Fluctuation in Stock Properties of Arcto-Norwegian Cod Related to Long-term Environmental Changes

• Main Author: Olav Rune Godø
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2000
• Subjects: Barents Sea; Svalbard
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.33.7518; http://www.iiasa.ac.at/Publications/Documents/IR-00-023.ps

From a historic perspective the cod in the Barents Sea-Svalbard region has been the most productive gadoid stock in the Atlantic. Variation in catches has always been large, but during the last 10-15 years catches and stock abundance have reached the lowest level on record. Three major causes of variation have been discussed; stock reduction through exploitation, environmental influences on recruitment, and species interaction effects on maturation, growth and mortality. In addition, interactions between these three sources might be important. The influence of each specific factor is difficult to evaluate from incidental observations and short-term time series. In that respect, the time series on catches and on biological and environmental information of this stock, which partly goes back to the 19th century, assumes a unique position in comparison with data on most other stocks. In this paper fluctuations in catches and stock abundance will be compared with changes in recruitment.