Samples taken by various gear from October 1978 to May 1980 indicate that many fish species, some of which are commercially important, utilize the tidal creeks and inland portions of Elkhorn Slough, a shallow coastal embayment in Monterey Bay. California. In order of abundance, fishes important to commercial fisheries were northern anchovy, Pacific herring, shiner surfperch, starry flounder, black surfperch, leopard shark, California halibut, bat ray, and English sole. Most of these species occurred in the tidal creeks and upper slough primarily as juveniles, while individuals of some species were captured in lower numbers as reproductively active adults (Pacific herring, shiner perch, black perch, leopard shark, bat ray). Most species exhibited seasonal patterns of occupation with the highest densities of juveniles occurring in spring and summer; these patterns reflected the reproductive habits of the species. These fishes fed on a variety of prey types, including zooplankton, epifaunal crustacean, infaunal worms and mollusca, and larger mobile crustaceans and fishes. Plant material and detritus constituted a small portion of the diets of most species, but were much less important overall than the above prey types. Although the relative importance of Elkhorn Slough to commercial fish production in Monterey Bay and the California continental shelf is difficult to assess, it appears that shallow turbid areas in Elkhorn Slough function as a nursery and/or spawning area for various economically important fishes. Factors responsible for this utilization may include high primary and secondary production, beneficial temperature and salinity regimes, and relatively low predation pressure due to high turbidity and/or low predator densities.
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