Proceedings of the California Academy of Sciences (1981)


General food habits are discussed for 11 species of small marine mammals beach-east in northern California. The collection method allowed tabulation only of the kinds, numbers, and percentages of fish, molluscan, and crustacean prey.
Dominant food species for all male Zalophus californianus were the following: Merluccius productus (62.8 percent of occurrence), Engraulis mordax (23.8 percent), Scorpaenidae (6.3 percent), Porichthys notatus (3.2 percent). Octopus and Loligo also occurred in 7 (23.0 percent) of 30 California sea lions examined.
Nine of 19 individuals of Eumetopias jubatus contained food remnants of fish; 10 new dietary items are reported. Seven of the nine also fed on invertebrates, including four kinds of cephalopods. Scorpaenidae 31.2 percent of occurrence), Merluccius productus (21.7 percent), Pleuronectidae (17.3 percent), and Chilara laylori (11.8 percent) were the principal fishes identified.
Eight of 12 Phoca vitulina stomachs contained food (6 with fish, 2 with invertebrates). Embiotocids (41.9 percent of occurrence), Lycodopsis pacifica (27.9 percent), Pleuronectidae (9.3 percent), and Hexagrammos decagrammus (9.3 percent) were the dominant fishes. The only cephalopod identified from Phoca was Octopus.
The stomachs of all seven individuals of Lagenorhynchus ohliquidens examined contained food. Osmerid fishes, Porichthys, and juvenile rockfishes were the most frequent items identified. The presence of five genera of cephalopods suggests that Lagenorhynchus can take a wide variety of prey from several habitats.
Juvenile Scorpaenidae, Engraulis, Merluccius, and Microgadus made up 97 percent of the diet of 20 individuals of Phocoena phocoena. The abundant cephalopod Loligo was a primary invertebrate food item and was ingested whole.