Annual report on health monitoring of wild anadromous salmonids in Norway 2018 - Screening of migrating Atlantic salmon (Salmo salar) postsmolts from the Trondheim fjord for viral infections

Abstract

Very few virus infections found in migrating postsmolts from the Trondheim Fjord Commissioned by the Norwegian Food Safety Authority, the Institute of Marine Research has studied the occurrence of several potential disease-causing viruses that are common in salmon farming in imigrating postsmolts from Trondheim fjord in 2016. The postsmolts were caught in the mouth of the fjord, which is a national salmon fjord without fish farming activity, and therefore it is unlikely that this fish is exposed to infections from salmon farming. The incidence of SAV, PRV1, ILAV and PMCV infections was tested using the real-time RT-PCR method. SAV, PRV1, ILAV were not detected in any of the postsmolts. Low concentration of PMCV was detected in a single fish. The results show that the occurrence of these viruses is very low in wild salmon postsmolts in this area of the fjord.