Eliminating duck predation in mussel farms by exclusion nets; development and experimental product testing

Predation from sea-ducks is an increasing problem for the blue mussel industry. Mussel farms constitute an artificial habitat with easily accessible food for several duck species, and large aggregations of birds may, in only a few days, completely empty a mussel farm. A large selection of auditive and visual bird scaring devices, in addition to chemical repellents, is commercially available, but research has proved these methods subject to rapid habituation. The use of exclusion nets is very promising, bu t has so far been costly and has not been subject to scientific testing. These installations also kill both fish and birds, which get entangled in the nets. Norway has a special international management responsibility for seabirds. This project will devel op and test nets and its effekt on seabird behavior. This will lead to the development of an officially endorsed standard, which should be both cost-effective and satisfies environmental management standards. The proposed project will be an international cooperation between Norway and Canada, with important contributions from leading experts on seaducks, and representatives from the mussel industry in both countries. The first part of the project will consist of a study using captive birds in aquarium tan ks where the effect of different net-variants will be tested. In the second part, we will conduct field tests of nets in existing blue-mussel farms, based on the results from the first part of the study.