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tiny crustacea seen under a microscope
Calanus finmarchicus is food for cod, herring, basking sharks and right whales. But the booming omega-3 pill and fish-farming industries also want it. Photograph: Portland Press Herald/Getty
Calanus finmarchicus is food for cod, herring, basking sharks and right whales. But the booming omega-3 pill and fish-farming industries also want it. Photograph: Portland Press Herald/Getty

Cutting the food chain? The controversial plan to turn zooplankton into fish oil

This article is more than 2 years old

A budding industry that aims to catch zooplankton for health supplements and fish food has scientists fearing that its effects on marine ecosystems could be devastating

‘It’s mind-boggling’: the hidden cost of our obsession with fish oil pills

A few times a day, off the Faroe Islands’ coast, the crew of the Jákup Sverri marine survey ship test the water, measuring its salinity, temperature and oxygen at different sea depths. But they also look for something else.

Durita Sørensen, a laboratory technician, holds up the contents of a special net to demonstrate. If the water is greenish, it contains a lot of phytoplankton, the plants at the base of the oceanic food chain. But if it is red or brown, as in Sørensen’s net, the haul is one rung higher up the ladder: zooplankton. “This is calanus, or Calanus finmarchicus,” she says, indicating the tiny red creatures. “This is what they are interested in making fish oil [from] as a food supplement for humans.”

Zooplankton is a crucial part of the Atlantic Ocean ecosystem. And calanus – known as Reyðæti in Faroese or “red plankton” – is one of the most important and populous varieties. In 2020, the Faroese fisheries ministry gave five companies the right to fish for up to 25,000 tonnes of it each.

There is no factory yet on the Faroe Islands for processing the tiny red creatures into fish oil, but entrepreneurs are hoping it will soon become big business, supplying not only the apparently insatiable demand for omega-3 health supplements across the western world, but potentially for use in the even vaster fish-farming industry.

Faroese entrepreneurs hope to use the ‘red plankton’ to cash in on the boom in health-food supplements. Photograph: Regin Winther Poulsen

Zooplankton fishing is already happening in Norway, where a company called Zooca, which has been harvesting red plankton for some years, received a commercial quota in 2020. The Norwegian Institute of Marine Research says the harvest is well within sustainable limits.

But many in the fishing industry are unhappy about the idea of sucking up zooplankton. Red plankton is the main food of many hugely valuable fish stocks – including mackerel and herring – and is vital for the juvenile growth of a species that is a mainstay of the Norwegian and Faroese industrial fleets: cod.

Some scientists, meanwhile, warn that we have no idea what removing zooplankton from the oceanic food chain will do. “It’s a drop in the bucket right now,” says Peter Wiebe, scientist emeritus at the Woods Hole Oceanographic Institution in Massachusetts, of the current zooplankton harvest. “But what they have in mind is not a drop in the bucket.”


Zooplankton are tiny animals. They are copepods, or small crustaceans, each about the size of a rice grain. Zooplankton spend their summers in the sunny upper layers of the ocean, where they feed on phytoplankton, a plant that depends on photosynthesis.

During the winter, however, the zooplankton go into hibernation. They slowly sink down into the deeper layers of the ocean and, lacking the capability to swim, they then float with the current. Around the Faroe Islands, that means travelling south-east before being pushed up through the narrow Faroe Bank channel and into deeper, colder oceans, where it is estimated that 90% of them die.

This gave Eilif Gaard an idea. In his office, the head of the Faroese Marine Institute (Famri) holds up a box full of dark red capsules: omega-3 oil, made from red plankton. Zooca, the producer, says that its zooplankton oil is superior to conventional omega-3 oil, claiming in a 2019 paper that the zooplankton can counteract “insulin resistance and other obesity-induced metabolic disorders and exhibit a potent anti-inflammatory effect.”

Zooca says the demand for omega-3 has caused many species to become overfished, and claims zooplankton is a sustainable alternative.

Gaard wants a cut of this growing market for the Faroes. A marine biologist by training, as director of Famri he is more used to telling the fishing crews to catch less. But he proposed using the Faroe Bank channel to catch plankton that might otherwise die upon entering deeper open sea.

“We have this channel where the current flows through, which gives us a special opportunity,” he says. “By doing our fishing in the channel and only during winter, we aren’t affecting ecosystems.”

He admits not enough is known about the species after it leaves the continental shelf around the islands. Nevertheless, he recommended setting the zooplankton fishing quota at 125,000 tonnes, which he says is about 1.2% of the total mass of calanus that flows through the area.

One of the fishers who received a licence is Jógvan í Skorini. The former mayor of Eiði, a village of about 700 people, Skorini now works as a schoolteacher but always dreamed of fishing. In 2017, he got a call from his friend Heini Niclasen, who had just learned about the fledgling zooplankton industry.

Excited, the two friends flew to Norway, where they visited Calanus, the company that would later become Zooca, and left clutching a vital piece of paper. “We made a contract for exporting the potential harvest to them, and we get knowhow from them,” Skorini says.

Back in the Faroes, Skorini partnered with his uncle, one of the biggest shipowners in the islands, who also applied for a quota and rented a boat to Skorini to haul in their collective 50,000-tonne catch. With a price per kilo of about $1.50 (£1.10), zooplankton could become a $100m business for the Faroe Islands and its 50,000 inhabitants.

Harvesting plankton in the Faroes is easier said than done, however. The Faroe Bank channel is an undersea gorge about 50 miles (75km) south-west of the islands where cold water rushes through at an immense pressure of 2.2m cubic metres a second – twice the force of all the rivers in the world combined.

Skorini’s first trawl net was torn to pieces in the current. They are working to develop a new, specially adapted system that covers the fine mesh net under a wider outer net designed to withstand the water’s destructive power.

Skorini and his partners are learning from Zooca, which was started in 2002 by Kurt Tande, then a professor at the University of Tromsø in Norway. What began as a research company looking into the possible benefits of zooplankton omega-3 has since become a thriving business, employing about 100 people, selling its fish oil in Europe and North America, with a revenue of $9.2m last year. In August, the then Norwegian prime minister, Erna Solberg, visited Zooca’s newly built factory in Sortland.

Durita Sørensen extracts red plankton from the net. The force of the water around the Faroes can destroy the fine nets needed to catch the tiny creatures. Photograph: Regin Winther Poulsen

But other sectors of Norway’s fishing industry are concerned. Tom Vegar Kiil, head of Norges Kystfiskarlag, the association for Norwegian coastal fisheries, is one of the highest-profile opponents of zooplankton trawling. The Norwegian quota is 254,000 tonnes but, unlike in the Faroes, fishing for it is permitted all year – and in the warmer, upper layers of the sea, where Kiil is concerned that Zooca is catching larvae and juvenile fish in its nets.

“We haven’t been good enough at taking care of our stocks,” Kiil says, referring to Norway’s loss last year of its Marine Stewardship Council’s sustainability label on cod fished near the coast. The idea of fishing one of juvenile cod’s most important foods strikes him as shortsighted.

Kiil is also worried that the fish-farming industry will get involved. He fears that once they begin to use zooplankton for aquaculture they will start to demand even higher quotas – particularly for shrimp and salmon farming.

Wiebe, an expert on the ecology of zooplankton, says there is a growing appetite for these kinds of fisheries in the so-called mesopelagic zone – the layer in the sea 200 to 1,000 metres below the surface. “There’s a lot of interest in fishing that part of the ocean, to capture stuff for aquaculture, to use it for feed for agriculture. That has a lot of ramifications,” he says.

Others fishery associations have criticised the zooplankton trawlers for operating in spawning grounds during summer. And last year, Geir Jørgensen, a municipal politician in Nordland, led one of Norway’s regional councils to call on the national government to halt the trawling for plankton off the coast.

A basking shark feeding on copepod off the Inner Hebrides, Scotland. Large-scale fishing for zooplankton may harm the entire marine food chain. Photograph: Alex Mustard/NPL/Alamy

The marine biologists at Norway’s Marine Research Institute disagree with those who want the plankton fisheries curbed. Cecilie Thorsen Broms, the institute’s head of research, says the current fisheries take only a fraction of the allocated quota of 254,000 tonnes.

She says Zooca, which is still the only company fishing for red plankton, must test each haul for bycatch and that the numbers are far from frightening. “Our estimate has shown that the amount of bycatch is very small, so it will not affect the fish population,” she says.

But Wiebe is not convinced. Part of a working group at the International Council for the Exploration of the Sea that looks at the ecology of zooplankton, he thinks that what starts small now will only grow.

“They have in mind getting the technology to the place where they can actually go out and really exploit it,” he says of the budding zooplankton industry. “And I think, without the kind of studies that are needed to understand the dynamics of the populations there, we do that foolhardily.”

Zooplankton is a key part of the food chain, he points out, for fish as well as seabirds. “A lot of the big predators in the ocean swim down into the mesopelagic daily to feed. And so if you start harvesting that mesopelagic regime, you may well be doing damage to a different kind of commercial fishery.”

The chief executive of Zooca, Siv-Katrin Ramskjell, is not backing down. “We harvest way less than 0.01% of the quota that the Marine Research Institute thinks is sustainable,” she says.

Ramskjell argues that although bycatch was an early challenge, they have developed new technologies to minimise it and, far from reducing their catch of zooplankton, they plan to rapidly expand. “Today we only fish around 1,000 tonnes yearly, but the goal is to fish 10 times more – or around 10,000 tonnes in five years,” she says.

It is the prospect of that exponential growth that makes Javier Lopez, campaign director at the conservation group Oceana, fearful. “For us, this is an example of the greed of the human being to exploit and exploit,” he says. “It is true that maybe, to the extension that it is done right now, [zooplankton fishing] is not having an ecological effect – [but] we should not create any dependence on these kinds of resources.”

More on this story

More on this story

  • Revealed: many common omega-3 fish oil supplements are ‘rancid’

  • ‘It’s mind-boggling’: the hidden cost of our obsession with fish oil pills

  • Licence to krill: the destructive demand for a ‘better’ fish oil

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