Estimating the temporal overlap between post-smolt migration of Atlantic salmon and salmon lice infestation pressure from fish farms

Kw Vollset,Ot Skilbrei,S Mahlum,Bt Barlaup,Pa Bjørn

doi:10.3354/aei00195

Abstract

Estimating the temporal overlap between post-smolt migration of Atlantic salmon and salmon lice infestation pressure from fish farms

Highlights

The initial post-smolt migration of salmon from the river to the ocean is generally a period of high mortality (Lacroix et al 2005, Thorstad et al 2007, 2011a,b, 2012b, Lacroix 2008, Dempson et al 2011)
Farmed fish in net pens can function as source populations for diseases and parasites such as sea lice that can be transferred to wild fish
We found that the progression rate of cultivated Atlantic salmon post-smolts, calculated by the mark−recapture method using CWT tags and trap nets, is a function of fish length, condition factor, river discharge and fish origin

Summary

Introduction

The initial post-smolt migration of salmon from the river to the ocean is generally a period of high mortality (Lacroix et al 2005, Thorstad et al 2007, 2011a,b, 2012b, Lacroix 2008, Dempson et al 2011). This mortality partially results from a combination of the vulnerability of salmon smolts during the physiologically challenging transition from freshwater to saltwater habitat (Strand & Finstad 2007, Strand et al 2011) and the aggregation of predators in near-shore habitats (Hvidsten & Lund 1988, Handeland et al 1996). Understanding the timing and duration of smolt migrations through areas of high concentrations of fish farms is essential to be able to optimize and evaluate the effect of such mitigation efforts

Methods

Results

Discussion

Conclusion