Salt content in herring – How the salt content in herring changes during capture and catch handling

Summary

Brazil applies a threshold limit value for the amount of salt that is accepted in natural herring, namely 134 mg sodium per 100 g fillet. Compared with the salt content values found in the relevant literature, and the measurements that are routinely performed in Norway, this is a low value that would be difficult to fulfil. RSW (Refrigerated Sea Water) is a quick and appropriate agent for chilling large catches – of herring, for example. However, when fish are stored in RSW after capture, they may assimilate salt from the cooling medium. Another factor that can increase the salt content in herring is stress. When herring are subjected to stress, as happens during capture, the salt content in their blood will increase. All in all, the threshold limit value set for salt content in Brazil is considered to be unrealistically low, taking into account how catches are handled in Norwegian pelagic fisheries. * The original report is in Norwegian and the reference is: 8/2023, ISBN 978-82-8296-743-3