New article on escaped farmed salmon highlighted in Nature
Analyses of recaptures of escaped farmed salmon reveal that much more salmon escape than is reported. This result was also noted in the Research Highlights of Nature!
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Years of experimental releases of farmed Atlantic salmon, lead by Dr. Ove Skilbrei from the Institute of Marine Research, have allowed estimation of their recapture rates under various conditions. Combined with data on numbers of recaptured escaped salmon in the whole country, it is possible to estimate how many salmon escaped in the first place. The estimate obtained this way is much higher than the officially reported number (farmers are under an obligation to report all escapes). There is uncertainty in the actual estimates, but the analyses suggest that the actual numbers of escaped salmon may be as much as three times the official numbers. The study has now been published in the ICES Journal of Marine Science. This important result was also picked up by the Nature Research Highlights!
References:
- Skilbrei, O. T., M. Heino, and T. Svåsand. 2014. Using simulated escape events to assess the annual numbers and destinies of escaped farmed Atlantic salmon of different life stages from farms sites in Norway. ICES Journal of Marine Science. doi: 10.1093/icesjms/fsu133.
- Farmed salmon swim to freedom. 2014. Nature 512:234. doi: 10.1038/512234a.
Annual production of farmed Atlantic salmon in Norway exceeds one million tonnes. A small fraction of farmed fish manage to escape because of accidents and mistakes. Escapes are always unwanted: they represent financial losses for the farmers, and they also constitute a threat to the genetic integrity of wild salmon populations.
