00000nam 2200000za 4500 9.805579 CaOODSP 20221107135702 cr ||||||||||| 150406s1999 oncdb ob f000 0 eng d CaOODSP eng eng fre n-cn--- Fs70-1/1999-180E-PDF Evaluation of the 1998 4WX herring acoustic surveys [electronic resource] / G.D. Melvin … [et al.]. Ottawa : Fisheries and Oceans Canada, 1999. 32 p. : fig., graphs, maps, tables. Canadian Stock Assessment Secretariat research document, 1480-4883 ; 99/180 Includes bibliographic references (p. 17). Automated acoustic logging systems installed on commercial herring purse seine boats were used to document the distribution and abundance of herring in NAFO Division 4WX during the 1998 fishing season. As in previous years, data were collected during both fishing operations and structured (science-directed mapping/acoustic) surveys. The number of structured surveys in southwest Nova Scotia decreased from five in 1997 to three in 1998 and most biomass estimates were instead computed from fishing operations. The number of automated systems increased from two to six. Total biomass estimates for a spawning component was determined by summing the surveys and/or fishing estimates of greater than ten days intervals. Biomass estimates for German Bank, Scotia Bay, Trinity Ledge and Spectacle Buoy were 44,700 t, 72,500 t, 6,800 t and 1,300 t respectively. Based on this approach the spawning stock biomass of 4WX herring stock complex was estimated to be 521,300 t, down slightly from 568,500 t in 1997. gccst Fisheries resources gccst Salt water fish gccst Fishing area gccst Fisheries management Melvin, Gary Donald, 1951- Canada. Department of Fisheries and Oceans. Canada. Canadian Stock Assessment Secretariat. Canadian Stock Assessment Secretariat research document, 1480-4883 ; 99/180 (CaOODSP)9.507740 PDF 3.21 MB https://publications.gc.ca/collections/collection_2015/mpo-dfo/Fs70-1-1999-180-eng.pdf