Journal of Aquaculture Research & Development

Design and impact of eco-friendly and practical solutions to excluding predatory birds and diving ducks from cultured mussel lines and shrimp ponds

International Conference on Aquaculture & Fisheries

July 20-22, 2015 Brisbane, Australia

John C Bonardelli

Posters-Accepted Abstracts: J Aquac Res Development

Abstract:

Shellfish production has been increased since the 80s, along with some innovative improvements in technology to match. In particular, mussel longline and shrimp pond culture are volume products well suited for extensive areal expansion, which in turn provides attractive opportunities for birds that prefer this abundant high density prey. Until now, eco-friendly exclusion methods wereunknown and seabird predation has been on the rise with established mussel farms literally gobbled up by diving ducks within weeks, leading to permanent closures, as witnessed in Scandinavia, UK and Canada. Large scale shrimp farms have been increasingly predated on by thousands of birds leading to increased risk of disease transmission, higher production and feed costs, and expensive deterrents requiring vigilance and maintenance. While conventional acoustic methods, firearms and boats have temporary effects on scaring birds, mussel growers who installed submerged nets to surround large offshore sites have either been successful or been convicted for using the wrong mesh type. A scientific approach to designing nets based on eider duck behavior was the spark for a Norwegian-Canadian investigation into predation under controlled settings. Eiders select mussels by size and quality with a preference for cultured over wild, and could be excluded with the right mesh or a spiked grow-out rope. In parallel, an innovative laser light is proving to be an effective eco-friendly deterrent to birds feeding on mussels and shrimp. These three solutions are explored as practical solutions to reducing bird predation on mussel and shrimp farms, with potential application to other species.