Publication Abstract

A re-examination of the relationship between cod recruitment and Calanus finmarchicus in the North Sea

K.M. Brander

Recruitment of cod and other gadoid species was high during the late 1960s and the 1970s and declined throughout the 1980s. This so-called "gadoid outburst" has been ascribed by Cushing (1984) to changes in the abundance and timing of peak occurrence of Calanus finmarchicus in the northeastern North Sea. Continuous Plankton Recorder (CPR) data for that area show no marked trends in abundance and timing during the period 1958-1990, and the multiple regression proposed by Cushing does not model observed variability in cod year classes. Since cod spawn over much of the North Sea and their larvae feed on a range of sizes and species of copepod, a more complete model of the relationship between their abundance and the survival of cod larvae is needed. The CPR may provide some of the extensive population data on copepods which would be required for such a model.

Reference:

K.M. Brander, 1992. A re-examination of the relationship between cod recruitment and Calanus finmarchicus in the North Sea. ICES Marine Science Symposium, 195: 393-401.