Salmon Louse Infestation Impairs the Long‐Term Survival of Sea‐Run Brown Trout
Knut Wiik Vollset, Bjørnar Skår, Robert J. Lennox, Rosa Maria Serra‐Llinares, Gunnar Bekke Lehmann

TL;DR
Salmon lice infestations significantly reduce the survival of sea-run brown trout, highlighting the need for better parasite management in coastal areas affected by aquaculture.
Contribution
This study provides the first field evidence linking parasite load to individual survival probability in wild sea-run brown trout.
Findings
A 73% reduction in survival probability per louse per gram of fish weight in 2020.
A 58% reduction in survival probability per louse per gram of fish weight in 2021.
Strong evidence of long-term ecological impacts of salmon lice on brown trout populations.
Abstract
Anadromous salmonids, including sea‐run brown trout, are exposed to ectoparasitic salmon lice during their sea migrations. The development of intensive aquaculture in coastal areas has promoted louse epidemics by substantially increasing the number of hosts available to the parasite. We employed a mark‐recapture study involving large‐scale traps to capture and PIT‐tag 676 wild sea‐trout during their early marine migration in spring 2020 and 2021. Each trout was examined for lice, tagged with passive integrated transponders (PIT), and monitored for subsequent survival using a PIT antenna system installed at the river Yndesdalsvassdraget. Using a Cormack‐Jolly‐Seber capture recapture model of individual re‐detections the subsequent years, we found a significant negative correlation between lice per gram of fish weight and the survival probability. Increasing lice load from 0 to 1 louse…
Genes, proteins, chemicals, diseases, species, mutations and cell lines named across the full text — each resolved to its canonical identifier and authoritative record.
Click any figure to enlarge with its caption.
Figure 1
Figure 2
Figure 3
Figure 4Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
Taxonomy
TopicsFish Ecology and Management Studies · Fish Biology and Ecology Studies · Aquaculture disease management and microbiota
