Home range and habitat utilization of adult California sheephead, Semicossyphus pulcher (Labridae), in a temperate no-take marine reserve

摘要

The California sheephead, Semicossyphus pulcher Ayres (Labridae), is a carnivorous, temperate, rocky-reef/kelp-bed species that is highly sought in recreational and commercial fisheries. Fine-scale acoustic telemetry tracking was used to ascertain the home range and habitat utilization of S. pulcher. Sixteen adult S. pulcher (26-38 cm SL) were surgically fitted with small acoustic transmitters and manually tracked for up to 144 h during multiple, 24-h periods between March 2001 and August 2002 within the Catalina Marine Science Center Marine Life Reserve (33 degrees 26'N; 118 degrees 29'W). A geographic information system was used to calculate home range sizes (95% kernel utilization distributions) and habitat use. Tracking of the first five fish over 24 h confirmed that S. pulcher were strictly diurnal, so the remaining 11 fish were tracked from 1 h before sunrise to 1 h after sunset. Home ranges varied greatly, from 938 to 82,070 m(2), with a mean (+/- SD) of 15,134 +/- 26,007 m(2). Variability in home range sizes among fish was attributed to differences in habitat shape (embayment vs. contiguous coastline) and to natural habitat boundaries (deep, sandy expanses) in adjacent areas within the reserve. There was a significant relationship between fish length and proportion of time spent in different habitats (sand vs. reef). S. pulcher were found within rocky-reef areas 54% of the time, and, within these areas, a greater percentage of daytime was spent in high-relief areas. Based on the relatively small size and persistence of home ranges of adult S. pulcher, no-take reserves, if they contain appropriate habitat, would provide adequate protection for their stocks.