Spotting the difference between an escaped farmed salmon and a wild salmon is not always easy. But physical marking, such as clipping the adipose fin, freeze branding or colour marking of all farmed salmon, will show whether a salmon has escaped or not, without using time and money on DNA testing.
“The aim is that we can quickly and with a high level of certainty trace escaped farmed salmon back to their owner or the company responsible,” says Matt Baranski, Scientist at the food research institute Nofima.
In order to go to the fish farm where the farmed salmon is from, we need to make a detour via the genes of the salmon’s parents.
Following the gene trail
By using DNA markers, the scientists want to record the genotypes of the parents of all farmed salmon.
The parents of the farmed salmon may be found at the breeding company’s roe producers, where a male salmon is crossed with one or more female salmon. The offspring of each specific set of parents has a unique DNA profile, and by sending all fertilised eggs from one set of parents or parental group to a smolt producer along with a certificate of traceability, all fish from each smolt producer can receive a unique DNA profile. This will follow the fish when it is later transferred to a sea cage. The DNA profile will be stored in a national database so that the fish in the cage do not need to be tested in the event of suspicion of escaping.
If an escaped fish is captured, genotyping should reveal the correct parental match and therefore the responsible company.
The scientists will develop and test these methods on a pilot scale for a two-year period to ascertain whether it is feasible.
The industry’s initiative
They will also undertake a thorough analysis to determine how much implementing such a traceability system for the entire aquaculture industry will cost. The research is being funded by the Fishery and Aquaculture Industry Research Fund (FHF).
Is the aquaculture industry also willing to pay for a system in which it may be identified as the origin of the escape?
“Through the so-called Environmental initiative, the Norwegian Seafood Federation (FHL) wishes in 2012 to establish a system to trace any escaped fish back to the company it escaped from,” says R & D Director, Aquaculture at FHF, Kjell Maroni.
“This is an extremely ambitious goal, and FHF wished through the announcement of research on marking and tracing to strengthen the knowledge base in order to make the best possible choice of methods. Six projects are now being started that will make a major contribution of knowledge, and contribute in all likelihood to a step-by-step development.”
If everything goes as Maroni wishes, in 2014 we will have a cost-efficient, reliable and rapid method to find the origin of escaped farmed salmon.
Scientists from Nofima are leading one of the projects using DNA markers as a tracing tool, in collaboration with the Norwegian Institute for Nature Research (NINA) and research institutions in Australia and the Netherlands. The project is coordinated towards a similar project at the Norwegian School of Veterinary Science.