© 2006 International Council for the Exploration of the Sea
Monitoring the incidence of escaped farmed Atlantic salmon, Salmo salar L., in rivers and fisheries of the United Kingdom and Ireland: current progress and recommendations for future programmes
a Centre for Fisheries and Aquaculture Science Pakefield Road, Lowestoft, Suffolk NR33 0HT, England, UK
b FRS Freshwater Laboratory Faskally, Pitlochry, Perthshire PH16 5LB, Scotland, UK
c Department of Agriculture and Rural Development (DARD), Agriculture and Food Science Centre Newforge Lane, Belfast BT9 5PX, Northern Ireland, UK
d Marine Institute Abbotstown Laboratory Complex, Snugboro Road, Abbotstown, Dublin 15, Ireland
e National Fisheries Technical Team, Environment Agency, Institute of Environmental Science, University of Bangor Robinson Building, Deiniol Road, Bangor, Gwynedd LL57 2UW, Wales, UK
*Correspondence to A. M. Walker: tel: +44 1502 524351; fax: +44 1502 526351. e-mail: alan.walker{at}cefas.co.uk.
An inevitable consequence of the development of the Atlantic salmon, Salmo salar L., farming industry in coastal waters of the British Isles has been the loss of farmed salmon to the wild, their occurrence in inshore waters and rivers, and their appearance in coastal and freshwater fisheries. Monitoring programmes have been developed throughout the British Isles, variously using scientific sampling, catch records from coastal or freshwater fisheries or both, and scientific sampling of catches from in-river traps. We compare the results of these monitoring programmes with regional production and the numbers of escapees reported from marine fish farms. We also consider the effectiveness of the programmes for assessing the prevalence of farmed salmon that escape from marine cages. Finally, we make recommendations for improvements to these programmes and for the development of best practice, including the scientific sampling of in-river spawning stocks through fishery-independent sources, identification of fish origin based on at least two methods, assessment of the degree of incorrect classification, and the timely and accurate reporting of all escapes.
Keywords: aquaculture, Atlantic salmon, escapee, monitoring programmes, stock assessment, wild stocks
Received 28 October 2005; accepted 15 April 2006.