Photo credit: ©Dyrevernalliansen
Suspiciously high mortality levels of Norwegian juvenile salmon were found in the report produced by Dyrevernalliansen and the Norwegian Veterinary Institute earlier this month. Since Norway is the world’s biggest producer of Atlantic salmon this finding sheds an important light on the lack of appropriate welfare measures for Norway’s largest, yet most vulnerable livestock group – salmon hatcheries.
Part of the larger project named Småfiskvel (Smallfishwell), the research aimed to compare mortality rates with operating conditions in hatcheries and identify particular success factors in the maintenance of welfare standards. Some of the topics covered were production form, bio safety, water quality and causes of mortality. The highest mortality rates were found in the juveniles in the life stage when fish are moved from a protected environment that allows them to hide in “astroturf” to open tanks with constant light exposure. The high mortality rate may indicate that the transition is a major challenge for the small fish weighing less than 3 grams.
The data revealed consistent mortality rate differences among production sites as well as constantly high mortality rates over several years in some sites, indicating that the cause can’t be rooted in biology but in production methods and routines. In addition, the unexpectedly poor level of reporting was found among producers. From this it is clear that the lack of consistent and detailed reporting leads to critical welfare challenges. Moving forward, Dyrevernalliansen is committed to introduce daily or weekly reports that will allow for better monitoring and welfare improvements throughout the production process.