Estimation of predation mortalities on capelin using a cod - capelin model for the Barents Sea

Abstract

The Barents Sea capelin stock collapsed during the period 1983-1986. One of the main factors causing the collapse was a rapid increase in consumption of capelin by cod. Based on measurements of stomach evacuation rates in the appropriate temperature interval and data from a combined Soviet-Norwegian stomach sampling programme, predation mortalities are calculated by a simplified version of the IMR multispecies model for the Barents Sea - MULTSPEC. Cod-capelin interaction parameters and migration parameters for capelin in MULTSPEC are also estimated. The use of the predation mortalities calculated from the multispecies model in a single-species model used for capelin management is discussed.