Estimating linkages between redfish and cold water coral on the Norwegian Coast

The importance of essential fish habitat in supporting commercial fisheries has received increasing attention in recent years. Bottom trawling is known to cause particularly destructive damage to habitat that is effectively non-renewable, such as cold water corals. This paper applies the production function approach to estimate the link between cold water corals and redfish in Norway. Both the carrying capacity and growth rate of redfish are found to be functions of cold water coral habitat and thus cold water corals can be considered an essential fish habitat. The paper also estimates a facultative relationship between cold water coral and redfish stocks. The essential habitat model shows the best fit to the data. Comparative statics of an essential habitat indicate an approximate annual loss in harvest of between 11 and 29% within the bounds of coral decline estimated by scientists. In terms of policy, our results indicate that essential fish habitat protection should be considered when managing commercially important species.