery and Wild Juvenile Pink Salmon in the Gulf of Alaska in Years of Low and High Survival

Autor: Jennifer L. Boldt, John Piccolo, Nancy D. Davis, Lewis J. Haldorson, Jamal H. Moss, Robert V. Walker, Katherine W. Myers, Janet L. Armstrong, David A. Beauchamp
Rok vydání: 2008
Předmět:
Zdroj: Transactions of the American Fisheries Society. 137:1299-1316
ISSN: 1548-8659
0002-8487
DOI: 10.1577/t07-196.1
Popis: To improve understanding of the mechanisms affecting growth and survival, we evaluated the summer diets and feeding patterns (prey composition, energy density, and stomach fullness) of hatchery and wild juvenile pink salmon Oncorhynchus gorbuscha in Prince William Sound (PWS) and the northern coastal Gulf of Alaska (CGOA). Our study (1999-2004) included 2 years of low (∼3%), mid (∼5%), and high (∼8-9%) survival of PWS hatchery pink salmon. Because variations in diet should affect growth and ultimately survival, we expected that the variations in diet, growth, and survival would be correlated. During August in the CGOA, pteropod-dominated diets and higher gut fullness corresponded to high survival (5-9%), and copepod-dominated diets and lower gut fullness corresponded to low survival (3%). Within years, no significant differences were found in diet composition or gut fullness between hatchery and wild fish or among the four PWS hatchery stocks. Diets varied by water mass (habitat) as juveniles mov...
Databáze: OpenAIRE
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