October 15, 2010
With decreasing population size of many rockfish species, accurate forecasting of the biomass that recruits to a fishery is needed to adequately manage stocks and set catch quotas.
Since 1983, the Habitat Ecology Team has conducted surveys of juvenile rockfish recruiting to nearshore areas off the coast of northern California. In 2001, when the NMFS Fisheries Ecology Division moved to Santa Cruz, a second sampling site was established at the southern end of Monterey Bay to make comparisons of recruitment timing and magnitude between northern and central California. We estimate the number juveniles that survive their pelagic phase and annual recruitment strength for three rockfish species (blue, yellowtail, and black rockfish). Fishes also are collected to estimate age and growth.
From these long time series, we can better predict rockfish year classes that potentially contribute to the fishery in following years. From these time series along the coast, we develop an index of rockfish recruitment, determine recruitment timing, and evaluate environmental and biological factors that influence recruitment on local and coast-wide scales. Our team coordinates with other subtidal efforts coastwide in an effort to standardize assessment methods and interpret results among all surveys. Tom Laidig also is an expert in identification of juvenile rockfishes and routinely assists other researchers and divers in accurate identification of young rockfises.
Laidig, Thomas E. (2010) Influence of ocean conditions on the timing of early life history events for blue rockfish (Sebastes mystinus) off California. Fishery Bulletin 108(4):442-449.
Laidig, Thomas E., James R. Chess, and Daniel F. Howard. (2007) Relationship between abundance of juvenile rockfishes (Sebastes spp.) and environmental variables documented off northern California and potential mechanisms for the covariation. Fishery Bulletin 105:39-48.
Contact: SWFSC Fisheries Ecology Division, Habitat Ecology Team