Ireland: Researchers develop new health test for salmon smolt

The test can provide information that fish farmers will benefit from when transferring salmon smolt from freshwater to the sea. The results can help increase the smolts’ chances of survival. Every year, approximately 15 percent of farmed salmon die after being transferred from land-based freshwater tanks to net-pens at sea. Most of these fish die shortly after being transferred – making the test highly relevant for the industry. Nofima has developed a diagnostic test that measures the activity of 44 genes that regulate the immune system. A sample is taken from the gills or the dorsal fin without harming the fish. “A few years ago, we found that the immune system was weakened during smoltification. As a result, we decided to develop a test to measure the immune status of salmon during smoltification,” says Aleksei Krasnov, senior scientist at Nofima. To do that, Krasnov and his colleagues evaluated multiple genes and selected those that provided the most information about immune ...