Data on stage-specific abundance of black surfperch,
the amount of foraging habitat and the availability of their food
were collected at 11 fixed locations within 4 sites on the north
shore of Santa Cruz Island, CA in autumn annually from 1993-2009.
At each location, fixed 40x2m transects at 3, 6, and 9 m depth
contours (the typical black surfperch depth range) were surveyed
for black surfperch and their foraging habitat by divers using SCUBA,
and samples were collected to estimate their principal crustacean
food items. Counts of fish distinguished among young-of-year,
juveniles (1 year old) and adults (>= 2 years old).
We defined foraging habitat as the average annual percent cover
of all low-lying turf and foliose algae from which black surfperch
harvest prey (Laur and Ebeling 1983, Holbrook and Schmitt 1984, Schmitt
and Holbrook 1984) across all transects within each site.
Food density was defined as the observed biomass density of prey
(g wet mass m^-2), which included jaeropsid and idoteid isopods,
gammarid and caprellid amphipods and crabs within the adult
black surfperch gape limitation (Schmitt 1984).
Estimates of food density for each site were calculated as in
Okamoto et al. (2012) and include the density of prey sampled from
replicate 0.1 m^2 patches of foraging habitat in each year from
which individual prey were counted and sized. Food biomass was
not normalized by the habitat percent cover on transects (as was
done in Okamoto et al., 2012) so habitat and biomass density of
food could be evaluated independently. Annual means of the biomass
density of food averaged over all sites for each year of the time
series were used as values for food availability in all analyses.
Fish and habitat time series in this dataset are annual site
means while prey time series are annual means across all sites.
Holbrook, S.J. and Schmitt, R.J. (1984). Experimental analyses
of patch selection by foraging black surfperch (Embiotoca jacksoni Agazzi).
Journal of Experimental Marine Biology and Ecology, 79, 39-64.
Laur, D.R. and Ebeling, A.W. (1983). Predator-prey relationships in
surfperches. Environmental Biology of Fishes, 8, 217-229.
Okamoto, D.K., Schmitt, R.J., Holbrook, S.J. and Reed, D.C. (2012).
Fluctuations in food supply drive recruitment variation in a marine fish.
Proceedings of the Royal Society B: Biological Sciences, 279, 4542-4550.
Schmitt, R.J. and Holbrook, S.J. (1984). Gape-limitation, foraging
tactics and prey size selectivity of two microcarnivorous species of fish.
Oecologia, 63, 6-12.