Properly sited salmon farms have minimal and reversible impacts on the sea floor.

Salmon aquaculture, like any other form of large-scale food production, has the potential to impact the local environment.  The impacts of marine farms on the sea floor, from salmon faeces and any excess fish feed, are confined primarily to the ocean floor in the immediate vicinity of salmon farms.  These impacts are generally short-term, and reversible. Salmon waste and uneaten feed on the ocean floor can cause temporary oxygen reduction and other chemical changes as they decompose, and may cause an increase in the concentration of metals such as copper or zinc.  For this reason, salmon farms are situated in deep waters with sufficient current to disperse organic wastes.  In addition, farm sites are fallowed (emptied of fish) periodically to allow natural rejuvenation of the sea floor.  For more information, see the Benthic Impact Study by Kenneth Brooks (2001) or go to to Minimizing Benthic Impacts.