Results of new research will make it easier to distinguish farmed salmon that has escaped from the natural wild salmon.
The visible markings will reduce the problems that are currently associated with escaped farmed salmon. Research spearheaded by the food research institute Nofima states that the cheapest and most efficient way of marking the salmon would be through removal of the adipose fin.
During the research period, the fish was marked under anesthesia and there was no indication that the fish experienced any negative reaction. “There is reason to believe that this is no different to the tagging of animals, which has been common for a long time,” says
Senior Scientist Atle Mortensen at Nofima. “With partial removal of the adipose fin, we observed partial regeneration in half of the marked fish, but with complete removal of the adipose fin regeneration was not a problem and the marking was clearly visible for the duration of the trial,” says Mortensen.
However, marking all the 200 million salmon that are transferred to sea cages every year in Norway would be a formidable job, and all marking would have to be performed in accordance with the Animal Welfare Act. “An overall assessment shows that the durability/readability, effect on growth and survival, technology and any market reactions indicate that complete removal of the adipose fin is the only one of the tested methods that can be recommended,” concludes Senior Scientist Atle Mortensen.
Source: The Fish Site