00000nam 2200000zi 4500 9.876224 CaOODSP 20221107164641 m o d f cr |n||||||||| 190712s1980 nscab #ob f000 0 eng d CaOODSP eng rda CaOODSP eng fre n-cn-ns Fs70-8/80-31E-PDF Clay, Douglas, 1948- Variability in abundance of Atlantic redfish derived from Canadian summer groundfish surveys on the Scotian Shelf (1970-1979) / Douglas Clay. Dartmouth, Nova Scotia : Marine Fish Division, Bedford Institute of Oceanography, [1980] 1 online resource (41 pages) : illustrations, map. text txt rdacontent computer c rdamedia online resource cr rdacarrier CAFSAC research document ; 80/31 "Not to be cited without permission of author." Includes bibliographical references (pages 11-12). "Redfish (Sebastes marinus mentella) were shown to have had a variable catch history ranging from 84,000 tonnes in 1951 to 12,000 tonnes in 1979. Abundance (or catch rate) was affected by depth with peaks in catch rate at 150, 250 and 350 meters; by bottom temperature with a peak of 6°C; and by time of day with peaks at 1200 and 2130 hrs. Length frequencies from research vessel catches show small fish (<15 cm) to be very rare, although present in occasional catches (indicating their catchability). this lack of apparent recruitment over the last decade and the dependence of the fishery on 1 or 2 age groups (+30% of catch made up of 15 and/or 16 year olds) indicates an unhealthy fishery which requires careful management. A summary of 10 years of R/V survey data is provided"--Abstract. Includes abstract in French. gccst Fish gccst Surveys Canada. Department of Fisheries and Oceans. Scotia-Fundy Region. Marine Fish Division‏. Bedford Institute of Oceanography. CAFSAC research document (Canadian Atlantic Fisheries Scientific Advisory Committee) 80/31 (CaOODSP)9.869616 PDF 1.81 MB https://publications.gc.ca/collections/collection_2019/mpo-dfo/Fs70-8-80-31-eng.pdf