Like many things in life, fish farming is both less than you might think -- and more. It has some aspects that are relatively benign, and some that are truly disturbing.
Our goal today is to look at it objectively so you can decide how you want to incorporate it into your life, if at all. And by incorporate, I'm referring to both your diet and your political activism. Some of you may decide after reading this to take action against fish farms. If you do so, I would hope that you are selective in your activism as not all fish farming is the same, and the reality is that it's highly unlikely that you will be able to make it go away. It's now too entrenched in the world's economy…and diet.
Fish Farming History
Perhaps the biggest surprise for most people about fish farming is how long it's been around. One of the oldest accounts is a bas-relief that was found in a 4,000 year old Egyptian tomb showing Tilapia held in ponds. In ancient China, the oral narrative also goes back some 4,000 years, and the first written records still go back some 2500 years to 500 BC. 1 The Romans got into the act some 2,000 years ago when they first started cultivating oysters, and surprisingly, the methodology they employed is still unchanged today.2 The important thing to remember, though, is that fish farming is not a modern aberration. It's been around for thousands of years. Then again, it's also important to understand that all of the early forms of fish farming were different from modern practices in that they involved harvesting immature fish or
shellfish and transferring them to an artificially created environment favorable to their growth and designed for easy harvesting. That's it -- no high density farming, no artificial insemination, no manmade feeds, and no antibiotics.
That said, some of the key elements of modern fish farming still reach back to the mid 1700's when a German farmer, Stephen Ludvig Jacobi, successfully gathered fish eggs, fertilized them, and then grew and raised the fish that hatched. By the 1790's, Halesowen (Hales) Abbey had an elaborate fish pond system based on Jacobi's system, remnants of which are still visible today.3
Fish Farming Today
As the world's population grows, and as incomes increase in many third world countries, there is an increasing demand for non-vegetarian protein. And with land in scarce supply for raising farm animals, fish and fish protein provide an alternative. More than 3.5 billion people depend on the ocean for their primary source of food. In 20 years, this number could double to 7 billion. Unfortunately, this has led to widespread overfishing of many of the world's wild fisheries. Populations of commercially attractive large fish, such as tuna, cod, swordfish and marlin have declined by as much as 90 percent in the past century.4 Fish farming, then, provides an attractive option. Currently, some 70 to 75 million tons of fish are harvested each year from the ocean -- down from around 100 million metric tons in just the last six years. Of this amount, around 29 million tons is used for human consumption. Fish farming, on the other hand, now accounts for about 33 million tons, or about 45% of the wild caught total -- but slightly over half in terms of human consumption. This trend in favor of fish farming will only accelerate as oceans continue to deplete and the number of fish farms continues to grow. In dollars, fish farming now accounts for some $60 billion a year in revenues. It's very big business.
Essentially, fish farming involves raising fish commercially for food in ponds, tanks, or enclosures -- although some decorative fish such as koi are also raised on farms. Outside of shellfish, the primary fish farm species are salmon, carp, tilapia, European sea bass, catfish and cod. As a side note, the European sea bass was the first marine non-salmon species to be commercially cultured in Europe and at present is the most important commercial fish widely cultured in Mediterranean areas. Greece, Turkey, Italy, Spain, Croatia and Egypt are the biggest producers.
Major categories of fish aquaculture
Taken as whole, fish farming, depending on where you go, is both wildly different and remarkably similar. Ultimately, though, the idea is to improve the yield and costs over catching fish in the sea by, dare I say it, shooting them in a barrel. Given that similarity, the differences come down to nuance -- albeit important nuance. Factors that come into play include:
- What are you raising your fish in: ponds, cages, pens?
- Do fish stay their entire lives in one location, or are you releasing them into the wild after they've been "imprinted" to forage for food in a process known as "ranching" and await their return when they're much bigger and it's time to spawn?
- What do you feed your fish? Are they vegetarian or predators?
- Is your method of farming environmentally safe, or does it cause massive pollution?
- Does your farming method present any danger to your species' gene pool?
- Is it nutritionally comparable to wild caught versions of your fish?
- What kind of chemicals, antibiotics, and toxins end up in your fish VS what the fish might be exposed to in the wild?
- Is your farming operation inherently cruel -- and does that matter when we're talking about fish?
We don't have time to address all of these questions in detail in this newsletter, but we will explore them in their broader sense so that we at least get a feel for what the answer is to all of these questions -- at least enough so that you can make decisions as to whether or not you want to buy any farm raised seafood.
That said, the first defining characteristic of fish farming, and one that answers several of the above questions, is whether the fish farm is "extensive" or "intensive." (When it comes to fish farming, these terms have very specialized meanings.)
Intensive Fish Farming VS Extensive Fish Farming
In an intensive fish farm, no significant natural feed is used. Virtually all of the feed is manmade and the fish are fed by hand or machine. Fish are generally held in high stocking densities (limited by species tolerance) holding units. Theoretically, this allows for the introduction of fewer natural toxins such as mercury.
An extensive fish farm, on the other hand, is dependent on the local natural setting, such as a pond or coastal sea area. The food is natural to the environment, which at first sounds good, but is often augmented by the use of organic and inorganic fertilizers. Fertilization of ponds promotes the growth of simple plants which form the base of the food chain in the pond. Fish stocked in these ponds feed on phytoplankton, zooplankton, bottom-dwelling invertebrates, and smaller fish. Some extensive fish farms, in an attempt to increase production beyond the level supported by the food which is naturally available, even when fertilized, incorporate supplementary feeds. Supplementary feeds range from cereals and agricultural and fishery by-products to formulated feeds. At its most effective, this type of production can be integrated with other types of crop or livestock production, using animal manure and agricultural by-products as sources to stimulate primary production. (More on that in a moment.) The function of the supplemental feeds is to provide extra nutrients to complement those obtained from natural foods. Some species such as tilapia, carp, and catfish are essentially vegetarian and can grow readily in these environments. On the other hand, it should be noted that tilapia in Chinese fish farms are fed pig and goose manure to supplement their diets -- even though they contain salmonella and make the tilapia "more susceptible to disease."5
Carnivorous fish, such as salmon on the other hand, depend on fish feed, of which a portion is usually derived from smaller wild caught marine life (anchovies, menhaden, etc.). As a side note, salmon farming is not "energy" efficient as it requires more tonnage of anchovies, etc. than is harvested in the salmon. In fact, for every one pound of farmed salmon harvested, up to five pounds of smaller fish may be required to produce it -- although some modern fish farms have cut that number down considerably. Unless something changes, this is unsustainable. In that regard, vegetable-derived proteins have successfully replaced fish meal in feeds for carnivorous fishes, but vegetable-derived oils have not successfully been incorporated into the diets of carnivores.
Contained Tanks and Ponds VS Cages
In a contained environment, when you add fertilizer to the water, you run the risk of the algae growing out of control in what is known as algal blooms. When temperatures, nutrient supply, and available sunlight are optimal for algal growth, algae multiply their biomass at an exponential rate, eventually outpacing the ability of the added fertilizer to sustain the alga, leading to an exhaustion of available nutrients and a subsequent die-off. The decaying algal biomass then depletes the oxygen in the pond water and pollutes it, thus leading to a massive loss of fish.
Another problem with contained fish farms is that they require massive water purification systems to provide a continual quantity of fresh, aerated, oxygenated water -- upwards of a million gallons of water per acre/per year. A more eco-friendly option is to make use of hydroponic horticulture to clean up the water so that the requirements for water treatment are greatly reduced. The use of a caged environment obviously bypasses this need by making use of the moving water in the river or sea to continually flush out the waste and provide fresh, oxygenated water. Environmentalists, however, dislike these systems since they carry all the waste and pollution created by the fish into the river or sea -- for all the rest of us to enjoy.
Fish cages are placed in lakes, bayous, ponds, rivers or oceans to contain and protect fish until they can be harvested. Fish cages allow for many more varieties of fish to be raised than contained systems as many types of waters can be used: rivers, lakes, sea coasts, estuaries, filled quarries, etc. Cage farming of fishes in open seas is also gaining popularity. Problems with cage farming include the lack of ability to control water quality, poaching, and cage failure which allows for non-native fish species to escape into the open water and threaten local species. In fact, many open water fish farms operate, not with cages, but with net pens. These systems are fragile and extremely susceptible to being ripped open from predators or storms. When the fish escape, they can cause irreparable harm to the local ecosystems--corrupting gene pools, competing for food sources and breeding territories, and spreading disease.
High Population Density
As already mentioned, high population density in your ponds or cages is required to maximize profits. And as with factory farming of land animals, when you concentrate animals beyond population densities in which they would ever be found in nature, you run several risks. First, the animals start to behave abnormally and will begin to harm each other. In effect, they become anti-social and psychotic. (That's why chickens in factory farms, for example, have their beaks burned off -- so they don't peck and cannibalize each other.6) And then there's the increased risk of rapidly spreading infection by bacteria, viruses, protozoa, fungi, and parasites such as fish lice and intestinal worms. Heavy antibiotic dosing and the use of chemical pesticides7 are often incorporated to help manage these problems.
The net result is that farmed raised fish can have significantly higher levels of a whole range of toxins when compared with wild caught fish. This is very dependent, of course, on where the fish are raised, the practices used in raising them, and government regulation and enforcement that govern the fish farm. In one study, for example, researchers found levels of 14 toxins including PCBs, dioxins, dieldrin, and toxaphene that were significantly elevated in both European and North American farm-raised salmon when compared with wild Pacific salmon.8 On the other hand, levels of only six toxins were significantly elevated in South American farm-raised salmon. Levels of two toxins (HCB and lindane) were actually significantly lower in farm-raised South American salmon than in wild salmon species. Take that America and Europe!
Sea lice are small marine parasites that occur naturally, but at very low levels, on many different species of wild fish including wild adult salmon. Like algae, sea lice are planktonic, meaning they travel by floating with the tide. When they encounter fish, they attach themselves, usually on the skin, fins, and/or gills and feed off the mucous or skin. Large numbers of highly populated, open-net salmon farms can create exceptionally large concentrations of sea lice in the waters surrounding the farms. Wild salmon are then exposed to these lice as they make their way from their natural spawning grounds further up river and pass through the river estuaries where the open-net farms are located. Many young wild salmon are infected and do not survive as a result. An infestation of as few as one to three lice can kill a young salmon. Thanks to fish farms, the louse-induced mortality of pink salmon in some regions is commonly over 80%, and in some case can reach 95%.9 The problem is that some species of sea lice actually target farm raised fish (made much easier because they are raised so close together). From there, they easily migrate to the population at large when they comingle during spawning season or when farmed fish escape from their pens -- causing wild salmon populations to diminish by 50% a year!10 For most fish farm operations, heavy use of antibiotics are the answer -- but that's no help to the wild populations, and for that matter, infested farm fish populations can still die at rates exceeding 30%. As a side note, the antibiotics cause diseases to mutate and these mutant strains are released into the oceans exposing wild stocks. A number of viral, fungal, and bacterial infections have been passed to wild stock as a result of fish farms.11
The Nutritional Values of Farmed VS Wild Caught Fish
According to the fish farmers, numerous studies have proven that farmed fish and wild caught fish are nutritionally equivalent. And that's probably true as long as you are selective as to which nutrients you look at. A basic analysis of proteins, fats, carbohydrates, and a handful of key vitamins finds little difference. For example:
- Farmed salmon has 178 calories per 100 grams, whereas wild salmon has 216 calories. On the other hand, farmed catfish has 119 calories for a 100 gram serving whereas wild catfish has 95 calories per 100 grams.
- When it comes to protein, farmed raised salmon provides 22 grams of protein per 100-gram serving whereas wild salmon provides 26 grams. Farmed catfish likewise comes in a little less at 15 grams VS 17 grams for wild caught. Both differences are statistically notable, but not so much nutritionally.
- And when it comes to minerals, the differences again are also marginal. Farmed catfish contains 19 mg of magnesium and 302 mg of potassium per 100 grams VS 23 and 358 for wild caught.
So far, so good! But when we look at the essential fatty acids, we get a different story. Yes, farmed fish have as much omega-3's as wild caught (and sometimes even more because they are flabbier and don't burn it off swimming in the ocean), but they also have substantially more pro-inflammatory omega-6's. And as I have pointed out on numerous occasions, it's not the amount of omega-3's in your diet that makes you healthy; it's the ratio of omega-6 to omega-3. The more omega-6 you get in your diet, the more omega-3's you need to balance it out. The better ratio in wild caught salmon is much healthier than the omega-6 skewed ratio in farmed salmon.
And then there's the issue of color. Wild salmon feeds on krill, which provides the bright red/orange color that we associate with salmon. That color is not just pretty; it's associated with a much higher level of carotenoid antioxidants. Farmed salmon does not eat krill, but it does get some carotenoids such as astaxanthin and canthaxanthin added to its feed pellets to color the flesh. Essentially, it's the same process. There are no synthetic dyes involved. And yet! Wild salmon tends to be darker in color than its farmed raised equivalent of the same species. Why? Well, it's the same as with human diets -- food sourced vitamins and antioxidants tend to be more easily utilized and more effective than isolated forms in pills. The bottom line is that wild caught fish tends to be higher in antioxidants no matter what its natural color.
And then there's the issue of toxicity. Wild caught fish tends to be higher in natural toxins such as heavy metals (think mercury), whereas farmed raised fish tends to be higher in manmade toxins such as PCB's and antibiotics. At least with wild fish, you can pick your species (such as salmon) to minimize your exposure to heavy metals. With farm raised fish, you're stuck with what they put in the water to make their fish grow and stay alive.
Inhumane Treatment of Fish
In the United States, there are no regulations to ensure the humane treatment of fish. Do fish warrant humane treatment? I suppose that depends on your point of view…or frame of reference, as it were. On the other hand, in answer to the question "Do fish suffer?" the answer is an unequivocal "yes" and that's easily observed in their behavior.
We've already talked about the crowded conditions that farmed fish are raised in. Specifically, to maximize profits, fish farms cram as many fish as possible into their pens. Typically, on a salmon farm, a 2.5-foot fish spends its entire life in a space the size of a bathtub. Trout farms are even more crowded, with as many as 27 full-grown fish in a bathtub-sized space. One of the arguments used to explain this away is that fish swim in close quartered schools anyway so that the tight spaces are normal for them. That is, if you forgive the pun, a specious argument. First, there is a vast, vast difference between wandering the limitless oceans in close formation with other fish in organized schools and being confined to a tiny space. If you doubt that, consider the difference between voluntarily going to a crowded dance club where the bodies are literally pressed against each other for a night of hedonistic fun and living out your entire life in a 6'x8' prison cell with two other convicts. Keep in mind that you actually have more personal space in a prison cell, but which environment would you rather be in…and which is likely to drive you crazy?
As PETA says, "Because they are designed to navigate vast oceans and use all their senses to do so, many fish go insane from the cramped conditions and lack of space on fish farms. The tight enclosures inhibit their ability to navigate properly and cause them to knock against each other and the sides of the enclosures. This jostling causes sores and damage to their fins."
As many as 40 percent of farmed fish die before harvesting.
Harvesting the Fish
All forms of fishing are inherently cruel. Even if you fish by line, you usually kill the fish by allowing it to suffocate once you pull it out of the water. One only needs to watch a fish flopping around on the shore, gasping for air, to realize that it's not a pleasant way to go. Then again, not many fish die of old age in their beds either. Most fish in the ocean either succumb to disease or predators. As Little Orphan Annie says, "It's a hard knock life."
That said, the standard methods of slaughter for farm fish are an order of magnitude worse. These include:
- Similar to the way line fish die flopping on your boat, many fish farms rely on air asphyxiation -- pulling the fish en masse out of the water and dumping them in massive piles to die. This amounts to suffocation in the open air. The process can take upwards of 15 minutes to induce death, although unconsciousness typically sets in sooner.
- Large fish, such as salmon, are sometimes bashed on the head with a wooden bat called a "priest," and many are seriously injured but still alive and suffering when they are cut open. Smaller fish, such as trout, are often killed by simply draining water away and leaving them to slowly suffocate or by packing them in ice while they are still completely conscious.
- Smaller farmed fish are sometimes chilled on ice or submerged in near-freezing water. The purpose is to dampen muscle movements by the fish and to delay the onset of post-death decay. However, it leaves them fully conscious and increases their sensitivity to pain as evidenced by elevated levels of cortisol. Because fish are coldblooded, allowing them to suffocate on ice prolongs their suffering. Death by this method can take as long as 15 minutes.
- And in some cases, nothing is done. Fish are simply sent down the slaughter line fully alive and conscious. Then while they are fully conscious, their gills are cut, and they are left to bleed to death, convulsing in pain. In the trade, this is known as "exsanguination without stunning." Fish can literally be left writhing for an average of four minutes, and some catfish still respond to noxious stimuli after more than 15 minutes.
I know everyone is up in arms about GMO foods right now, but in fact, genetic modification has been taking place for centuries. Yes, it's been done through crossbreeding and within the limitations of nature VS in a laboratory. But keep in mind, just because it was done naturally doesn't necessarily make it healthy. Killer bees are one example. Another example would be modern forms of wheat -- even organic. Today's wheat is higher in gluten and giladin than its ancestors. These highly allergenic proteins have been deliberately bred into modern wheat to give it better binding properties for baking. Unfortunately, it makes them a whole lot less healthy. And likewise, not all laboratory GMO is harmful. That said, there is plenty of reason to be wary of GMO foods, simply because there is no limit as to what can be done.
Which brings us to fish. Although no GMO fish have been approved by the FDA for consumption yet, they are eventually coming to a store and restaurant near you as surely as money follows politicians. Already, salmon have been modified to produce more growth hormone, which allows them to grow to full size in half the time.12 The companies involved claim they are safe and that there is no environmental risk as these salmon have been "created" to have sterile eggs that can only be grown in tanks on land.13 And yet, somehow, I can't help but be reminded of Jeff Goldblum's line from Jurassic Park, "Life finds a way."
Another problem is that the GMO salmon are more sexually aggressive. If it escapes into the ocean, it would dominate the wild males when it comes to mating. But since they're sterile, no babies would result. Theoretically, then, this could result in the complete elimination of wild salmon over several generations. It should be noted that the AquAdvantage® salmon has been under review since 1995 without being approved. However, in 2010, an FDA scientific advisory panel evaluated 21 years of data on the fish and deemed it safe for the environment and human consumption. As of this date, the FDA has not given final approval, but it's only a matter of waiting for a more suitable political environment.14
Shell Fish Farms
We've focused on fin fish farming in this newsletter, but it's probably worth mentioning that wild caught shrimp only account for some 10 percent of the shrimp you purchase in the grocery store or at restaurants. Ninety percent is farmed, and most of it is imported from India, Thailand, Vietnam, and China. Regulations there are not quite what most of us would look for. Then again, since the oil spill in the gulf, is wild caught shrimp any healthier?
Then again, in Vietnam, according to a Bloomberg article, farmed shrimp bound for the US market are kept fresh with heaps of ice made from tap water that teems with pathogenic bacteria. 15 That same Bloomberg article also notes that at the same company "there's trash on the floor, and flies crawl over baskets of processed shrimp stacked in an unchilled room." In May, ABC News bought 30 samples of imported farmed shrimp from across the country and had them tested for antibiotic traces.16 Three of the samples contained the banned antibiotics: enrofloxacin, an antibiotic banned in animals that Americans eat because it damages the immune system; chloramphenicol, suspected to cause cancer in humans; and the carcinogen nitrofuranzone, which was banned in the U.S. 40 years ago.
"Shrimp farming is also one of the most destructive types of aquaculture. Mangrove forests protect coastlines, provide food and shelter to countless wildlife, and supply multiple resources to impoverished coastal people who rely on them for daily sustenance. Unfortunately, they also occupy many ideal locations for shrimp farming, and are uprooted and destroyed as a result. In addition, shrimp farmers are often quick to abandon the locations and move to new ones for better production results, destroying more mangroves along the way. Shrimp farms also raise the salinity of surrounding water and soil, ruining the land for agriculture."17
Oysters and mussel farms, on the other hand, are surprisingly environmentally friendly. Because they are filter feeders, oysters and mussels actually make the water in their ecosystem cleaner, and due to their lack of mobility, they are much easier to contain than fish.
Unfortunately, as I mentioned at the top of the newsletter, fish farming is only going to keep growing. As the millions of people in third world countries improve their economic situation, they want access to animal protein. Morality and health issues aside, it's inevitable. Given that, and given that there are limits as to how much meat, chicken, and pork can be raised on land, and given the fact that wild fish populations are plummeting, the curve for fish farming has only one direction to go…up. In fact, the United Nations' Food and Agriculture Organization said as much when they said that the aquaculture industry is growing three times faster than land-based animal agriculture, and that aquafarms will become even more prevalent as natural fisheries become exhausted.
Given its inevitability, the question, then, is how to make it "tolerable." And the answer is several steps:
- We need to control the chemicals that are used in fish farming. Many of chemicals banned in the US are still used in international fish farms for disease and parasite control. Due to a lack of regulation, these chemicals make their way onto our dinner tables through the large amount of fish we import from other countries. On the other hand, as we mentioned above, some countries -- notably in South America -- actually produce less contaminated farmed fish than in the U.S.
- If GMO fish is inevitable, which it probably is, then we at least need some way to control what modifications are allowed -- and GMO fish should absolutely be labeled as such. It also must be part of a comprehensive GMO labeling law -- preferably international, but at least countrywide.
- We need some group that people can trust (and it's not the FDA or the USDA) to monitor the farmed fish coming into the country that can reliably certify it. Keep in mind that the US Government only has the resources to inspect about 2% of all the farmed fish imported into the United States, and other countries are no better. Unfortunately, relying on suppliers to oversee their own compliance with safety standards and labeling isn't always helpful in distinguishing what's healthy and what isn't and what's farmed and what's wild. The fraudulent labeling of fish for human consumption is essentially pandemic -- with some studies indicating that nearly half of all fish are mislabeled.18 As they say in the South, "That dog won't hunt."
- As part of certification, we need to mandate more humane methods for raising the fish and more humane methods for harvesting them. Electric stunning, for example, when done properly, can render fish unconscious and pain free before processing, and the costs involved are marginal.
- As a world population, we need to modify our tastes away from predator fish such as salmon that require more animal protein in their diet than they produce as food. Continuing down that road is a mathematical dead end. Vegetarian fish like tilapia, on the other hand, are energy/food efficient -- and I think we can keep the pig poop out of their diet. "As Paul Greenberg puts it in his book Four Fish, we may be raising the wrong species. Instead of carnivores like salmon or tuna, we should be farming species that are naturally better adapted to aquaculture--like the vegetarian species tilapia, or arctic char, which tastes like salmon but can be raised in close quarters, reducing the impact on the surrounding environment. Instead of trying to change the fish to our tastes, maybe we should try changing our tastes to fit the fish."19
- And finally, we need to make sure that our certification procedures account for environmental factors. The technology has already been developed for clean fish farming, and is already in use. It is possible to set up a fish farm that processes waste, purifies the water leaving the farm, and protects the environment. For example:
The bottom line is that since fish farming, despite its major problems, is here to stay, we need to make it better rather than tilt at windmills hoping it will go away. It won't. We need a certification authority like the California Certified Organic Farmers -- at least before USDA took that over the word "organic" and corrupted it--to watch over the industry and hold its feet to the fire.
- 1. Herminio R. Rabanal "History of aquaculture." Fisheries and Aquaculture Department, United Nations. 24 March 1988. (Accessed 26 Oct 2012.) http://www.fao.org/docrep/field/009/ag158e/AG158E02.htm
- 2. Gunther, R.T. "The oyster culture of the ancient Romans." Journal of the Marine Biological Association of the United Kingdom, 1897 4 (4). pp. 360-365. (Accessed 26 Oct 2012.) http://sabella.mba.ac.uk/171/01/The_oyster_culture_of_the_Ancient_Romans.pdf
- 3. A commonplace book. Halesowen Abbey.(Accessed 26 Oct 2012.) http://office23.jimdo.com/gazetteer/sacred-sites/halesowen-abbey/
- 4. "Earth: A Graphical Look at the State of the World." The Global Education Project. (Accessed 30 Oct 2012.) http://www.theglobaleducationproject.org/earth/fisheries-and-aquaculture.php
- 5. Nguyen Dieu Tu Uyen and William Bi. "Asian Seafood Raised on Pig Feces Approved for U.S. Consumers." Bloomberg Markets Magazine. 10 Oct 2012. (Accessed 30 Oct 2012.) http://www.bloomberg.com/news/2012-10-11/asian-seafood-raised-on-pig-feces-approved-for-u-s-consumers.html
- 6. Ohiorganic. "Why do factory farms cut off hens beaks?" Yahoo Answers. 2009. (Accessed 31 Oct 2012.) http://uk.answers.yahoo.com/question/index?qid=20100421095053AArXAQ4
- 7. Severin Carrell. "Scottish fish farmers use record amounts of parasite pesticides." The Guardian, 10 September 2012. (Accessed 29 Oct 2012.) http://www.guardian.co.uk/environment/2012/sep/10/scottish-fish-farmers-parasite-pesticide
- 8. Erik Stokstad. "Salmon Survey Stokes Debate About Farmed Fish." Science 9 January 2004: 154-155. http://www.sciencemag.org/content/303/5655/154.1.summary
- 9. Krkošek, M., M.A. Lewis, A. Morton, L.N. Frazer, J.P. Volpe. "Epizootics of wild fish induced by farm fish." Proceedings of the National Academy of Sciences 2006 103:15506-15510. http://www.pnas.org/content/103/42/15506.full
- 10. Ford JS and Myers RA. "A Global Assessment of Salmon Aquaculture Impacts on Wild Salmonids" PLoS Biol, 2008 6(2): e33. http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.0060033
- 11. Fish Farms." Union of BC Indian Chiefs. (Accessed 30 Oct 2012.) http://www.ubcic.bc.ca/Resources/fishfarmpaper.htm#ixzz2ApVJ8Rb8
- 12. AquAdvantage® Fish." AquaBounty Technologies. (Accessed 31 Oct 2012.) http://www.aquabounty.com/products/products-295.aspx
- 13. April Fulton. "Biotech Battle: Are Genetically Engineered Fish Safe?" NPR. 20 Sept 2010. (Accessed 31 Oct 2012.) http://www.npr.org/templates/story/story.php?storyId=129939819
- 14. Amy Maxmen. "Politics holds back animal engineers." Nature. 17 Oct 2012. (Accessed 31 Oct 2012.) http://www.nature.com/news/politics-holds-back-animal-engineers-1.11596
- 15. Nguyen Dieu
- 16. Jim Avila. "Antibiotics Illegal in the US Found in Samples of Foreign Shrimp." abc News. 14 May 2012. (Accessed 30 Oct 2012.) http://abcnews.go.com/Health/antibiotics-illegal-us-found-samples-foreign-shrimp/story?id=16344514
- 17. Will Burson. "Fish Farms." Hippocrates Health Institute. 6 Sept. 2012. (Accessed 29 Oct 2012.) http://www.hippocratesinst.org/2012-09/fish-farms
- 18. Kera Abraham. "Seafood fraud disguises farmed salmon as wild, tilapia as snapper and sole as sand dabs." Monterey County Weekly. 2 August 2012. (Accessed 30 Oct 2012.) http://www.montereycountyweekly.com/news/2012/aug/02/something-fishy/
- 19. Bryan Walsh. "Food: Why the Debate Over GM Salmon Misses the Point." Time. Sept. 21, 2010. (Accessed 31 Oct 2012.) http://science.time.com/2010/09/21/food-why-the-debate-over-gm-salmon-misses-the-point/