Ecological Fish Farms

A new type of aquaculture produces healthier salmon without polluting the ocean, by raising them on the land rather than in the sea. Only 20% of worldwide salmon production is caught in the wild. Most of the rest are farmed in open net cages off the coasts of Norway, Chile, the UK and other cold water locations. These farms are generally not clean, so they have to give the salmon mass quantities of antibiotics to keep them alive. In addition, they cause pollution in the surrounding water, and the fish they produce are not as healthy or nutritious as salmon in the wild. 
To remedy these shortcomings, new companies like Danish Salmon raise their fish on land in a closed water network. The seawater is cleaned through a biological purification system every 40 minutes. This eliminates the need for antibiotics. The water that is returned to the ocean has 80% of the phosphorus and nitrogen removed before pumping it back into the sea. These are the two substances that cause oceanic dead zones, and are produced in abundance by standard fish farms. The demand for salmon from land-based farms is growing rapidly, as consumers are willing to pay more for fish that is clean, healthy and sustainable.