Â鶹¹ÙÍø

• Franz Mueter
• Alexei Pinchuk

• Early life history ecology of Alaskan groundfish

Following large declines in estimated Gulf of Alaska sablefish biomass, developing methods to improve the sablefish assessment, in particular early estimates of recruitment, are needed to inform management of this economically important fishery. While no reliable spawner-recruit relationship exists for sablefish, previous studies indicate that juvenile growth may be a useful predictor of year-class success. I propose an integrated approach that combines over 20 years of historical field collections, laboratory analyses, and modeling to assess variability in growth of juvenile sablefish. Otoliths are being used to estimate growth at a daily resolution as part of a NOAA Cooperative Â鶹¹ÙÍø Project. I hypothesize that early feeding ecology significantly influences growth and propose to assess relationships between variations in growth and diet composition using stable isotopes, stomach contents, and fatty acid analyses across multiple time scales. In addition, I will test the predictive power of a suite of environmental indices (e.g., Northern Oscillation, Ekman transport, primary productivity, spring prey fields) for juvenile sablefish growth. I intend to use this information to develop environmental and ecological indices of juvenile sablefish growth that can be considered in the stock assessment to reduce uncertainty in estimates of age-2 or age-3 sablefish recruitment.

• Alternative methods of juvenile sablefish sampling

• Â鶹¹ÙÍø FIsheries Scientist, Alaska Fisheries Science Center, Auke Bay Laboratories