Open ocean aquaculture, also known as offshore aquaculture, involves raising fish in large cages or pens in open waters. It is a hazardous system: the fish escape, the waste gets out, diseases in the pens spread to the surrounding sea life, and drugs used to treat the fish leak out into the environment.
Where Is It Happening?
Open ocean aquaculture is not currently allowed in U.S. federal waters (which begin several miles from the coast) but it is already happening in waters regulated by some states including Washington and Maine. However, federal regulators want to allow open aquaculture in order to reduce our "seafood trade deficit."
Here are some highlights from the fact sheet, which makes clear the drawbacks of open ocean aquaculture:
- In open ocean aquaculture, seawater flows freely through the pens, spreading waste, disease, antibiotics and chemicals used to treat the fish. This produces excessive nutrients that fuel the growth of algae which can greatly reduce oxygen levels in the water and lead to suffocation of sea life.
- Diseases such as parasitic sea lice and infectious salmon anemia can spread quickly through open aquaculture pens and infect wild salmon. In Norway, parasitic lice kill about 50,000 wild salmon every year and have reduced the regional wild salmon population to less than 500,000, as compared with 1 million in the 1980s.
- Fish frequently escape from open ocean aquaculture facilities, introducing non-native species into the environment and disrupting existing sea life.
- Open ocean aquaculture facilities eliminate fishing jobs by undercutting wild fish prices.
- The bulk of imported seafood is shrimp, so the growth of open ocean aquaculture will not lead to a decrease in imported seafood or solve the "seafood trade deficit."