Fish Farms Drive Wild Salmon Toward Local Extinction

Published by: David Suzuki Foundation
Authored by: Marjorie Wonham, Martin Krkosek

Biodiversity, Oceans and fresh water, Cities species at risk, fisheries and aquaculture, British Columbia, salmon, conservation, water systems

This is the summary of the report Declining Wild Salmon Populations in relation to Parasites from Farm Salmon, which was conducted by a team of biologists, fisheries scientists and mathematicians from Dalhousie University and the University of Alberta and published in the peer-reviewed journal Science in December 2007. It investigates the impacts of sea lice from fish farms on wild salmon abundance. The results, from empirical data analysis and mathematical modelling, show that recurrent sea-lice outbreaks cause 33 per cent to over 99 per cent annual mortality of pink salmon on the central British Columbia coast. Under current conditions, the population is expected to decline to regional extinction, with 99 per cent loss predicted in the next four salmon generations (eight years).