Is the Increased Production of Farmed Fish Environmentally Sustainable?

These days, a lot of the fish we buy in the supermarket comes from fish farms. As wild fish stocks dwindle and fishing fleets disappear, more and more fish is farmed all over the world: shrimp in Thailand, salmon in Chile, the U.S., and Norway, tilapia from Central America and China, just to name a few popular fish counter varieties. As seafood watch groups alert the public, not all farmed fish is created equal, and just as not all wild caught fish is considered to be environmentally sustainable, farmed fish can wreak havoc on the environment and is not necessarily a very sustainable food source.

The environmental impacts of eating fish, both farmed and wild are enough to make me extremely wary of buying fish unless I know precisely where it came from, how it was caught, etc. But the fact that fish that comes from farms is projected to make up a whole half of the fish produced and harvested in the world two years from now, in 2012, gives cause for extra caution. Increased fish consumption worldwide has meant increased pressure on the industry to produce more fish to meet the market demand. The fact that more and more fish is raised on fish farms is a direct result of the increased market demand. But how environmentally sustainable is it?

First of all, the fact that we need to produce fish on farms is a major warning sign. The fact that we are now relying so much on fish farms for food and fish products (like fish meal) means that we have completely exhausted most of our natural fish stocks. Clearly, though there are exceptions, we have not been successful in terms of creating systems of management that ensure a sustainable fish resource, and have therefore had to turn to farming our fish. There are many different ways to farm fish, depending on species, and location, among other variables. But all of the various methods come with pros and cons, some more than others, and especially if poorly managed. Some of the most common environmental hazards that develop with aquaculture are escaped fish that may not be native to the farming area or may carry disease, and farm effluent that results in toxic algae blooms and oxygen depletion. Many fish farms also use pesticides and herbicides that can leak into the surrounding environment, as well as antibiotics to keep their fish disease-free. Depending on the species, the farmed fish's diet demands increased fishing pressure on certain wild stocks, such as herring or sardines which are turned into fish meal for feed.

While farming our fish may take some pressure off wild fish stocks, the environmental impact of irresponsible aquaculture can be just as damaging and environmentally unsustainable as irresponsible fishing methods. But that doesn't necessarily have to be the case. While we should buy our fish wisely at the supermarket, we should also be demanding better regulations for aquaculture to make sure that the farms our fish come from employ the proper methods and technology to make the operation environmentally sound and sustainable. As the international appetite for fish continues to grow, we need to make sure that we're seeking out the best possible ways to farm fish, as well as doing all we can to help our natural fish stocks recover after years of overfishing.