Use of rocky intertidal areas by juvenile Sebastes in northern California

Juvenile black rockfish, Sebastes melanops, primarily recruit to the nearshore waters of northern California and Oregon. However, their temporary residence in rocky intertidal areas has received little attention. This study examined recruitment and feeding habits of juvenile black rockfish at three rocky intertidal locations in northern California from 2003 to 2005. Juveniles were noted in the rocky intertidal from May through August with peak abundances occurring in May or June. Residency time within the rocky intertidal ranged from 29 to 100 days, depending on location. Interannual variation in recruitment was strongly evident. Relative abundances in 2004 for the three locations sampled were four and nine times greater than the abundances observed in 2003 and 2005, respectively. Variation in fish abundance among sites was also observed over the three year period. Gut analysis showed that juvenile black rockfish consume a wide variety of prey items while in the rocky intertidal. However, Index of Relative Importance values suggest that among the various prey consumed, harpacticoid copepods and gammaridean amphipods are the prey most often taken. This study suggests that rocky intertidal areas are important nursery habitats for juvenile black rockfishes in northern California.