Escape-related behavior and coping ability of sea bream due to food supply

Abstract

Escape of fish is a significant problem for the sustainability of the aquaculture industry. In the Mediterranean Sea, sea bream (Sparus aurata) has been reported to escape from sea cage installations. However, the related factors leading to this behavior still remain unknown. This study focuses on the impact that the food supplied to sea bream has on its interaction with the net and therefore its escape behavior. We test three food ratios (2, 1 and 0 % of the total initial body weight; FC2, FC1 and FC0 populations, respectively) and three different conditions of the net (flawless mesh, mesh with a cut twine and mesh with a tear) that are commonly found in aquaculture. Data acquisition and analysis are carried out with a tailor-made system developed in our laboratory for this purpose. We demonstrate that food supply is associated with fish interactions and the aquaculture net, while net condition is also an important stimulus for sea bream inspection and biting the net. Limited-fed fish (FC1) are more prone to interact with the net, which consequently leads them to either bite net wears or escape through tears.