December 9, 2010
With support from NOAA’s Fisheries and the Environment (FATE) program, we are pursuing two complementary efforts focused on development of environment-recruitment indices suitable for inclusion in assessments for several rockfish (Sebastes spp.) stocks. First, we are extracting age and growth-increment data from otoliths of pelagic juvenile rockfish collected off central California for the past 25 years, and analyzing the resulting data to quantify how environmental conditions affect growth (and presumably survival) of rockfish early life history stages. Results from this analysis are being used to tailor an individual-based model for fish early life history stages (ELHS) to better mimic dynamics that underpin growth and survival of larval and juvenile rockfishes. Second, using the Regional Ocean Modeling System (ROMS) we are developing coupled bio-physical models for the coastal ocean and plankton ecosystem north of Point Conception, forcing these models with observed winds and other environmental conditions during the winter-spring period that spans parturition and early life history of several economically and ecologically important rockfish stocks, and using IBMs for rockfish ELHS to calculate the integrated recruitment response to environmental forcing. This work is being pursued with colleages in the Groundfish Analysis Team of the Fisheries Ecology Division and at UCSC, and presently supports a graduate students in both the Department of Fisheries Biology and the Environmental Systems Graduate Program in Mathematical Modeling at Humboldt State University.
Contact: SWFSC Fisheries Ecology Division, HSU Cooperative Fisheries Oceanography Research Team