Farmed fish feed fears flummox

Is farmed fish safe to eat? A European investigation into salmon feed looks to find out

Fish farm

Photo: Johan Wildhagen, © Norwegian Seafood Council, by permission
A Norwegian fish farm cage.

M. Michael Brady
Asker, Norway

From the Viking Age on, Norwegians have plied and harvested the seas. Fish export has long begotten income, perchance from the year 875, when, as an Icelandic Saga reports, a Viking chieftain sailed with a cargo of dried cod from the Lofoten Islands to England to trade for clothing and other necessities. Even then, cod was commonplace in the coastal cultures of the countries of the north. But with time, the more modest catch of Atlantic salmon came to set Norway apart.

Topography determined that distinction. The rivers of the Scandinavian watershed flow through Norway and empty into the Atlantic Ocean. Together they make up the world’s largest spawning ground for wild Atlantic salmon. That has triggered a social phenomenon, as each year tens of thousands of native and foreign recreational anglers fish these salmon rivers.

Yet for elusive reasons, sea fishing for salmon declined in the late 1960s and early 1970s. The ensuing depression of the economies of coastal communities that depended on it triggered a shift to salmon farming. From a few salmon farms along the coast in the mid 1970s, salmon farming developed dramatically. In the nine counties along Norway’s west coast, there now are more than 1,250 salmon farms. Farmed salmon has replaced wild salmon in markets, and Norway has become the world’s largest producer of it.

That event in Norway is part of a global trend. Aquaculture, the farming of fish and other sorts of seafood, now supplies more than half of all seafood produced for human consumption. Around the world, most salmon sold in fish shops and supermarkets is of the farmed sort. There’s historical precedence for that statistic. Fish farming began in China circa 2,500 BCE. It has evolved, as has farming, since the First Agricultural Revolution circa 10,000 BCE. Now it’s at a stage similar to that of the Second Agricultural Revolution of the 17th through 19th centuries, marked by an unrivaled rise in farm productivity. But nothing happens without consequence, and aquaculture, like agriculture, has disadvantages as well as advantages. So as with agriculture, there’s much critique of aquaculture.

Farmed fish

Photo: Tom Haga, © Norwegian Seafood Council, by permission
Salmon as the consumer most often sees it.

Farming salmon has a limiting disadvantage due to the nature of the fish. Salmon are carnivorous; they eat other fish. So farmed salmon are fed fishmeal. The fishmeal is usually transported by ships. Fish oil present in fishmeal can react with oxygen in the atmosphere and generate heat that causes it to catch fire. So antioxidants are mandatory additives to fishmeal to prevent fire in transport and storage. The most used antioxidant is ethoxyquin, a synthetic substance developed in the 1950s by the Monsanto agrochemical company and now used in the fishmeal pellets fed to farmed salmon.

Ethoxyquin, or EQ as it’s often abbreviated, is at the center of the ongoing public discussion of salmon farming. The principal question is whether EQ in fish feed can be transferred to the edible parts of the fish and thereby affect food safety. In Norway, there’s been a governmental white paper and a doctoral dissertation (both in English) that both report measurable transfer from feed to edible fish.

Internationally, the authorization of EQ as feed additive has been suspended in the European Union (EU) and members of the European Economic Area (EEA) not in the EU (including Norway), pending a scientific review to be completed by the end of December 2020. And an early April 2018 edition of Morgenbladet, Norway’s cultural weekly newspaper, had a front page, eight-page feature on EQ.

EQ has been an additive to fish feed at least since 1971, when its use was reported in a public information leaflet published in Scotland, another salmon-farming country. So after more than four decades of EQ use, the ongoing EU/EEA scientific review may find that its use is not a food-safety concern. But then it may not so find, which would lead to a ban. So the search is now on for an alternative to EQ in fish feed. Three antioxidants are now being considered, the tocopherols (Vitamin E compounds), rosemary extracts, and the synthetic substance Butylated hydroxytoluene (BHT).

Eliminating fishmeal in farmed fish feed might be another way to go. As reported by the National Geographic this past February, Protix, a company based in Dongen, the Netherlands, has developed and successfully tested a farmed fish feed based on insects it breeds for animal feed.

Further reading:

• “Wild and farmed salmon in Norway: A review” by Y. Liu, J.O. Olaussen, and A. Skonhoft, Marine Policy Vol. 35, May 2011.

• “Seafood from Norway,” Norwegian Seafood Council website (English):

• “As Wild Salmon Decline, Norway Pressures Its Giant Fish Farms” by S. Castle, The New York Times, Nov. 6, 2017.

• “What undesirable substances are transferred from the feed to the fillet?” Havforskningsinstituttet (Institute of Marine Research) white paper (English), Oct. 1, 2015:

• “Ethoxyquin i fiskefôr” (Ethoxyquin in fish meal) Norwegian Food Safety Authority overview, Jan. 24, 2017 (Norwegian).

• “Det vi ikke vet om laksen” (What we don’t know about salmon) by S. Sætre and K. Østli, Morgenbladet, April 6-12, 2018 (Norwegian).

• “Ethoxyquin: An Antioxidant Used in Animal Feed” by A. Blaszczyk, A. Augustyniak, and J. Skolimowski, International Journal of Food Science, April 30, 2013.

Toxicokinetics and toxicodynamics of dietary ethoxyquin in Atlantic salmon (Salmo salar, L.), Doctorate dissertation by V.J.B. Bohne, University of Bergen, 2007.

• “Nøkkeltall fra norsk havbruksnæring” (Key figures from aquaculture), Directorate of Fisheries annual publication (Norwegian).

• “Implementing regulation (EU) 2017/962: Suspending the authorisation of ehyoxyquin as a feed additive for all animal species and categories,” Official Journal of the European Union, June 7, 2017, PDFs in all EU languages, and “Suspansjon av ethoxyquin som fôrtilsetningsstoff,”, June 16, 2017, [statement of Norway’s compliance (Norwegian)].

• “Fish Meal” by M.L. Windsor, Aberdeen, Scotland, 1971, Torry Research Station.

Fisheries and Aquaculture Statistics, Food and Agriculture Organization (FAO) of the UN, trilingual yearbook (English, French, Spanish) 2015 edition published Nov. 10, 2017:

SSPO briefing on Ethoxyquin use, Scottish Salmon Producers Organisation, May 12, 2017.

• “Why Salmon Eating Insects Instead of Fish Is Better for Environment” by H. Brady, National Geographic, Feb. 5, 2018:

M. Michael Brady was educated as a scientist and, with time, turned to writing and translating.

This article originally appeared in the June 29, 2018, issue of The Norwegian American. To subscribe, visit SUBSCRIBE or call us at (206) 784-4617.

You may also like...