Juvenile Rockfish Recruitment in Trinidad Bay, California

摘要

This study is the first to describe the relative interannual abundance and timing of nearshore juvenile rockfish, Sebastes spp., recruiting to nearshore kelp beds in Trinidad Bay, California. Recruitment refers to the number of individuals arriving onshore from pelagic larval habitat. Documenting recruitment at new sites may provide insight into coastwide patterns, providing resolution to competing hypotheses that describe why annual recruitment varies. However, recruitment can be patchy along the coast, requiring exploratory research to identify recruitment sites before beginning long-term monitoring. The objective of this study is to provide the first description of the timing and abundance of nearshore juvenile rockfish entering kelp beds in Trinidad Bay. Fish were sampled weekly over the summers of 2010 and 2011 with two artificial reefs, Standard Monitoring Units for the Recruitment of Fishes (SMURFs). The number of fish sampled varied annually, averaging 3,464 (n = 2, SD = 315) fish sampled per SMURF in 2010 and 447 (n = 2, SD = 8) sampled per SMURF in 2011. Of the fish sampled, 46% and 23% were juvenile Black Rockfish S. melanops in 2010 and 2011, respectively. The order in which species arrived onshore was consistent between the years and matched the order of parturition among species. We conclude Trinidad Bay would be a valuable site for long-term monitoring of rockfish recruitment in northern California and discuss our observations within the context of habitat selection, larval transport, and open-ocean survival. Received August 25, 2013; accepted November 6, 2013