Spatial structure in length at age of cod in the Barents Sea
Abstract:Cod Gadus morhua population in the Barents Sea was found to be spatially structured with regard to length-at-age. Results were based on data collected during research surveys in the Barents Sea between 1982 and 1997. The identified spatial structure was most pronounced for age groups 2–4 years and decreased for the older age groups with higher potential for migration. A positive linear correlation between mean length-at-age and mean geographical temperature was established for age groups 2–4 years. This correlation was shown to be strongest when based on mean temperatures during 3 year periods ending with the year of capture. The spatial structure in length-at-age was shown to follow the temperature gradient of the Barents Sea. A large part of the observed area effects could be explained by temperature variation between areas. Evidence is also presented which indicates that the predictability and sensitivity of the dependence of length-at-age on temperature increases under extreme environmental conditions, i.e. in the northern and eastern areas of the Barents Sea.
Document Type: Regular Paper
Affiliations: 1: Adaptive Dynamics Network, International Institute for Applied Systems Analysis, A-2361 Laxenburg, Austria, 2: Institute of Marine Research, P. O. Box 1870 Nordnes, N-5187 Bergen, Norway, 3: Norwegian University of Science and Technology, Trondhjem Biological Station, N-7034 Trondheim, Norway
Publication date: 2003-03-01