Author : Michael Morgan Byerly
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (135 download)
Book Synopsis Groundfish Population Trends from the Prince William Sound Bottom Trawl Survey, 1991 to 2015 by : Michael Morgan Byerly
Download or read book Groundfish Population Trends from the Prince William Sound Bottom Trawl Survey, 1991 to 2015 written by Michael Morgan Byerly and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the groundfish catch from the Prince William Sound bottom trawl survey conducted from 1991 to 2015. Although the purpose of the trawl survey is to assess Tanner crab Chionoecetes bairdi abundance, many groundfish species are also captured, thus providing opportunities to examine population and biological trends over the time series. The catch composition for all species is first characterized at the taxonomic class level and then for fish species at the family level. Time series are then presented for biomass estimates, biological data trends, and spatial trends in CPUE for select commercial and recreationally harvested groundfish species, including rougheye and blackspotted rockfish Sebastes aleutianus and S. melanostictus, Pacific cod Gadus macrocephalus, walleye pollock G. chalcogrammus, sablefish Anoplopoma fimbria, longnose skate Raja rhina, big skate Beringraja binoculata, and Bering skate Bathyraja interrupta. Relatively precise biomass estimates were obtained for most species, although precision was more variable for Pacific cod and sablefish. Following a decline in the early 1990s, rougheye/blackspotted rockfish biomass has remained relatively stable since 1997, fluctuating at or below the long-term average, whereas walleye pollock displayed a more pronounced cyclic trend. Biomass estimates for all skate species have increased since 2007. Biomass estimates were also contrasted with those from the National Oceanic and Atmospheric Administration, Gulf of Alaska bottom trawl survey. Similarities in relative biomass trends between Prince William Sound and the Gulf of Alaska were evident for all species at varying degrees.