Color fan used to pick the desired flesh color of salmon using artificial colored pellets.
Sustainable Seafood
Farmed and genetically-engineered fish
Farmed fish
Nearly 20 percent of the world's seafood comes from farms. That can be good or bad depending on the species, and how and where it's raised.
Sustainable seafood lists steer customers toward farm-raised shellfish such as oysters, clams and mussels. These shellfish are filter feeders, eating plankton from the water, and so do not require wild fish for feed. In fact, these species can improve water quality. Farming shellfish in nets, trays, or racks suspended in the water is an ocean-friendly alternative to dredging.
Public opinion poll
A poll from the American Association for the Advancement of Science found that 60 percent of Americans would eat less of some fish to help protect the environment.
Research by the Seafood Choices Alliance in 2001 also found 67 percent of Americans are interested in getting more information about what seafood is over-fished or caught in a way that's harmful to other marine life.
Salmon is another story. Wild salmon from California or Alaska is the best choice, but farmed salmon is on the "avoid" list. Dense living conditions in net pens along coastal waters lead to disease, requiring use of antibiotics in fish feed. Steroids, chemical dips, vaccinations and added coloring also are widely used in farmed salmon. Hundreds of thousands of farmed Atlantic salmon have escaped, competing with wild salmon and diluting native genetic stocks.
Aquaculture usually does not ease pressure on declining wild populations. Often, it does the opposite. Most fish need to eat other fish so catching wild fish to turn into pellet feed for farmed fish means there are fewer in the wild to serve as prey for the wild ones that are left. It takes an estimated two to five pounds of fish to raise one pound of farmed brown shrimp. Most of the world's shrimp are farmed in Southeast Asia where coastal wetlands and mangrove forests have been destroyed to make room for shrimp farms. These coastal wetlands and mangroves were a natural nursery for many varieties of marine life.
Water pollution from dense living conditions in coastal fish farms can severely impact traditional coastal economies. Aquaculture requires sizeable investment, land ownership and large amounts of clean water, which most coastal people around the world do not have. Aquaculture as carried out by many nations produces shrimp and expensive types of fish only for export to wealthier nations, leaving most of the local people to struggle for their own needs in a degraded environment.
Some fish farms are more environmentally friendly than others. The National Audubon Society, Natural Resources Defense Council and other environmental experts say it's possible to farm fish and do less damage with "closed systems" built inland. The waste from closed systems is easier to process and closed systems can better control pollution and escapes.
"Open systems" with ponds or nets containing the fish in wetlands or at river mouths are more problematic than closed systems in general. Some Atlantic salmon farmers in Maine use "open systems" and rotate their fish-raising pens to give these areas time to recover. This is proving effective in reducing disease and pollution, which led numerous environmental groups to give this Atlantic salmon a "green" rating for sustainability, although other Atlantic salmon is in the "red" zone.
Genetically engineered fish
Farmed fish that are genetically engineered further threaten the genetic strength and diversity of fish. A 2004 study from the National Academy of Sciences shows that genetically engineered (GE) salmon not only will eat all the food needed by other species in the wild, but also will virtually annihilate each other.
The researchers compared activity between GE salmon and normal salmon in closed tanks with the level of food varying. When there was plenty of food, the normal and GE salmon coexisted well. When food became scarce, the competition turned deadly and the GE salmon began attacking and eating the other salmon. At the end of the study, only one or two GE fish were left in tanks that originally had 50 fish.
This is increasing concern for what could happen if GE salmon are approved for commercial production and begin escaping their pens, as other farmed fish have. GE salmon are engineered to grow twice as fast as normal salmon during the early stages of their life, but at maturity are about the same size. It seems that in the process, their drive for food and aggressiveness also increases. GE fish have not been approved for the retail market.
