12/05/2005 - The ongoing debate between scientists and public health experts over the health impacts of eating farm raised salmon is not only confusing to consumers, but has regrettably overshadowed some of the other significant problems associated with farming fish in the sea. This is particularly worrisome now that the Bush Administration has proposed opening up America’s exclusive economic zone, the area that extends from 3 to 200 nautical miles from land, to aquaculture.Marine aquaculture, which is primarily confined to state waters, or that area within 3 miles from the shoreline, involves the production of mollusks such as oysters, clams and mussels, as well as fish. Fresh water fish such as carp have been farmed in ponds for thousands of years with little environmental damage. However, the raising of fish in the ocean is a relatively recent phenomenon, dating back to the early 1960’s. Most of the problems associated with marine aquaculture are linked to the farming of fish such as salmon which, because they are carnivores, are fed a diet comprised principally of ground up fish and fish oil.
There are numerous problems associated with raising carnivorous fish in densely packed net pens in the ocean. They include pollution and degraded water quality resulting from uneaten food and the large amounts of fecal material they produce, along with the pesticides, antibiotics, and other chemicals used to promote their growth, combat disease and control algae. When caged fish escape, as they do in large numbers each year as a result of storms or faulty infrastructure, they threaten wild fish populations by competing for available food and habitat, changing the genetic makeup of wild stocks through interbreeding, and spreading pathogens and parasites.
Perhaps the biggest problem, however, is that, on average, between two and three pounds of wild fish are needed to produce one pound of farmed fish such as salmon. Hence, while many people assume that farming marine fish serves to reduce pressure on wild fish populations, the opposite is actually the case. The farming of marine fish, the way it is practiced today, further exacerbates pressure on wild forage fish such as anchovies, herring and menhaden that are commonly used in fishmeal. In turn, this places additional stress on other parts of the marine food web that depend on these wild fish for food.
Government officials claim that raising fish and shellfish in the sea is similar to raising livestock on land. It is not. Beef and dairy cattle, sheep, and poultry are primarily herbivores. They eat little or no animal protein. A more apt land analogy to raising carnivorous fish would be rounding up wild deer and ducks to feed to farm-raised wolves or tigers. Obviously, we don’t do this as it would make no economic sense. It would cost far more to raise one of these meat eating animals than one could ever hope to gain from its sale as a food source.
The government also claims that a proposed $5 billion aquaculture industry, five times greater than that which currently exists, could generate 500,000 direct jobs. However, extrapolating from the marine aquaculture industry worldwide, the number of actual jobs likely to be created by an industry of this size is far lower, closer to 50,000.
Finally, the government argues that increasing the domestic marine aquaculture industry will help to offset the $8 billion annual trade deficit in seafood. One wonders, however, why taxpayers should subsidize a part of the seafood industry that has potentially damaging consequences to the U.S. marine environment, and also lowers prices that U.S. fishermen get for their catch, when the economic benefits are likely to be marginal at best.
While fish farming in the ocean may hold potential to produce seafood without damaging the marine environment, it does not now. Before further opening up the nation’s oceans to this type of activity, the aquaculture industry needs to fix some of the major environmental problems associated with raising carnivorous fish in the sea, and Congress should require that it do so. For unless steps are taken to ensure that farming marine fish is done with adequate environmental safeguards, the costs to the nation’s marine environment, and ultimately to all Americans, may far outweigh its benefits.
Joshua Reichert directs the Environment Program at The Pew Charitable Trusts. This op-ed column was also published by the Charleston Post and Courier, Houston Chronicle and Maine Sunday Telegram.