Publication Abstract

Past and present use of reference points for Atlantic salmon

Definition + use of reference points for Atlantic salmon: A review of the approaches of ICES and NASCO

E.C.E. Potter

For more than a decade, the International Council for the Exploration of the Sea (ICES) and the North Atlantic Salmon Conservation Organisation (NASCO) have been working to develop scientific methods and management principles to address the conservation requirements and exploitation demands of salmon in the North Atlantic. The approaches are based upon the use of biological reference points and incorporate new concepts, such as the application of the precautionary approach. NASCO has agreed that conservation limits should be set for all river stocks, defining the level below which numbers of spawners should, ideally, not be permitted to fall. NASCO has favoured a fixed escapement policy, and conservation limits are being set at the stock size that will give maximum sustainable yield (S_MSY), although alternative reference points may be considered. Limits are being determined for stocks for which stock-recruitment relationships can be described and transported to other systems using various habitat models. Conservation limits have been set for a large number of North American Atlantic salmon stocks and collectively for all areas, but many estimates are still based upon standard egg deposition rates and should therefore be regarded as preliminary. Progress in Europe has been slower, reflecting, among other things, the greater number and diversity of salmon stocks and the difficulty of co-ordinating developments between the various salmon producing nations. NASCO has also proposed that stocks should be maintained above their conservation limits by means of management targets, although the procedures for setting these has yet to be established. In many areas, however, the conservation limits are still being used as targets, resulting in a high risk of spawning stocks falling to unacceptably low levels. There is therefore an urgent need to develop methods to incorporate the biological and management uncertainties in these assessments in order to conserve salmon stocks.

Reference:

E.C.E. Potter, 2001. Definition + use of reference points for Atlantic salmon: A review of the approaches of ICES and NASCO.pp194-223 In: (Provost, E and Chaput, G. (eds.)) Stock, recruitment and reference points. Assessment and management of Altantic salmon.INRA - Rennes

ECE Potter*

pp194-223 In: (Provost, E and Chaput, G. (eds.)) Stock, recruitment and reference points. Assessment and management of Altantic salmon.INRA - Rennes