About the Groundfish Analysis Team
The Groundfish Analysis Team supports essential needs of the National Marine Fisheries Service (NMFS) and the Pacific Fishery Management Council (PFMC) for information on groundfish. Team members have actively participated on the PFMC Groundfish Management Team, since its inception in 1977, and over the years have made many significant contributions in the form of stock assessments, development of new methods, evaluation of alternative management procedures, and collection and processing of important data on fisheries.
The Groundfish Analysis Team is divided into two overlapping sub-teams, one focusing on stock assessments, and the other focusing on surveys and fishery-oceanography.
The Stock Assessment Team has provided many assessments of important groundfish stocks including:
The Team also has collaborated on numerous other recent stock assessments, including
Team members also provide support for the California Cooperative Port Sampling Program with the California Department of Fish and Game and Pacific States Marine Fisheries Commission. Because it is very difficult to estimate rockfish population size with traditional adult trawl and hydro-acoustic surveys, the Fishery-Oceanography Team conducts studies on new approaches to obtain fisheries independent information needed for the assessment models.
The Team has developed a recruitment index for rockfish. Beginning in 1986 standardized annual midwater trawl surveys have been conducted aboard the National Oceanographic Atmospheric Administration (NOAA) research vessel David Starr Jordan to provide information on the abundance and distribution patterns of young-of-the-year (YOY) pelagic juvenile rockfish off central California. Since it takes several years for rockfish to reach catchable size, sufficient data are just becoming available from fishery statistics to examine correlations between the recruitment indices and actual recruitment to the fishery. The team has used the indices in previous assessments of rockfish and found them to be a provocative source of fishery independent information on recruitment.
Results of the YOY surveys show marked interannual fluctuations in abundance and a complex pattern in the spatial distribution of pre-recruits of important species such as bocaccio, widow rockfish, and chilipepper. An understanding of the causes of this variety would aid management by providing insight in developing predictive models. Staff members have collaborated with the Pacific Fisheries Environmental Laboratory in Monterey to study relationships between interannual differences in abundance and spatial distribution of YOY rockfish and the physical environment. The staff has used data from conductivity-temperature-depth (CTD) casts, estimates of currents from acoustic Doppler current profiler (ADCP) tracts, advanced very high resolution radiometer (AVHRR) satellite images, upwelling indices, sea level heights, and National Data Buoy Center moored buoy data for this work.
The team has also worked on development of a method to assess adult biomass by estimating daily larval production by a stock from larval surveys and daily larval production per adult from examination of gonads. One or two more research surveys are needed before design of a production survey is feasible.
Cruise instructions for the 2013 Rockfish Recruitment and Ecosystem Assessment Survey