posted on November 01, 1980 10:01
R. K. Mayo
National Marine Fisheries Service, Northeast Fisheries Center
Woods Hole, Massachusetts 02543, USA
Source - Journal of Northwest Atlantic Fishery Science, Volume 1: 21-37
The redfish fishery of the Gulf of Maine-Georges Bank region is reviewed and an assessment of the current status of the stock is presented. Annual nominal catches of approximately 13,000 to 14,000 metric tons in 1977 and 1978 were considerably below the peak annual yield of about 60,000 tons but close to the estimated maximum sustainable yield (MSY) as determined by general production model analyses. However, the level of effort expended during the most recent years was 2 to 3 times higher than the level corresponding to the estimated MSY. Standardized effort calculations indicate that real effort has substantially increased since the mid-1960's due in part to a major shift in the size cornposition of the redfish fleet toward larger, more efficient vessels.
Estimated von Bertalanffy growth parameters are utilized in a yield-per-recruit analysis. For an instantaneous natural mortality rate (M) of 0.10, maximum yield per recruit is achieved at an instantaneous fishing mortality (F) in excess of 1.00 at recruiting ages of 9-10 years. For M of 0.05, the maximum yield per recruit occurs at slightly lower F levels but at considerably higher recruiting ages. The F 01 levels, however, are generally in the range of 0.10-0.20 under both assumptions of M.
Recruitment to the redfish fishery in this region has been extremely variable over the last two decades, and the fishery is becoming increasingly dependant on one or two dominant year classes. Between 1964 and 1978, only the 1971 year-class appeared in the population in significant quantities. This year-class began to account for a considerable portion of the catches in 1976 and 1977 and became fully recruited to the fishery in 1978 at an age when fish were just beginning to mature.
Language - English
Publisher - Northwest Atlantic Fisheries Organization (NAFO), Dartmouth, N.S., Canada
Publication Date - December 1980
Publication Type - Journal Article
Descriptors - Atlantic redfish, catch, Georges Bank, growth, Gulf of Maine, recruitment