Atlantic cod predation on redfish in Flemish Cap

Abstract

The aim of this study is to estimate the predation on redfish by Atlantic cod in Flemish Cap in the period 2000- 2010 and the impact of the cod stock recovery in recent years on the prey stock. Atlantic cod samples of stomach contents were taken in the Flemish Cap survey (NAFO Div. 3M). The analysis was done jointly from all individuals, undifferentiated sexes. They were established four size groups of Atlantic cod with a different predation rate on redfish: less than 30 cm, 30-59 cm, 60-79 cm and ≥80 cm. Results show a clear increasing trend in the daily consumption of redfish by cod since 2005. Cod less than 30 cm (one year old) does not consume redfish. Cod with lengths more than 30 cm presents an increasing trend in the quantity of the redfish preyed in the analyzed period. This trend is more evident in the cod more than 60 cm, ages older than 5 years old. Redfish more than 27 cm (older than 8 years old) does not appear in the cod diet. Redfish estimated biomass consumed by total cod biomass is higher than redfish biomass estimated in the last approved assessment disappeared by natural mortality in the period 2000-2005.