Effects of parasites from salmon farms on productivity of wild salmon

The ecological risks of salmon aquaculture have motivated changes to management and policy designed to protect wild salmon populations and habitats in several countries. In Canada, much attention has focused on outbreaks of parasitic copepods, sea lice (Lepeophtheirus salmonis), on farmed and wild s...

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Bibliographic Details
Published in:Proceedings of the National Academy of Sciences
Main Authors: Krkošek, Martin, Connors, Brendan M., Morton, Alexandra, Lewis, Mark A., Dill, Lawrence M., Hilborn, Ray
Format: Text
Language:English
Published: National Academy of Sciences 2011
Subjects:
Online Access:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3167527
http://www.ncbi.nlm.nih.gov/pubmed/21873246
https://doi.org/10.1073/pnas.1101845108
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Summary:The ecological risks of salmon aquaculture have motivated changes to management and policy designed to protect wild salmon populations and habitats in several countries. In Canada, much attention has focused on outbreaks of parasitic copepods, sea lice (Lepeophtheirus salmonis), on farmed and wild salmon in the Broughton Archipelago, British Columbia. Several recent studies have reached contradictory conclusions on whether the spread of lice from salmon farms affects the productivity of sympatric wild salmon populations. We analyzed recently available sea lice data on farms and spawner–recruit data for pink (Oncorhynchus gorbuscha) and coho (Oncorhynchus kisutch) salmon populations in the Broughton Archipelago and nearby regions where farms are not present. Our results show that sea lice abundance on farms is negatively associated with productivity of both pink and coho salmon in the Broughton Archipelago. These results reconcile the contradictory findings of previous studies and suggest that management and policy measures designed to protect wild salmon from sea lice should yield conservation and fishery benefits.