  Fish farming? Yes, fish can be raised like other domesticated creatures, for human consumption. This practice has only recently become a profitable large-scale industry. The practice of farming fish in water is also called aquaculture.  The first recorded instance of fish farming actually dates back thousands of years to China, where freshwater carp were raised in ponds. Much later in Europe, catfish, sole, cod and sturgeon were raised in tanks or ponds. These operations were small, and usually environmentally friendly, in that wastes from the fish ponds were often used as fertilizer.
In the world today, where stocks of food-producing ocean life are often declining, many types of marine creatures are farmed instead. These include various types of fishes, primarily carp and salmon, as well as shrimp, clams and oysters. Today people around the world are eating more seafood than ever before, which makes the farming of marine life economically viable. In fact, aquaculture as an industry is growing every year, and is the fastest growing sector of the world food economy. Fish farming produces as much food worldwide as does cattle farming! However, the ecological impact of marine farming is often negative, sometimes disastrously so. More about that later. Fish farming makes sense. Cattle require about 7 kilograms of grain for every 1 kilogram of weight added, whereas fish can add a kilogram of weight with less than 2 kilograms of grain. In addition, it takes about 1000 tonnes of water to produce 1 tonne of grain for feed. Given our growing land and fresh water scarcity, the advantage of aquaculture over feedlots in the production of cheap animal protein is obvious. Currently, meat production (cattle, sheep) occurs primarily in the developed world, while most of the aquaculture takes place in developing countries such as China, India, Bangladesh and Indonesia. Industrialized countries that are beginning to explore aquaculture as a food source include the United States, Canada, Norway and Japan. In China, fish farming takes place in ponds, lakes, reservoirs and rice paddies. About 5 million hectares of land are devoted exclusively to fish farming, much of it various varieties of carp. In China, aquaculture is often combined with agriculture ... farmers use wastes like pig manure to fertilize fish ponds, stimulating the growth of plankton, which the fish eat. Fish farming seems to be environmentally friendly. In contrast, developed countries raise salmon in large metal or net cages in the ocean. Waste from the fish and chemicals added to the feed are allowed to flow freely out of the enclosures into the ocean. Some segments of the aquaculture industry have unresolved problems:
 In January 2004, the Journal Science warned that farmed salmon should be eaten only infrequently – once every month or two – due to the risk of cancer due to the food fed to the salmon, which is said to contain 10 times the contaminants, including pesticides and PCB's, found in the diet of wild salmon. (Federal officials in Canada and the U.S. contend that these dangers have been "overstated"). In fact, many foods have PCBs, but farmed salmon may have two to five times the PCB levels of beef, pork, milk and eggs. Clearly aquaculture, including fish farming, is an industry that can go a long way to helping solve the world's food scarcity. But what can be done to solve the pollution problems that affect the fish themselves as well as the surrounding waters? |