Groundfish Assessment, Regional Planning: Pacific Ocean Perch, Other Rockfish, Lingcod and English Sole Tagging, and Shrimp Abundance - By-Catch Studies

摘要

Major activities during October 1977 to October 1979 included participation and analysis in parts of two major rockfish surveys in cooperation with other State agencies and the National Marine Fisheries Service (NMFS); English sole (Parophrys vetulus) and lingcod (Ophiodon elongatus) tagging in PMFC Areas 2B and 2C off Oregon, and pink shrimp (Pandalus jordani) abundance and bycatch work. Primary objective of rockfish surveys was stock assessment. Goals were to (1) assess abundance and distribution of important rockfish species, (family Scorpaenidae) especially Pacific Ocean perch (Sebastes alutus) in the INPFC Columbia and Vancouver areas; (2) determine change in precision of 1977 and 1979 biomass estimates caused by stratification of sampling units and allocations of sample stations (tows); and (3) to determine whether additional option tows based on vessel captains' experience and knowledge of grounds had any significant effect on the biomass estimate. Secondary objectives were to determine age and size composition of Pacific Ocean perch and determine species composition of slope rockfish in the same area. This report summarizes results of these activities.