Policy on the Introduction and Transfer of Salmonids

The conclusions of the Department of Fisheries and Oceans Scientific Review Committee were recently presented at the Atlantic Salmon Advisory Committee meetings hosted by Fisheries and Oceans in Montreal.

The conclusions are as follows;

1. Are wild populations of AS (Atlantic salmon) genetically differentiated?
   Conclusion : Wild populations of AS are genetically differentiated
2. Does adaptive genetic variation exist among salmon populations?
   Conclusion : There are important genetically controlled adaptive differences among salmon populations
3. Are there genetic differences between wild and domesticated AS?
   Conclusion : Genetic differences have been observed between wild and cultured salmon with the largest differences expected to be observed between domesticated salmon from Europe or Iceland and wild salmon in North America.
4. Can wild and domesticated salmon interbreed?
   Conclusion : Wild and domesticated AS can interbreed, and in some cases escaped domestic salmon can form the majority of fish in the spawning population.
5. If wild and domesticated salmon interbreed, what is the impact?
   Conclusion : There is no evidence to indicate that interbreeding between wild and domesticated salmon will be beneficial to the wild population. There is evidence to indicate that there has been a reduction of fitness in wild populations in the short term when wild and domesticated salmonids have interbreed.

   Overall Conclusion : After review of the available scientific information, the Committee finds no scientific basis to revise the protocols, and thus no change is recommended to protocol 2.2.1.

   Simply stated, the Scientific Review Committee does not support the amendments to the Policy on the Introductions and Transfers of Salmonids and further states that interaction between wild and farmed Atlantic salmon results in a reduction of fitness in the wild populations.

   At the root of the debate over amending the protocols on the introductions and transfers is the opportunity for the aquaculture industry to use non-native strains of Atlantic salmon which, they feel will make the industry more competitive.

6. If only North American derived AS broodstock are to be used in aquaculture in Atlantic Canada, is the origin of the domesticated broodstck a concern?
   Conclusion : In Atlantic Canada, there is no direct evidence to indicate that interbreeding between wild and escaped domestic salmon has directly lead to the reduced fitness of wild populations. No surveys have been conducted to evaluate this issue. However, relatively "local" domesticated strains have been used, and this would tend to reduce genetic differences between wild and domesticated populations. If more geographically distant North American domesticated strains are used in aquaculture and they escape and breed with wild fish, reduced fitness of wild populations would be expected, similar to observations in European populations.

   This statement tell us quite clearly that the experiences of European aquaculture must not be repeated here in Canada. There is evidence that we can expect negative impact in the event non-native farmed Atlantic salmon interbreed with wild stocks.

   The Scientific Review Committee also addressed the following questions and provided the following conclusions;

7. Is sterilization of cultured rainbow trout necessary to protect wild AS stocks
   Conclusion : Although available scientific information is sparse, it does indicate the potential interspecific competition between the two species with negative consequences to the native Atlantic salmon. In consideration of this and that rainbow trout are escaping from culture facilities in significant and increasing numbers, the Committee agrees that precautionary measures would be prudent.

   The Committee concluded that the risks would be minimized without sterilization as specified in the draft protocol, provided all cultured rainbows were rendered mono-sex and they were adequately contained. This latter measure is important because without such improvement the potential for direct interaction between escaped rainbow trout and Atlantic salmon will continue to exist.

   In regards to risk analysis, the Scientific Review Committee strongly supports the use of risk analysis in decision making relative to introductions and transfers of aquatic organisms.