Recent changes in the stock of Celtic Sea herring (Clupea harengus L.)

Abstract

International catches of Celtic Sea herring during the years 1966–70 averaged about 30000 tons/year. This average was considerably above previous estimates for the maximum sustainable yield of this stock. A new assessment of the Celtic Sea herring stock has been made, using information on samples from Dutch catches during the years1958–71. High catches in the years 1966–70 were caused primarily by an increased fishing effort, resulting in an accelerated depletion of older age groups. The increase in catch due to this cause will be mainly temporarily. A second reason for high catches during this period was an increase in level of recruitment by about 50%.