Transactions of the American Fisheries Society 133:559–567, 2004 American Fisheries Society 2004 Marine Subsidies in Freshwater: Effects of Salmon Carcasses on Lipid Class and Fatty Acid Composition of
Abstract.—Returning adult salmon represent an important source of energy, nutrients, and bio-chemicals to their natal streams and may therefore have a quantitative effect on the energy levels of stream-resident salmonids. We tested this hypothesis by constructing simulated streams for coho salmon On...
Main Authors: | , , , , , , , , , |
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Format: | Text |
Language: | English |
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.537.3787 http://fisheries.btc.ctc.edu/Enhancement/Marine_subsidies2004.pdf |
Summary: | Abstract.—Returning adult salmon represent an important source of energy, nutrients, and bio-chemicals to their natal streams and may therefore have a quantitative effect on the energy levels of stream-resident salmonids. We tested this hypothesis by constructing simulated streams for coho salmon Oncorhynchus kisutch to which we added 0, 1, and 4 carcasses/m2 (0, 0.71, and 2.85 kg wet mass/m2) of pink salmon O. gorbuscha. After 60 d we evaluated the lipid class and fatty acid composition of rearing coho salmon from the simulated streams; the lipid content and triacylgly-cerols of the coho salmon increased with increasing carcass density whereas phospholipids de-creased. Increased amounts of triacylglycerols accounted for most of the lipid increase. In addition to increasing in concentration, the fatty acid composition of the triacylglycerols also changed with carcass density. Triacylglycerols of juvenile coho salmon from the control streams had significantly higher omega-3: omega-6 ratios as a result of fivefold and sixfold increases in the concentrations of eicosapentanoic and docosahexanoic fatty acids, respectively. These data demonstrate an im-mediate nutritional benefit resulting from the introduction of salmon carcasses in juvenile coho salmon rearing habitat and indicate the utility of fatty acid and lipid class analysis for examining the effects of marine-derived nutrients on juvenile salmonids. |
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