The Effects of Fisheries

Increased Stocks

• Fish farms help supply a growing demand for fish. According to the World Health Organization, demand for fish grew significantly in the 1950s, 1960s and leveled off in the 1970s, which suggests that fish as a resource had reached a maximum rate of exploitation. Fish farms, on the other hand, have been steadily producing more fish, and have made up for the increased demand on fish stocks. With enough production, wild stocks might even have a chance to recover.

Sea Lice

• Fish farms force an unnaturally large number of salmon to cluster together, creating ideal breeding conditions for sea lice, which is a parasite often deadly to juvenile salmon. Sea lice are an accepted part of doing business with farmed salmon, but the problem is that many fish farms are near to the mouths of rivers, and passing wild salmon are then at increased risk of becoming infected and dying as a result.

Genetic Alterations

• Fisheries also create a risk of farm salmon undergoing genetic alterations. Much like other animals farmed for consumption, salmon are genetically altered to increase their adult size. These genetic alterations, however, have other effects as well. Biologist Rick Howard of Purdue University has studied how genetically modified fish have a breeding advantage over wild fish because of their larger size. The research also demonstrated that these genetic alterations cause offspring to be less likely to survive to adulthood, which has an overall negative affect on the population of wild salmon.

Habitat Destruction

• Finally, fish farms also have a significant effect on the surrounding marine environment. The large concentrations of fish in one area produces huge amounts of feces, for example, which is laced with the various drugs that are fed to the fish. Bacterial contamination can set in as a result and result in significant changes to the marine ecosystem of the area. Fish farms can move, but the marine ecosystem might be very slow to recover.