Net pen farms provide environmental benefits
The study, prepared for the National Fisheries Service, the National Sea Grant Program and the National Oceanic and Atmospheric Administration, was carried out in the Puget Sound in Washington State. The report found many species of invertebrates and seaweeds that could be considered important prey items, according to an article in Northern Aquaculture.
Contrary to popular misconceptions and media reports that fish farms create a biological wasteland, this report describes wild species of plants and fish that amounted to some 55 tonnes from just one farm. The report suggests that the so-called "biofouling" of anchor lines, floats and other farm structures can certainly be considered a beneficial effect of fish farming. It adds that no harmful or invasive species were found.
The report also describes salmon farms in the U.S. as "rarely using antibiotics due to the availability of vaccines, and sea lice is not an issue due to relatively low salinity levels. Waste build-up is also avoided due to deep water with good currents, which distribute the waste over a large area so it can be incorporated in the food web while maintaining aerobic conditions on the bottom".
