Fish Facts
What problems are associated with fish farms?
There are several problems associated with current fish farming practices:
Sewage from farms pollutes surrounding waters. "Nutrient loading from aquaculture can be significant on a local scale. A salmon farm of 200,000 fish releases an amount of nitrogen, phosphorus, and fecal matter roughly equivalent to the nutrient waste in the untreated sewage from 20,000, 25,000, and 65,000 people, respectively" Goldburg, R. et al. (2001). Marine aquaculture in the United States: Environmental Impacts and Policy Options. Pew Ocean Commission, p. 13.
Drugs, including antibiotics, are required to keep farmed fish healthy. "In Norway the most serious disease effects to date have been the introductions to wild populations of lethal parasites and diseases from cultured fish. In recent years more than 30 (now 41 - ed.) of Norway's 500 salmon populations have become so infected by the parasite Gyrodactylus salaries that they have had to be completely destroyed…Efforts by Norwegian authorities to prevent the further spread of the parasite to rivers and hatcheries have involved a rotenone treatment program (total poisoning of rivers to kill all fish, infected as well as uninfected)."David Ellis and Associates (1996). Net Loss: The Salmon Netcage Industry in British Columbia. David Suzuki Foundation, p.179-181. "The use of antibiotics, however, is arguably a health risk for people and farmed fish, since it promotes the spread of antibiotic-resistance in both human and fish pathogens. At least a few types of bacteria associated with fish, such as Streptococcus, can be pathogenic to humans (Weinstein et al., 1997). If strains of these bacteria develop higher levels of resistance to antibiotics, infections by these bacteria may be difficult to treat. More generally, resistance can potentially spread to other types of bacteria, including human pathogens, through gene transfer mechanisms special to bacteria (Dixon, 2000).... A U.S. Center for Disease Control and Prevention (CDC) literature review indicates that certain antibiotic resistance genes in Salmonella-bacteria that can cause severe food poisoning in people-might have emerged following antibiotic use in Asian aquaculture (Angulo, 1999)." --Goldburg, R. et al. (2001). Marine aquaculture in the United States: Environmental Impacts and Policy Options. Pew Ocean Commission, p. 16-17.Escapes of farmed fish (alien species) threatens native wild fish.
Farmed fish are fed pellets made from other fish - depleting other fish species on a global scale. Net loss of Protein in 1999: 2,126,000 tons of fish taken from the oceans to produce 871,200 tons of farmed salmon.
http://www.breastcancer.org/research_farm_raised_salmon.html http://www.cnn.com/2004/HEALTH/01/08/salmon.pollution.ap/ http://www.davidsuzuki.org/Oceans/Aquaculture/Salmon/ www.sectionz.info/Issue_1/Facts_Footnotes.html
Do farm-raised salmon contain more toxins than wild salmon?
According to a study funded by the Pew Charitable Trusts published last year in Science magazine, yes, farm-raised salmon contain “significantly higher” levels of toxins than wild salmon. Researchers collected and analyzed over 700 salmon samples from various seafood wholesalers and retailers in many different parts of the world. The chemicals they looked for were PCB (polychlorinated biphenyl), dioxin, toxaphene, and dieldrin. All of these are suspected to cause cancer in people. Then, based on the EPA health guidelines, the researchers figured out how much salmon they considered safe to eat, given the toxin amounts found in the fish.
Why do farm-raised salmon contain so many toxins?
The problem is that farm-raised fish are fed pellets of concentrated fish products, which naturally contain toxins from the environment. These pellets are made by drying and grinding up fish that are picked up in fishing nets, but are not the types regularly consumed by people. Fish bones, skin, and guts are all part of the mix. The resulting pellets include not just the fish parts, but whatever toxins (harmful chemicals) have built up in the fish's body over their lifespan. Some of these toxins come from environmental pollutants and are stored in the fatty part of the fish, right under the skin. When farm-raised fish are given the concentrated fish pellets, they take in concentrated chemical toxins. When wild "free range" salmon eat the fish that are in their environment, they take in regular levels of toxins (not concentrated). For example, one meal of pellets may contain the dried and compressed body parts and toxins from several whole fish, but the same amount of food for a wild salmon would consist of just a few bites of one fish.
Are farm-raised salmon nutritionally different than wild salmon?
It is widely accepted by doctors that single serving of most seafood, including wild or farmed salmon, provides the daily requirement of healthy Omega 3 - an essential fatty acid with many health benefits. However, wild fish have a higher Omega 3 to Omega 6 ratio than farmed salmon. Farmed Atlantic salmon also contain higher levels of unhealthy saturated fats than wild Coho, Sockeye, Steelhead, Pink and Chum salmon. In addition, research indicates farmed salmon have up to 10 times more PCBs and dioxins than wild salmon. According to a comprehensive study published in the respected journal Science, in most cases, consuming more than one serving of farmed salmon per month could pose unacceptable cancer risks.
How many times a month should I eat salmon for optimum health?
After comparing toxin amounts with EPA health guidelines, researchers recommend that people eat farmed salmon no more than once a month to avoid risk from the cancer-causing toxins they contain. It is safe to eat as many as eight meals of wild salmon a month. "We are certainly not telling people not to eat fish. ... We're telling them to eat less farmed salmon," said one researcher in the famous study, David Carpenter of the University at Albany, New York.
What do I need to know about Mercury in fish?
Nearly all fish contain some levels of mercury. However, longer-lived fish and fish that feed on other fish contain higher levels of mercury. Pregnant women, women who are nursing, or young children should not consume fish such as Shark, Swordfish, King mackerel and Tilefish. Please visit www.cfsan.fda.gov/~dms/admehg.html or extoxnet.orst.edu/faqs/foodcon/mercury.htm for more information or click here.
What commercial fish species are naturally abundant and which are falling to unsustainable numbers?
Although local harvest numbers may vary from year to year, a good source for commercial seafood can be found at http://www.mbayaq.org/cr/seafoodwatch.asp where you can print out a card to keep in your wallet for trips to the grocery store. Bear in mind that some species listed in the website are farmed, and as mentioned above, farmed fish may have some detrimental effects on ocean and human health
