A New York Times article (Pollack 2010) appeared on Tuesday, September 21, 2010, and discussed whether or not specially genetically engineered farmed salmon might be approved for sale in the US. There were representatives of the aquaculture industry and of the firm pushing the idea, AquaBounty Technologies, speaking in support before an FDA panel, and a number of special environmentalist or consumer’s groups going on record as against the idea in general, or some particular aspect that they felt was underexplored or held potential danger.
The critics brought up a number of issues that were treated as being so important of themselves, that the approval process should be delayed or cancelled altogether. But such a single-issue-based disapproval sometimes overlooked other factors and realities of salmon ecology, economics, and even human medicine, when a more holistic and interdisciplinary view of the risks and benefits of this AquAdvanatge™ salmon and its method of being aquacultured might be more revealing.
What’s the big deal with salmon?
Salmon now leads in US sales of all fresh, refrigerator case finfish in supermarkets and is the third most consumed seafood product just behind frozen shrimp and canned tuna (National Fisheries Institute 2009). It’s considered to be particularly good for you. It is nationally promoted, responsibly endorsed, and widely perceived as having health benefits, especially its polyunsaturated fats and omega-3 fatty acid content (Harel et al 2001, Horrocks & Yeo 1999) that outweigh its risks from mercury for most categories of consumers (Foran et al 2005, Smith & Guentzel 2010). Demand is expected to grow in the restaurant and institutional food service trade not the least because salmon is one of the most popular types of sushi and sashimi among both high school (FoodServiceDirector 2010) and college age consumers (Boss 2009).
Why do they farm salmon anyway? Can’t we just catch more wild salmon in the ocean?
Atlantic salmon are still caught in the wild, but their reproductive carrying capacity has long ago been reached, and Atlantic salmon fisheries have basically harvested (and often polluted) themselves out of business in many locales, including most of New England, formerly a rich salmon fishing area. Indeed most wild Atlantic salmon served in the US has been imported from Canada, the UK, or Scandinavian countries, but even so, catches have been declining: In 1996 we imported 566 tons of wild caught salmon, but by 2008 that amount was down to 58 tons.
It should be noted that while the Alaskan wild salmon fishery ----involving a number of different salmon species but not the Atlantic salmon----remains reasonably healthy, the other West coast native salmon fisheries running from Northern California through to British Columbia, have been in severe decline owing to overfishing and environmental calamities, and thus will not provide a ready, sustainable alternative in the future (US Fish & Wildlife Service 2010). The only realistic alternative source for a growing demand for salmon is to use aquacultured salmon.
Can’t we just stock the rivers with more salmon from salmon hatcheries, and let them grow up in the wild in the ocean and have them return to the rivers where we stocked them, just like wild salmon do?
This is being done in Alaska and Northern Europe with some success (and in the Great Lakes although the population cannot reproduce there) but there are still problems: The stocked fish generally behave like escaped farmed fish and sometimes out-compete the wild fish, and it is not always clear that wild and stocked fish interbreed successfully, even though they are of the same species. This means that it is sometimes possible to end up, not with an overall increase in the total number of available salmon, but rather the displacement of one type of salmon by another without any net gain in salmon supply. (Crozier 1993, Erkinaro et al 2010, Skaala, Glover & V. Wennevik 2006, Soto, Jara & Moreno 2006, Uusitalo, Kuikka & Romakkaniemi 2005).
Why do they want to genetically engineer a naturally perfectly good fish in the first place?
The principal reason is that these fish, when farmed, grow to harvest size in about half the time as non-genetically-engineered farm-raised salmon, and that this quick turnaround time means that they can be economically grown in closed aquatic systems, meaning not in pens in the open ocean or nearby brackish waters, but rather in clean artificial ponds much like modern American catfish farming, ponds or tanks which do not connect to rivers or the ocean. As seen in the catfish farming industry (Stankus 2010), many more variables regarding fish wholesomeness and taste, water quality, the presence of parasites and diseases, the management of waste products, are much more controllable, although realistically never perfectly controllable, in such closed systems. Salmon farming in a closed system represents a serious incremental improvement in the food safety, economics and as we will see shortly, in the environmental impact of salmon aquaculture. Genetically modified salmon raised in closed systems will go a long way to exploding the simplistic folkloric natural foods ideology that Norwegian fisheries researcher Oivind Bergh (2007) calls the dual myth: That wild fish are always healthier (and therefore always better for you) and that farmed fish are always unhealthy (and therefore always worse for you).
How do these genetically modified salmon grow so fast?
Basically, two genes have been inserted into their genomes. One gene simply enables internal growth hormone production year round despite the cold (salmon ordinarily stop making growth hormone in cold weather and therefore stop growing during winter months). The second gene basically enables the first gene to activate and do its work.
Most importantly, no hormones that are not native to fish are introduced to this fish, nor are they fed hormones in their rations. There is no reasonable scientific basis for suggesting that these fish are somehow hormonally disruptive of humans or other animals that might eat them, or even that the enhanced growth hormone production, is damaging to the fish themselves, the arguments used against hormones given to livestock and dairy cows through feed or direct injection.
Why can’t we just wait for the traditional growing out period of non-genetically engineered salmon farmed in bays and estuaries?
There are at least three reasons that make quicker growing farmed salmon, grown in closed systems, a better idea than farmed non-genetically modified salmon raised in sea pens.
The first is ironically ecological or environmental: Salmon farmed in the traditional manner in pens in bays and estuaries tend to become infested with sea lice, which, while not known to be harmful to humans, stunt the growth and well-being of the salmon being farmed. Unfortunately, once the sea lice find themselves a fertile home base, such as the trapped farmed salmon, they spread, not only to nearby wild salmon, but to other fish species as well, sometimes decimating their number(Costello 2009, Frazer 2009).
The second is also ecological and environmental: The sea floor beneath and areas surrounding sea pens are typically fouled with fecal products, uneaten food, and trace chemicals used to keep the cages from becoming coated with barnacles, weeds, and the like. Perversely, the increased organic matter in the waters near the cages actually decreases the oxygen levels in the water as well as the number of toxic compounds in the immediate area by binding with agents that would otherwise remain in solution and generally in a diluted state (Musclow 2005, Mayor et al 2010). See the following for more details.
The third reason is also environmental but includes some clinical implications as well: Quicker growing fish raised in closed aquatic systems with closely monitored water quality show demonstrably lower rates of bioaccumulation of environmental toxins including heavy metals, runoff fertilizer compounds, and especially trace pharmaceuticals like antibiotics used to suppress assorted bacterial and fungal infections in salmon penned up in bays and estuaries (Burridge 2010, Cabello 2006, Fortt, Cabello & Buschman 2007). These materials are not only generally bad for the sea life around them, but, should they accumulate within human consumers, poisonous and potential enablers of diminished antibiotic effectiveness, as they encourage the proliferation of drug resistant bacteria in the environment (Herwig, Gray & Weston 1997).
What will happen to wild salmon if these genetically engineered fish somehow escape their closed systems and mate with natural salmon populations?
First, at least as currently planned in terms of their major sites of production, the salmon will be raised in places where even the nearest sea and river waterways are seriously unfavorable to them, so it is likely that they would die out because they were in such unsupportable circumstances.
Second, all of these fish are females, and by design, about five out of every six are demonstrably sterile. Such a sex ratio and high rate of infertility does not bode well for them to be able to establish a viable invasive population which can compete with local, native fish. (Which generally do not include members of the salmonid family with which they could conceivably try to mate.)
What about possible allergic reactions?
It is unfortunately true that there are a great many people allergic, and sometimes severely so, to proteins in seafood, including proteins in Atlantic salmon (Pitsios et al 2010). However, there is as yet no evidence that the two genes that have been inserted into these AquaAdvantage Atlantic salmon will cause the production of any proteins that are not already likely to be in any other type of Atlantic salmon. A safe and sensible recommendation would be for people who are known to be allergic to Atlantic salmon not to eat any Atlantic salmon, AquAdvantage type or not, and for the rest of us to eat available Atlantic salmon including AquAdvantage salmon when we want to, because we like it and it is a generally healthy food.
Shouldn’t there be warning labels on such salmon?
Given that there are no known differences in the food safety or nutritional value of these salmon, there is no scientific justification for putting any kind of warning label on them. It might be fair to consumers who, for whatever reason, prefer wild-caught salmon or farmed salmon, to have the salmon labeled simply as wild-caught or farm raised salmon, and mention the country of origin. This is pretty much the standard procedure in most supermarkets anyway, and as noted below, seems to have little effect on sales. People buy what looks good to them at the lowest price they can get.
Are there any foreseeable disadvantages to genetically modified salmon of this type raised by this method?
Overexpectation, too much “hype” in terms of certain ecological and economic impacts is about the only forseeable problem.
At least three pre-existing dilemmas will likely persist despite the adoption of this genetically modified salmon and its method of being raised, but these dilemmas would also continue without them.
1. Detrimental impact on the global population of small fish and supply of fish byproducts. While all the science thus far suggests that with proper care, these fish can be raised safely within closed systems with virtually no risk to the local fish population by direct invasion of their waterways and competition for food within them, problems remain with the need of all carnivorous fish (and this includes salmon, farmed or wild) for smaller forage fish, usually caught in the wild to be turned into fish meal for the pellets fed to the salmon, and this can cause population declines in fish that would feed other fish in the wild or feed humans (think anchovies and sardines, for example) directly (Aubin et al 2009, Ayer et al 2009, Mullon et al 2009, Pelletier et al 2009).
2. This new type of salmon and way of producing it will not likely produce a great many more jobs in the poorer countries that host these or any other modern aquaculture operations. Unemployment in the poorer countries where this type of aquacultured salmon (and any other type of aquacultured salmon) will not dramatically decrease, because operations such as these are much efficient in their use of manpower, particularly when compared to the still large numbers of increasingly impoverished local traditional fisherfolk attempting to land ever diminishing catches. This is not to say that the fewer workers in modern farmed fishing would not, in the long run, be better off, particularly if there was a requirement that these international aquaculture companies hire and train displaced local fisherfolk, instead of bringing in alien crews for permanent operations (Adeel & Safriel 2008, Grigorakis et al 2010 ).
3. This new type of salmon and way of producing it will not likely increase the availability of low-cost, high-quality protein in the poorer countries that host these and any other modern aquaculture operations. Barring “set-aside-some for domestic use” legislation in the countries in which these operations are set up, the local population will probably not have greatly increased access to cheap salmon for their own consumption. The overwhelming share of farmed (and wild caught) salmon is sold on the international market as a cash crop to wealthy, highly developed countries like the US, and their consumers tend to buy the lowest priced salmon of comparable quality and freshness, regardless of which country was the source (Wozniak 2010).
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Adeel, Zafar, and Uriel Safriel. 2008. Achieving sustainability by introducing alternative livelihoods. Sustainability Science 3 (1) (APR): 125-33.
Adhikari, S., L. Ghosh, S. P. Rai, and S. Ayyappan. 2009. Metal concentrations in water, sediment, and fish from sewage-fed aquaculture ponds of Kolkata, India. Environmental Monitoring and Assessment 159 (1-4) (DEC): 217-30.
Alderman, D. J. 2002. Trends in therapy and prophylaxis 1991-2001. Bulletin of the European Association of Fish Pathologists 22 (2): 117-25.
Aubin, J., E. Papatryphon, H. M. G. van der Werf, and S. Chatzifotis. 2009. Assessment of the environmental impact of carnivorous finfish production systems using life cycle assessment. Journal of Cleaner Production 17 (3): 354-61.
Ayer, Nathan, Raymond P. Cote, Peter H. Tyedmers, and J. H. Martin Willison. 2009. Sustainability of seafood production and consumption: An introduction to the special issue. Journal of Cleaner Production 17 (3): 321-4.
Bergh, Oivind. 2007. The dual myths of the healthy wild fish and the unhealthy farmed fish. Diseases of Aquatic Organisms 75 (2): 159-164.
Bernhisel-Broadbent, J, D Strause, and H A Sampson. 1992. Fish hypersensitivity. II: Clinical relevance of altered fish allergenicity caused by various preparation methods. The Journal Of Allergy And Clinical Immunology 90 ( 4 Pt 1): 622-629.
Boss, Donna L. 2009. College dining services tap into international street cuisines. Nation's Restaurant News 43 (27): 22.
Burridge, Les, Judith S. Weis, Felipe Cabello, Jaime Pizarro, and Katherine Bostick. 2010. Chemical use in salmon aquaculture: A review of current practices and possible environmental effects. Aquaculture 306 (1-4) (AUG 15): 7-23.
Cabello, F. C. 2006. Heavy use of prophylactic antibiotics in aquaculture: A growing problem for human and animal health and for the environment. Environmental Microbiology 8 (7) (JUL): 1137-44.
———. 2004. Antibiotics and aquaculture in Chile: Implications for human and animal health. Revista Medica De Chile 132 (8) (AUG): 1001-6.
Capone, D. G., D. P. Weston, V. Miller, and C. Shoemaker. 1996. Antibacterial residues in marine sediments and invertebrates following chemotherapy in aquaculture. Aquaculture 145 (1-4) (OCT 15): 55-75.
Cole, David W., Richard Cole, Steven J. Gaydos, Jon Gray, Greg Hyland, Mark L. Jacques, Nicole Powell-Dunford, Charu Sawhney, and William W. Au. 2009. Aquaculture: Environmental, toxicological, and health issues. International Journal of Hygiene and Environmental Health 212 (4) (JUL): 369-77.
Costello, Mark J. 2009. How sea lice from salmon farms may cause wild salmonid declines in Europe and North America and be a threat to fishes elsewhere. Proceedings of the Royal Society B-Biological Sciences 276 (1672) (OCT 7): 3385-94.
Cottee, Stephanie Yue, and Paul Petersan. 2009. Animal welfare and organic aquaculture in open systems. Journal of Agricultural & Environmental Ethics 22 (5) (OCT): 437-61.
Crozier, WW. 1993. Evidence of genetic interaction between escaped farmed salmon and wild Atlantic salmon (Salmo salar L.) in a Northern Irish river. Aquaculture 113, (1-2): 19-29.
Erkinaro, J., E. Niemelae, J-P Vaehae, CR Primmer, S. Broers, and E. Hassinen. 2010. Distribution and biological characteristics of escaped farmed salmon in a major subarctic wild salmon river: Implications for monitoring. Canadian Journal Of Fisheries And Aquatic Sciences/Journal Canadien Des Sciences Halieutiques Et Aquatiques 67, (1): 130-142.
FoodService Director. 2010. School District Dishes Up Sushi. FoodService Director 23(5): 8.
Foran, Jeffery A, David H Good, David O Carpenter, M Coreen Hamilton, Barbara A Knuth, and Steven J Schwager. 2005. Quantitative analysis of the benefits and risks of consuming farmed and wild salmon. The Journal Of Nutrition 135 (11): 2639-2643.
Fortt, Antonia, Felipe Cabello, and Alejandro Buschmann. 2007. Residues of tetracycline and quinolones in wild fish living around a salmon aquaculture center in Chile. Revista Chilena De Infectologia 24 (1) (FEB): 14-8.
Frazer, L. Neil. 2009. Sea-cage aquaculture, sea lice, and declines of wild fish. Conservation Biology 23 (3) (JUN): 599-607.
Grigorakis, Kriton. 2010. Ethical issues in aquaculture production. Journal of Agricultural & Environmental Ethics 23 (4) (AUG): 345-70.
Harel, Z, S Riggs, R Vaz, L White, and G Menzies. 2001. Omega-3 polyunsaturated fatty acids in adolescents: knowledge and consumption." The Journal Of Adolescent Health 28 (1): 10-15.
Hargrave, Barry T., Lisa I. Doucette, Kats Haya, Faron S. Friars, and Stephen M. Armstrong. 2008. A micro-dilution method for detecting oxytetracycline-resistant bacteria in marine sediments from salmon and mussel aquaculture sites and an urbanized harbour in Atlantic Canada. Marine Pollution Bulletin 56 (8) (AUG): 1439-45.
Herwig, R. P., J. P. Gray, and D. P. Weston. 1997. Antibacterial resistant bacteria in surficial sediments near salmon net-cage farms in Puget Sound, Washington. Aquaculture 149 (3-4) (MAR 31): 263-83.
Horrocks, L A, and Y K Yeo. 1999. Health benefits of docosahexaenoic acid (DHA). Pharmacological Research 40, (3): 211-225.
Lu, X. W., Z. Dang, and C. Yang. 2009. Preliminary investigation of chloramphenicol in fish, water and sediment from freshwater aquaculture pond. International Journal of Environmental Science and Technology 6 (4) (FAL): 597-604.
Mayor, Daniel J., Alain F. Zuur, Martin Solan, Graeme I. Paton, and Ken Killham. 2010. Factors affecting benthic impacts at Scottish fish farms. Environmental Science & Technology 44 (6) (MAR 15): 2079-84.
Meinertz, J. R., G. R. Stehly, and W. H. Gingerich. 1998. Liquid chromatographic determination of oxytetracycline in edible fish fillets from six species of fish. Journal of AOAC International 81 (4) (JUL-AUG): 702-8.
Mullon, C., J-F Mittaine, O. Thebaud, G. Peron, G. Merino, and M. Barange. 2009. Modeling the global fishmeal and fish oil markets. Natural Resource Modeling 22 (4) (NOV): 564-609.
Munoz, Ivan, Maria J. Martinez Bueno, Ana Agueera, and Amadeo R. Fernandez-Alba. 2010. Environmental and human health risk assessment of organic micro-pollutants occurring in a Spanish marine fish farm. Environmental Pollution 158 (5) (MAY): 1809-16.
Musclow, Sandy Lee. 2005. Impact Of Salmon Aquaculture On Sediment Chemistry And Mercury Loading. Master’s thesis. Montreal: McGill University.
National Fisheries Institute (2009). “Top 10 Consumed Seafoods,” https://www.aboutseafood.com/about/about-seafood/Top-10-Consumed-Seafoods
Naylor, Raymond L., Rebecca J. Goldburg, Harold Mooney, Malcolm Beveridge, Jason Clay, Carl Folke, Nils Kautsky, Jane Lubchenco, Jurgenne Primavera & Meryl Williams. 1998. Nature's subsidies to shrimp and salmon farming. Science 282 (5390): 883-887.
Ortega, C., O. Gimeno, V. Blanc, P. Cortes, S. Ania, and M. Llagostera. 2006. Antibiotic susceptibility of strains of Aeromonas salmonicida isolated from Spanish salmonids. Revue De Medecine Veterinaire 157 (8-9) (AUG): 410-4.
Pelletier, Nathan, Peter Tyedmers, Ulf Sonesson, Astrid Scholz, Friederike Ziegler, Anna Flysjo, Sarah Kruse, Beatriz Cancino, and Howard Silverman. 2009. Not all salmon are created equal: Life cycle assessment (LCA) of global salmon farming systems. Environmental Science & Technology 43 (23) (DEC 1): 8730-6.
Pitsios, Constantinos, Anastasia Dimitriou, Efthalia C Stefanaki, and Kalliopi Kontou-Fili. 2010. Anaphylaxis during skin testing with food allergens in children. European Journal Of Pediatrics 169 (5): 613-615.
Pollack, Andrew. 2010. Panel leans in favor of engineered salmon. The New York Times CLX (55170): B3.
Rivera-Ferre, Marta G. 2009. Can export-oriented aquaculture in developing countries be sustainable and promote sustainable development? The shrimp case. Journal of Agricultural & Environmental Ethics 22 (4) (AUG): 301-21.
Ruiz-Zarzuela, I., N. Halaihel, J. L. Balcazar, C. Ortega, D. Vendrell, T. Perez, J. L. Alonso, and I. de Blas. 2009. Effect of fish farming on the water quality of rivers in northeast Spain. Water Science and Technology 60 (3): 663-71.
Sapkota, Amir, Amy R. Sapkota, Margaret Kucharski, Janelle Burke, Shawn McKenzie, Polly Walker, and Robert Lawrence. 2008. Aquaculture practices and potential human health risks: Current knowledge and future priorities. Environment International 34 (8) (NOV): 1215-26.
Skaala, Oe, K. Glover, and V. Wennevik. 2006. Gene flow from escapes reduce survival in wild salmon populations. Fisken og Havet, Saernummer(2): 60-62.
Solensky, Roland. 2003. Resolution of fish allergy: A case report. Annals Of Allergy, Asthma & Immunology 91 (4): 411-412.
Soto, D., F. Jara, and C. Moreno. 2001. Escaped salmon in the inner seas, Southern Chile: Facing ecological and social conflicts. Ecological Applications 11, (6): 1750-1762
Thorstad, E.B., I.A. Fleming, P. McGinnity, D. Soto, V. Wennevik & F. Whoriskey2008. Incidence and Impacts of Escaped Farmed Atlantic Salmon Salmo Salar In Nature. NINA Special Report 36. 110 pp.
U.S. Fish & Wildlife Service. 2010. Wildlife Species Information. Endangered Species: Pacific Salmon, Oncorhynchus spp. https://www.fws.gov/species/species_accounts/bio_salm.html
Uusitalo, L., S. Kuikka, and A. Romakkaniemi. 2005. Estimation of Atlantic salmon smolt carrying capacity of rivers using expert knowledge. ICES Journal of Marine Science 62, (4) (Jun): 708-722
Vega, Mario H., Elizabeth T. Jara, and Mario B. Aranda. 2006. Monitoring the dose of florfenicol in medicated salmon feed by planar chromatography (HPTLC). JPC -Journal of Planar Chromatography-Modern TLC 19 (109) (MAY-JUN): 204-7.
Vizzini, Salvatrice, Cecilia Tramati, and Antonio Mazzola. 2010. Comparison of stable isotope composition and inorganic and organic contaminant levels in wild and farmed bluefin tuna, Thunnus thynnus, in the Mediterranean sea. Chemosphere 78 (10) (MAR): 1236-43.
Wolff, M. 2004. Use and misuse of antibiotics. time to evaluate it beyond humans. Revista Medica De Chile 132 (8) (AUG): 909-11.
Wozniak, Shawn. 2020. Has country of origin labeling influenced salmon consumption? Selected Paper prepared for presentation at the Southern Agricultural Economics Association Annual Meeting, Orlando, FL, February 6-9, 2010. https://ageconsearch.umn.edu/bitstream/56460/2/2010%20SAEA%20Wozniak.pdf
Wu, R. S. S. 1995. The environmental impact of marine fish culture: Towards a sustainable future. Marine Pollution Bulletin 31 (4-12) (APR-DEC): 159-66.