Fine-scale distributions of planktonic fish eggs in the vicinities of Big Sycamore Canyon and Vandenberg Ecological Reserves, and Anacapa and San Miguel Islands, California

Nearshore ichthyoplankton surveys were conducted during late winter and ear ly summer 1998, at four sites in southern California: Big Sycamore Canyon a nd Vandenberg Ecological Reserves, and Anacapa and San Miguel Islands. A co ntinuous underway fish egg sampler (CUFES) was used to sample along each of three or four transect lines oriented alongshore and spaced at about 0.8 k m or 1.6 km intervals offshore, and a bongo net nas towed vertically throug h the water column at a series of stations spaced about 0.8 km or 1.6 km ap art on each line. A total of 41 fish egg taxa and an unidentified fish egg category were coll ected: 30 taxa in winter and 29 in summer. Winter fish egg collections were dominated by northern anchovy; California halibut, speckled sand-dab, whit e croaker, and Pacific hake eggs also were common. Summer egg catches were more evenly distributed over several taxa, primarily senorita, California s heep-head, California barracuda plus white seabass, and speckled sanddab, a s well as unidentified eggs. Collections of eggs in early developmental sta ges suggested that many taxa spawned at night. Senorita spawned during the day, California sheephead probably spawned primarily during the day, and Ca lifornia halibut may have begun spawning during the afternoon and continued into the evening. Both frequency of occurrence and abundance of eggs tended to be higher insh ore and were much reduced on the most seaward line for the more common shor efrsh taxa. White croaker and California sheephead probably spawned primari ly shoreward of about the 30 m isobath, and speckled sanddab and senorita s horeward of about the 60 m isobath. California halibut apparently spawned p rimarily between about the 40 and 60 m isobaths, and California barracuda a nd white seabass spawned over a broader depth range, about 45-90 m. Abundan ces of California halibut and white croaker eggs were highest at the Big Sy camore Canyon site, while the islands, especially Anacapa Island, were impo rtant sites far California sheephead, senorita, California barracuda, and w hite seabass spawning. The CUFES proved to be an effective sampler for fine-scale distributions of planktonic fish eggs, but may inadequately sample taxa or developmental st ages whose vertical distributions are centered above or below its intake de pth. Use of another sampler that covers the entire vertical range of the ta xa of interest is a necessary adjunct to CUFES sampling.