Diet estimation in California sea lions, Zalophus californianus

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Sweeney, J. M., & Harvey, J. T. (2011). Diet estimation in California sea lions, Zalophus californianus. Marine Mammal Science, 27(4), E279-E301. doi:10.1111/j.1748-7692.2010.00459.x
TitleDiet estimation in California sea lions, Zalophus californianus
AuthorsJ. Sweeney, J. Harvey
AbstractWe performed a captive feeding experiment using California sea lions to assess biases associated with estimating pinniped diet using scats and spews. Sea lions were fed nine of their natural prey species: anchovy, sardine, Pacific mackerel, jack mackerel, hake, steelhead smolts, shortbelly rockfish, pink salmon, and market squid. Recovery percentages varied among prey species using otoliths and were improved for adult salmon and sardine using the all-structure method. Numerical and graded length correction factors provided better estimates of number and size of prey consumed. Four models used to determine the proportions of prey species consumed by a sea lion population were tested. The all-structure method and variable biomass reconstruction model, in conjunction with numerical and graded length correction factors, provided more accurate estimates than without. We provide numerical correction factors for all prey species, including correction factors for specific salmon bones: vertebrae, branchials, radials, teeth, gill rakers, and hypurals. © 2011 by the Society for Marine Mammalogy.
JournalMarine Mammal Science
Start pageE279
End pageE301
Subjectsadult, bone, captive population, correction, diet, marine ecosystem, numerical model, otolith, pinniped, prey size, radical, tooth, Cephalopoda, Engraulidae, Oncorhynchus gorbuscha, Oncorhynchus mykiss, Otariidae, Pinnipedia, Rexea solandri, Salmonidae, Scomber japonicus, Sebastes jordani, Zalophus, Zalophus californianus
NoteCited By (since 1996):2, Marine Mammals, Birds & Turtles, CODEN: MMSCE