The David Suzuki Foundation web site has released (March 29, 2005) a report entitled: “Fish farm causes sea lice abundances thousands of times higher than natural levels, new study confirms”
The results show transmission of lice from farmed salmon to migrating wild salmon peaked at an intensity of 70 times greater than natural near the farm and continued to exceed natural levels for 30km along the migration route. This amounts to a total contribution of lice from the farm that was 30,000 times higher than natural.
There are documents outlining the research methods and results available for download from the above link.
The Foundation has begun examining sustainable aquaculture practices and has found, in the British Columbia region of Canada, aquacultural practices are “polluting the environment and seriously threatening the integrity of wild stocks”.