Freedom To Roam and Oceans As Wilderness: Eye On Aquaculture
Today's post is by Patagonia Fly Fishing Ambassador, Topher Browne, who has dedicated his energies to the protection of salmon for two decades. Says Topher, "A species that requires not one but two entirely separate ecosystems would seem a dubious proposition. The transition from fresh water to salt water and back again . . . requires some fairly elaborate plumbing within the salmon or steelhead. This adaptation is unnecessary in species of fish that do not migrate to the sea. Activism on behalf of anadromous species is a real bang for the environmental buck. As salmon and steelhead lead a bipolar life, you can focus your efforts in both fresh and salt waters. If something is wrong at any stage of their life cycle, the fish will let you know." Today, Topher's letting us know a few things about Atlantic Salmon, and why it makes sense to choose wild:
They lie glistening on beds of frozen crystals in the great food halls of North America and Europe. Bland and lifeless eyes regard busy shoppers as they push their carts in front of polished displays. Their silver-scaled bodies—plump yet strangely devoid of muscle—advertise the healthful benefits of omega-3 fatty acids and the singular bounty of the sea. Atlantic salmon, the king of fish and the food of kings, is on sale for three dollars a pound.
Although reared in the ocean, these salmon live a life behind bars. They are raised in cages along the coasts of the United States, Canada, Chile, Scotland and Norway. They are genetically modified to accelerate their growth and liberally dosed with antibiotics and pesticides to mitigate the spread of rampant disease and parasites. They are fed a diet of ground-up fish containing chemical dyes to give their flesh a rosy hue. Some of their tribe escape through holes in their cages and enter rivers where they compete with wild salmon. It’s an old story—greed, disinformation, a willful disregard for the health of our most sensitive and bounteous ecosystems—and one that is unlikely to be told as the butcher hands you a carefully wrapped filet.
[A British Columbia Salmon Farm, photo courtesy of the BC Salmon Farmers Association. ]
Global production of farmed salmon has recorded exponential growth in the last 20 years. Salmon farming (aquaculture) is a thriving industry along the coasts of Maine (U.S.A.), New Brunswick and British Columbia (Canada), Scotland, Norway and Chile. Proponents of salmon farming maintain that the expansion of the industry relieves pressure on ocean fisheries while introducing a sustainable and healthy protein alternative to the general consumer. Unfortunately, these claims are not supported by the industry’s abysmal environmental record.Salmon farming requires large inputs of wild fish to feed farmed salmon in the cages. A farmed salmon requires 2.4 pounds of wild fish for every pound of body weight (Naylor et al., 1998). Large quantities of mackerel, herring, sardines and other forage fish—the fuel of the ocean food chain—are captured and ground up to provide a high-protein diet for farmed salmon. The conversion of wild forage fish into fish meal depletes these important species, which in turn impacts the survivability of those predators that rely on them – which includes wild salmon.
Pollution, both environmental and genetic, is an inevitable byproduct of salmon farming in oceans. Uneaten food and the feces of farmed salmon sink to the bottom of the cages where they generate oxygen-depleting bacteria that affect the health of shellfish and bottom-dwelling fish. Pesticides and antibiotics used to counteract the spread of parasites (sea lice) and infectious disease disperse with ocean currents and concentrate in estuarine sediments. Salmon farms are frequently located in areas with extreme tides (Bay of Fundy), which facilitates the dispersal of waste products and the spread of pesticides and antibiotics.
Sea cages, in theory, separate farmed salmon from wild salmon. The cages, however, are far from foolproof—and large-scale escapes of farmed salmon are common. These escapees comprise a substantial proportion of mature salmon on the spawning beds (>20%) on rivers located within 20 kilometers of salmon farms (Gausen et al., 1991). Fish-farm escapees are able to interbreed with wild salmon in the Atlantic Ocean, which severely compromises the genetic integrity of salmon that are optimized for survival in specific watersheds.
The aquaculture industry has been slow to acknowledge the effects of fish-farm escapes. Mainstream Scotland, part of the Norwegian salmon conglomerate CERMAQ, refused to accept the presence of juvenile farmed salmon in the River Devon, a tributary of the Forth, at a location that contains no population of wild salmon (Trout & Salmon, August, 2009). Mainstream Scotland accepted responsibility for the escape when confronted by Fish Legal, a non-profit organization that fights pollution and other damage to the aquatic environment throughout the United Kingdom. Mainstream Scotland agreed to an out-of-court settlement of £13,000 to cover the cost of removing the fish-farm escapees.
The Scottish Government reported an escape of 58,800 farm-raised salmon on September 14, 2009 at Strone Point, Argyll, Scotland due to a hole in a net. Each farm-raised salmon weighed an average of 700 grams (1.54 pounds). The total number of farm-raised salmon to escape from ocean pens in Scotland now stands at 131,964 salmon in 2009. A total of 58,641 escapees were reported in 2008. Intrafish, an on-line publication, has recorded 22 escapes and the loss of 288,581 farm-raised fish from pens located on the coast of Norway in 2009.
The epidemic of fish-farm escapes and disease transmission is not limited to the Atlantic Ocean. Marine Harvest Canada reported an escape of farm-raised salmon from its site in Port Elizabeth, British Columbia on October 21, 2009. Divers discovered holes in two pens at the site located within the Broughton Archipelago between Vancouver Island and mainland British Columbia. Marine Harvest Canada, a subsidiary of a Norwegian conglomerate, estimates that 40,000 farmed salmon with an average weight of 4.7 kilograms (10.36 pounds) escaped from the two pens. The Living Oceans Society reports that farmed salmon have been found in more than 80 river systems in British Columbia.
An outbreak of Infectious Salmon Anemia (I.S.A.) is killing millions of farmed salmon in Chile. An article in the New York Times (March 27, 2008) cites overcrowding as a likely culprit in the transmission of I.S.A. A report by the Ministry of Economy in July 2009 states that 325 tons of antibiotics were used in 2008 to stem the spread of the disease. Safeway and Walmart, two of the largest importers of farmed salmon, recently announced that they will no longer carry Chilean salmon due to concerns over the high use of antibiotics. The Times article states that certain antibiotics used to treat farmed salmon in Chile are illegal in the United States. The fitness of these antibiotics for human consumption is currently under investigation.
Sea-lice infestations, an unavoidable byproduct of the aquaculture industry, kill wild juvenile salmon as they migrate past sea cages in shared estuaries. Sea lice (Lepeophtheirus salmonis) occur naturally in salt water, consuming the blood, mucosa and flesh of wild and farmed salmon alike. Sea cages theoretically enclose a population of farmed salmon while removing the threat of large predators. Unfortunately, the cages also concentrate these industrial fish in unnatural densities, rendering them susceptible to sea-lice infestation. Sea lice also enhance the transmission of Infectious Salmon Anemia, a potentially fatal virus for both wild and farmed salmon.
Wild juvenile salmon leaving their natal rivers are particularly vulnerable to sea-lice infestation as they migrate past the cages. A concentration of 11 sea lice on a wild, 21-centimeter Atlantic salmon is lethal; a concentration of eight to 10 sea lice severely compromises its survival rate. Scientists have recorded as many as 104 sea lice per juvenile salmon on the west coast of Norway (Hoist et al., 2007). The sea cages present wild juvenile salmon with a potentially lethal barrier through which they must migrate in order to reach their ocean feeding grounds. The necessity for “freedom to roam” applies equally to natural corridors on land and in the ocean.
Certain species of Pacific salmon are even more vulnerable to sea-lice infestation. A single sea louse on a Chum or Pink salmon fry (juvenile salmon) can be fatal. An article in the peer-reviewed magazine Science (December 14, 2007) states that recurrent louse infestations of wild juvenile pink salmon associated with salmon farms in the Broughton Archipelago “have depressed wild pink salmon populations and placed them on a trajectory toward rapid local extinction.” Other species of Pacific salmon are similarly affected. Projected returns of sockeye salmon to the Fraser River near Vancouver, British Columbia in 2009 are less than one tenth of their usual abundance (Reuters August 13, 2009).
Our oceans are under siege. Pollution, ocean acidification and over-fishing pose serious threats to the breadbasket of a burgeoning world population. Salmon farming, once seen as a potential solution to reduced harvests of wild fish, is not a sustainable industry in current practice. Salmon farming must move to closed-containment systems on land in order to eliminate large-scale escapes of farmed salmon. Septic systems must process waste and the surfeit of antibiotics and pesticides generated by the industry. The presence of these chemicals in the treatment of farmed salmon also calls into question their essential fitness for human consumption. The science is in, governments are turning a deaf ear, and the clock is ticking.
[Above, left - Photo: Bill Klyn. Above, right - Photo of Atlantic Salmon by Paul Nicklen, Canada, for National Geographic Magazine. 1st place for UNESCO's World Press Freedom Day, 2004]