In part one we will
look at the wild vs. farmed controversy. In part 2 we will review the radiation
levels following the Fukushima nuclear disaster.
Most dietary guidelines recommend eating at least two servings of low contaminant fish per week, (American Heart Association, 2016; FDA, 2019; Harvard School of public Health, 2019; WASDOH, n.d.-b). The heart healthy anti-inflammatory omega-3 essential fatty acids EPA and DHA are highest in fatty fish such as salmon, sardines, herring, and tuna. Media is filled with warnings of fish loaded with contaminants, such as mercury from coal fired power plants, polychlorinated biphenols (PCBs) from plastics, polybrominated diphenyl ethers (PBDEs) from flame retardant chemicals, and dichlorodiphenyltrichloroethane (DDT) from pesticides, (WASDOH, n.d.-a). To top it off, on March 11, 2011 a 9.0 magnitude earthquake, the Tohoku, occurred just off the eastern coast of Japan (Holt, Campbell, & Nikitin, 2012). The Fukushima Daiichi nuclear power plant in the Fukushima prefecture survived the shaker but succumbed to the tsunami that followed resulting in a nuclear meltdown and subsequent release of untold tons of contaminated cooling water from the crippled reactors. The radioactive plume rippled across the Pacific Ocean to the west coast of the Americas resulting in consumer fears of irradiated wild fish. Thus, one might turn to farmed fish, however there is much negative press about aquaculture and the reportedly reduced quality farmed fish represent. So, what’s the truth? Are fish over? Let’s take a closer look at wild vs farmed salmon and the fish radiation scare.
Aquaculture
We have greatly overfished the oceans and aquaculture has developed as an answer to that dilemma. According to the 2018 State of the World Fisheries and Aquaculture report by the Fish and Agriculture Organization of the United Nations (FAO) only 59.9 % of the global monitored species are being fished at sustainable levels, (Fish and Agriculture Organization [FAO], 2018). That is a powerful motivator to nod approval to aquaculture. Fish production totaled 171 million tons in 2016, 47% of which (80 million tons) came from aquaculture, (FAO, 2018). Performed globally, about 580 different marine animals are farmed by both commercial producers and poor subsistence fishermen who fish low tech as a means of supporting and feeding their families and relatives, (FAO, n.d.). The objections to aquaculture are contaminants, environmental concerns, and suspected reduced omega-3 content of farmed fish, particularly salmon.
Contaminant studies have mixed outcomes as much is dependent on the source of the fishmeal fed to farmed fish, pen location, as well as adherence to best practice standards, (Kelly, Ikonomou, Higgs, Oakes, & Dubetz, 2008.) What does emerge is that both wild and farmed salmon from the Pacific Northwest have low levels of contaminants, (WASDOH, n.d.-b; Kelly et al., 2008). The same contaminants as found in farmed and wild fish may be found in non-aquatic foods as well as a consequence of man’s activities on his environment. Stricter feed regulations have reduced contamination since early studies were reported in the media and follow-up studies have not reproduced earlier contaminant findings. It is felt that the health benefits of salmon outweigh current levels of contaminant exposure, (Megdal, Craft, & Handelman, 2009; WASDOH, n.d.-b).
Environmental Concerns
There are many environmental arguments about aquaculture. Ocean pens pollute their surroundings and spread disease such as sea lice but abiding by strict regulations helps keep this in check, (WASDOH, n.d.-b). Clearing of Mangrove forests for aquaculture is a threat to the ecosystem which again can be addressed by government regulations and careful thought to pen placement., (Martinez-Porchas & Martinez-Cordova, 2012). Eutrophication resulting from excess feed leads to nitrification and toxic algae blooms but can be controlled by changing the amount, timing, and hydro-stability of the feed as well as moving towards polyculture fish farming, (Martinez-Porchas & Martinez-Cordova, 2012). Norwegian Atlantic salmon escapees have bred with wild Atlantic salmon where the incorporation of domestic DNA may compromise the hardiness, genetic diversity, and adaptability of the wild Atlantic salmon, (Karlsson, 2016). Atlantic salmon cannot breed with Pacific salmon and Pacific salmon are not farmed. The Pacific Northwest (PNW) has had escapees also, however, no runs of Atlantic salmon have ever been identified despite mid-century attempts to establish them, (WASDOH, n.d.-b). Further Atlantic farmed salmon have been somewhat domesticated and do not live long in the wild as they are used to being fed rather than having to acquire food on their own, (WASDOH, n.d.-b). Interestingly, the domestication of Atlantic salmon also means that they have adapted to the stress of such an un-natural habitat and grow larger in captivity than their wild counterparts would in the same circumstances, (Solberg, Skaala, Nilsen, & Glover; 2013; Harvey et al., 2016).
Aquaculture does represent a drain on wild fisheries as 20 million tons of the world’s fish catch is used for fishmeal rather than human consumption and of that, 70% goes to farmed fish, (Cashion, Le Manach, Zeller, & Pauly, 2017). The demand for fishmeal used in salmon aquaculture is approximately 6 million tons per year, (Brady, 2018). Fishmeal was once mostly ground up fish, species that humans did not want to eat referred to as “trash” fish. However, some researchers feel that 90% of the “trash” fish that is used for fishmeal, could be used to feed humans, (Leschin-Hoar, 2017). Aside from the fishmeal being unsustainable, it results in bycatch of endangered animals. Enter insect-based feed. A feed company in the Netherlands has come up with a feed made from Black Soldier fly larva, (Brady, 2018). The upside in addition to reducing demand on feed fish is that the larvae don’t have the toxicant exposures that feed fish have, thus, there will be less contamination in the farmed fish. This replaces the protein from the fish part of fishmeal but doesn’t replace the source of healthy fats. In answer to the need for omega-3s in the fishmeal, algal oil production and subsequent supplementation is proposed for omega-3 fatty acids which should drastically reduce dependence on fish in the fishmeal, (DSM, 2017). Further reduction or perhaps the elimination of fish in fishmeal would go a long way towards restoring global fish population, (Beal et al., 2018).
Omega-3 fatty acids
To reduce the need for fish in the fishmeal, producers began to add grains such as corn and soy. This is problematic as it is species inappropriate and requires the addition of several synthesized enzymes to make it digestible, (DSM, n.d.-b) and it alters the fatty acid profile of the fish, (Sprague, Dick, & Tocher, 2016), however, there is enough fish in the fishmeal that farmed salmon have the equivalent omega-3 as wild, (WASDOH, n.d.-b). Further, algae and algal oil production for fishmeal can supply the needed amino acids and omega-3 fatty acids, and such production facilities are underway, (Beal et al., 2018; DSM, 2017).
Many modifications have been proposed to create low contaminant, sustainable, robust fish farms, but what is needed are government regulations and adherence to best practice standards set by global authorities in all nations, (Martinez-Porchas & Martinez-Cordova, 2012; FAO, 2018). When best practices are observed, farmed fish are a nutritious and affordable dietary option as well as a means of restoring wild populations.
References for Part 1
American Heart Association. (2016). Fish and omega-3 fatty acids. Retrieved from http://www.heart.org/HEARTORG/General/Fish-and-Omega-3-Fatty-Acids_UCM_303248_Article.jsp#.XSC4n-tKiUk
Beal, C. M., Gerber, L. N., Thongrod, S., Phromkunthong, W., Kiron, V., Granados, J., …Huntley, M.E. (2018). Marine microalgae commercial production improves sustainability of global fisheries and aquaculture. Scientific Reports 8(1).
Brady, H. (2018). Why salmon eating insects instead of fish is better for environment. Retrieved from
https://news.nationalgeographic.com/2018/02/salmon-insect-feed-fish-meal-netherlands/
Cashion, T., Le Manach, F., Zeller, D., & Pauly, D. (2017, Feb 13). Most fish destined for fishmeal production are food‐grade fish. Fish and Fisheries 18:837–844. https://doi.org/10.1111/faf.12209
CDC. (2012, March 16) CDC’s second nutrition report: A comprehensive biochemical assessment of the nutrition status of the U.S. population. Retrieved from
https://www.cdc.gov/nutritionreport/pdf/4page_%202nd%20nutrition%20report_508_032912.pdf
Drake, V. J. (2017). Micronutrient inadequacies in the US population: An overview. Retrieved from
https://lpi.oregonstate.edu/mic/micronutrient-inadequacies/overview
DSM. (n.d.-b) Feed cost savings. Retrieved from https://www.dsm.com/markets/anh/en_US/species/species-aquaculture/species-aquaculture-feedcostsavings.html
DSM. (2017, March 8) Press Release: DSM and Evonik establish joint venture for omega-3 fatty acids from natural marine algae for animal nutrition. Retrieved from https://www.dsm.com/corporate/media/informationcenter-news/2017/03/2017-03-08-dsm-and-evonik-establish-joint-venture-for-omega-3-fatty-acids-from-natural-marine-algae-for-animal-nutrition.html
Food and Agriculture Organization, (2018, July 9). Is the planet approaching "peak fish"? Not so fast, study says. Retrieved from http://www.fao.org/news/story/en/item/1144274/icode/
Food and Agriculture Organization. (n.d.). FAO's role in aquaculture: Aquaculture development. Retrieved from http://www.fao.org/aquaculture/en/
Food and Drug Administration. (2019). Advice about eating fish: For women who are or might become pregnant, breastfeeding mothers, and young children. Retrieved from https://www.fda.gov/food/consumers/advice-about-eating-fish
Harvard School of Public Health. (2019). Fish: Friend or foe? Retrieved from
https://www.hsph.harvard.edu/nutritionsource/fish/
Harvey, A. C., Monica, F. S., Troianou, E., Carvalho, G. R., Taylor, M. I., Creer, S., . . . Glover, K. A. (2016). Plasticity in growth of farmed and wild Atlantic salmon: Is the increased growth rate of farmed salmon caused by evolutionary adaptations to the commercial diet? BMC Evolutionary Biology, 16. doi:http://dx.doi.org/10.1186/s12862-016-0841-7
Holt, M., Campbell, R. J., Nikitin, M. B. (2012). Congressional Research Service: Fukushima nuclear disaster. Retrieved from https://fas.org/sgp/crs/nuke/R41694.pdf
Karlsson, S., Diserud, O. H., Fiske, P., & Hindar, K. (2016). Widespread genetic introgression of escaped farmed Atlantic salmon in wild salmon populations, ICES Journal of Marine Science, 73, (10), 2488–2498. https://doi.org/10.1093/icesjms/fsw121
Kelly, B. C., Ikonomou, M. G., Higgs, D. A., Oakes, J. & Dubetz, C. (2008). Mercury and other trace elements in farmed and wild salmon from British Columbia. Environmental Toxicology and Chemistry 27(6).
Kelly, B. C., Ikonomou, M. G., Higgs, D. A., Oakes, J. & Dubetz, C. (2008). Mercury and other trace elements in farmed and wild salmon from British Columbia. Environmental Toxicology and Chemistry 27(6).
Leschin-Hoar. C. (2017, Feb 13). 90 Percent of fish we use for fishmeal could be used to feed humans instead. Retrieved from https://www.npr.org/sections/thesalt/2017/02/13/515057834/90-percent-of-fish-we-use-for-fishmeal-could-be-used-to-feed-humans-instead
Martinez-Porchas, M. & Martinez-Cordova, L. R. (2012). World aquaculture: Environmental impacts and troubleshooting alternatives. The Scientific World Journal 2012 #389623. Doi: 10.1100/2012/389623
Megdal, P.A., Craft, N.A. & Handelman, G.J. (2009). A simplified method to distinguish farmed (Salmo salar) from wild salmon: Fatty acid ratios versus astaxanthin chiral isomers. Lipids 44(6): 569–576. https://doi.org/10.1007/s11745-009-3294-6
Solberg, M. F., Skaala, Ø, Nilsen, F., & Glover, K. A. (2013). Does domestication cause changes in growth reaction norms? A study of farmed, wild and hybrid Atlantic salmon families exposed to environmental stress. PLoS One, 8(1) doi: http://dx.doi.org/10.1371/journal.pone.0054469
Sprague, M., Dick, J., & Tocher, D. (2016). Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006-2015. Nature Scientific Reports 6, 21892. doi: http://dx.doi.org/10.1038/srep21892
Washington State Department of Health. (n.d.-a). Contaminants in fish. Retrieved from https://www.doh.wa.gov/CommunityandEnvironment/Food/Fish/ContaminantsinFish
Washington State Department of Health. (n.d.-b). Farmed salmon vs. wild salmon. Retrieved from https://www.doh.wa.gov/CommunityandEnvironment/Food/Fish/FarmedSalmon
Washington State Department of Health. (n.d.-c). Health benefits of fish. Retrieved from
https://www.doh.wa.gov/CommunityandEnvironment/Food/Fish/HealthBenefits
Photo Credit:
US Environmental Protection Agency. (July 2010). Spawning male sockeye, Public Domain. Retrieved from https://commons.wikimedia.org/w/index.php?curid=51971558
https://lpi.oregonstate.edu/mic/micronutrient-inadequacies/overview
DSM. (n.d.-b) Feed cost savings. Retrieved from https://www.dsm.com/markets/anh/en_US/species/species-aquaculture/species-aquaculture-feedcostsavings.html
DSM. (2017, March 8) Press Release: DSM and Evonik establish joint venture for omega-3 fatty acids from natural marine algae for animal nutrition. Retrieved from https://www.dsm.com/corporate/media/informationcenter-news/2017/03/2017-03-08-dsm-and-evonik-establish-joint-venture-for-omega-3-fatty-acids-from-natural-marine-algae-for-animal-nutrition.html
Food and Agriculture Organization, (2018, July 9). Is the planet approaching "peak fish"? Not so fast, study says. Retrieved from http://www.fao.org/news/story/en/item/1144274/icode/
Food and Agriculture Organization. (n.d.). FAO's role in aquaculture: Aquaculture development. Retrieved from http://www.fao.org/aquaculture/en/
Food and Drug Administration. (2019). Advice about eating fish: For women who are or might become pregnant, breastfeeding mothers, and young children. Retrieved from https://www.fda.gov/food/consumers/advice-about-eating-fish
Harvard School of Public Health. (2019). Fish: Friend or foe? Retrieved from
https://www.hsph.harvard.edu/nutritionsource/fish/
Harvey, A. C., Monica, F. S., Troianou, E., Carvalho, G. R., Taylor, M. I., Creer, S., . . . Glover, K. A. (2016). Plasticity in growth of farmed and wild Atlantic salmon: Is the increased growth rate of farmed salmon caused by evolutionary adaptations to the commercial diet? BMC Evolutionary Biology, 16. doi:http://dx.doi.org/10.1186/s12862-016-0841-7
Holt, M., Campbell, R. J., Nikitin, M. B. (2012). Congressional Research Service: Fukushima nuclear disaster. Retrieved from https://fas.org/sgp/crs/nuke/R41694.pdf
Karlsson, S., Diserud, O. H., Fiske, P., & Hindar, K. (2016). Widespread genetic introgression of escaped farmed Atlantic salmon in wild salmon populations, ICES Journal of Marine Science, 73, (10), 2488–2498. https://doi.org/10.1093/icesjms/fsw121
Kelly, B. C., Ikonomou, M. G., Higgs, D. A., Oakes, J. & Dubetz, C. (2008). Mercury and other trace elements in farmed and wild salmon from British Columbia. Environmental Toxicology and Chemistry 27(6).
Kelly, B. C., Ikonomou, M. G., Higgs, D. A., Oakes, J. & Dubetz, C. (2008). Mercury and other trace elements in farmed and wild salmon from British Columbia. Environmental Toxicology and Chemistry 27(6).
Leschin-Hoar. C. (2017, Feb 13). 90 Percent of fish we use for fishmeal could be used to feed humans instead. Retrieved from https://www.npr.org/sections/thesalt/2017/02/13/515057834/90-percent-of-fish-we-use-for-fishmeal-could-be-used-to-feed-humans-instead
Martinez-Porchas, M. & Martinez-Cordova, L. R. (2012). World aquaculture: Environmental impacts and troubleshooting alternatives. The Scientific World Journal 2012 #389623. Doi: 10.1100/2012/389623
Megdal, P.A., Craft, N.A. & Handelman, G.J. (2009). A simplified method to distinguish farmed (Salmo salar) from wild salmon: Fatty acid ratios versus astaxanthin chiral isomers. Lipids 44(6): 569–576. https://doi.org/10.1007/s11745-009-3294-6
Solberg, M. F., Skaala, Ø, Nilsen, F., & Glover, K. A. (2013). Does domestication cause changes in growth reaction norms? A study of farmed, wild and hybrid Atlantic salmon families exposed to environmental stress. PLoS One, 8(1) doi: http://dx.doi.org/10.1371/journal.pone.0054469
Sprague, M., Dick, J., & Tocher, D. (2016). Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006-2015. Nature Scientific Reports 6, 21892. doi: http://dx.doi.org/10.1038/srep21892
Washington State Department of Health. (n.d.-a). Contaminants in fish. Retrieved from https://www.doh.wa.gov/CommunityandEnvironment/Food/Fish/ContaminantsinFish
Washington State Department of Health. (n.d.-b). Farmed salmon vs. wild salmon. Retrieved from https://www.doh.wa.gov/CommunityandEnvironment/Food/Fish/FarmedSalmon
Washington State Department of Health. (n.d.-c). Health benefits of fish. Retrieved from
https://www.doh.wa.gov/CommunityandEnvironment/Food/Fish/HealthBenefits
Photo Credit:
US Environmental Protection Agency. (July 2010). Spawning male sockeye, Public Domain. Retrieved from https://commons.wikimedia.org/w/index.php?curid=51971558
