Self-pollution by Scottish salmon farms?

Abstract

A study of 57 salmon farms in Scotland has shown that acute organic enrichment, usually accompanied by sediment outgassing, occurred beneath most cages. Development of these conditions is considered likely to result in ‘self-pollution’ of the fish farm. A relationship between the seabed type, water depth, water movement, and the intensity of organic enrichment was observed. Site selection guidelines are suggested for reducing the risk of ‘self-pollution’ and these are compared with those used by the fish farm industry elsewhere. The long seabed recovery time found at sheltered sites emphasizes the importance of site selection and also indicates that some site management practices may need modifying.