The daily feeding dynamics in various length groups of the Barents Sea capelin

Abstract

A total of 692 capelin stomachs collected in the Goose Bank area in August 1989 by 24 hour fishery were analyzed by 3 cm capelin length groups. The nwnber of prey categories consumed by the Barents Sea capelin showed a tendency to increase with increasing fish length up to 12 cm. Calanus finmarchicus was the major contributor in the diet (66.4 % of total stomach weight) of length group 6-8.9 cm. Capelin in length group 9-11.9 cm had mainly fed on Calanus finmarchicus (33.5 %), Parathernisto abyssorum (14.5 %) and Thysanoessa raschii (28.0 %) while the two species Thysanoessa inermis and Thysanoessa raschii occupied 95.2% of the stomach content weight in length group 12-14.9 cm. The feeding seemed to have a peak in the evening and a minimum during the midday for all length groups. The daily ration during this period is estimated to between 1.3 and 2.2 % of fish body weight. Accordingly, these data gives between 3640 and 6160 tonnes as the daily consumption of zooplankton by the capelin stock in the Goose Bank area.