The Northeast Atlantic mackerel is a small fish with grey or greenish-blue scales and tigerlike black stripes from mouth to tail. Lacking a swim bladder—the gas-filled organ that helps most fish move up and down in the water—the mackerel would sink and die if it ever stopped. So it is always on the move, looking for plankton, crustaceans, and other small fish. It travels in shoals that can be more than 100 feet deep and 600 feet wide, and sometimes, when this great nomadic army catches a glimmer of light, it can resemble an underwater version of the northern lights.

In recent years, the mackerel’s unceasing motion and radically increased abundance have taken it farther north, to Greenland or Svalbard, which lies between Norway and the North Pole, and northwest, to Icelandic waters. And when the fish turned up, the Icelanders took advantage. By tradition, their nation had no claim to this fish, but starting in the mid-2000s, when the lucrative fish arrived in great numbers, they struck.

These fish are not like oil or diamonds or most other natural resources. They move. Most mackerel will start their life in the warmer spring months in Irish and British waters, but they migrate through seas belonging to the European Union, Norway, the Faroe Islands, recently Iceland, and sometimes Greenland, before returning south and east to spawn again. Throughout the annual migration cycle, they grow. A mackerel caught in Norwegian waters is bigger, fatter, and more valuable than those caught in the waters of the Faroe Islands or Iceland. And when the species moved farther north, it set in motion an international conflict about who gets to fish it.

Fishing rights are devised by geography, and by historical practice, and all the countries that fish mackerel meet annually to decide how much each gets. The negotiations that govern these rights are meant to benefit all countries involved while making sure that the resource is not depleted.

Collectively, they try to agree on how much each country should receive. If a country accepts a lower share, agreements allow its fishermen to go after mackerel when it’s fatter, within the borders of partner countries. But for more than 10 years, since the mackerel’s migration patterns started to change, these negotiations have failed to result in agreements between all nations. And if they cannot decide how to divide up the mackerel, the amounts fished will exceed what is considered biologically sustainable, even with new abundance.

A fisher stands on a pile of fish
A French fisherman sorts through a catch on board a trawler. (CHARLY TRIBALLEAU / AFP / GETTY)

If one country starts fishing more than the others have agreed to, they can’t do much about it. In the past, countries agreed on at least the principles that governed these divisions; now, with the waters around them changing, the rules for dividing resources have broken.

Representatives from mackerel-fishing nations met in November; again, they failed to reach a consensus. Although the disagreement had started more than 10 years ago, when Icelandic fishermen began trawling for mackerel, and the Faroe Islands subsequently unilaterally tripled their own quota, the puzzle became more complicated as the negotiation parties waited for Britain, one of the largest fishing nations in the region, to step further out of the European Union. With this move, the U.K. has become one more predator competing at the top of the food chain.

Every year, the International Council for the Exploration of the Sea releases an assessment of how populous a species is and how much of it can be fished. The assessment is the basis for negotiations between its member countries. Because the mackerel-fishing countries don’t all agree on the amounts they can fish, they now exceed what ICES recommends. In 2018, ICES recommended fishing 550,000 tons; the EU, Norway, and the Faroe Islands alone—leaving out Iceland, Russia, and Greenland—agreed to limit fishing to 800,000 tons. In the end, roughly 1 million tons were fished in the region.

There has been a lot of mackerel in recent years, but when the countries can’t agree on a share in good times, the stock can deplete quickly if circumstances change. Fifteen years ago, some of the same countries couldn’t decide how to distribute blue whiting, and that had devastating consequences. When the countries did agree in 2006, they divided more than 2 million tons of blue whiting among them. Just five years later, in 2011, less than 40,000 tons were left. Abundance in the oceans can be fleeting and, like the northern lights, unpredictable.


Even though Norway, Iceland, and the Faroes fish great amounts of mackerel, the fish is not, traditionally, beloved as food. The northern Norwegians used to believe that mackerel ate bodies lost at sea, which gave the fish its meat-like consistency. A Faroese chef once told me that freshly caught mackerel decays quickly because of its high fat content. Hence the fish’s typical presentation: smoked, pickled, canned.

In these Nordic countries, some people eat mackerel on bread with a tomato sauce, or smoked and used as a spread. Otherwise, they don’t eat it. Growing up in the Faroes, I remember my grandfather using mackerel as bait for cod. He would never eat mackerel. In Norway, mackerel has always been eaten in the South, but never in the North, where it is also considered bait.

In the late ’60s, though, the Norwegian fleet adopted refrigerated sea-water systems, which cool the fish onboard and make fresh mackerel more appealing. In the ’80s, Japan started buying Norwegian mackerel; since then, the price of the fish has tripled. In 2019, Norwegian mackerel sold for an average of $1.83 a kilo. (As a comparison, a kilo of herring fished in the North Sea sold for an average of $0.64.) Several shipowners, the ship association Pelagisk Forening, and fishermen all told me that mackerel now accounts for about 40 percent of their income.  

By 2006, when Icelandic fishermen who were trawling for herring started seeing mackerel in their nets, they recognized the fish’s potential. Páll Guðmundsson, the managing director at Huginn EHF, a fishing company based on an archipelago off Iceland’s south coast, sensed an opportunity. He emailed the Icelandic fisheries minister and the leader of the country’s Marine and Freshwater Research Institute, a government institution that provides scientific data about Icelandic waters. The unusual abundance of mackerel suggested that “they are worth fishing,” he wrote. “With the temperature of the sea becoming warmer, it could really be possible.”

What Páll wanted was a license to survey Icelandic waters. If Iceland wanted a piece of the species, it had to prove to the other countries that its waters contained mackerel.

The fishing officials, he told me, “didn’t even answer the email.” The following year, he called the institute with a new proposal: He would pay for the mackerel survey himself if the institute provided experts. This time, the request was granted. With a crew of 18 fishermen, and two biologists from the institute, Páll’s brother, Guðmundur Guðmundsson, captained their trawler, Huginn, to southern Icelandic waters to conduct their survey.

Gudmundsson brothers
The Gudmundsson brothers (Kári Bjarnason)

The numbers from the survey were not made public, but that year, 2007, the Guðmundsson brothers and other Icelandic fishermen, combined, fished 32,000 tons of mackerel in Icelandic waters, up from 4,200 in 2006. In 2008, their catch more than tripled, to 110,000 tons. Now everyone believed Páll and his captain brother, and Icelanders talked about seeing so much mackerel that the ocean looked like it was boiling with the fish. The Icelandic government was now ready to fight the other mackerel-fishing nations for the right to the species.  

Since 1999, the EU, Norway, Russia, and the Faroe Islands have been sharing the Northeast Atlantic mackerel stock. At first, they refused to recognize that Iceland had the right to mackerel at all. But in 2010, the evidence was clear: Mackerel had come to Iceland, and the other countries had to accept Iceland’s claim in order to control catches. Even after that concession, the traditional mackerel fishers thought that Iceland demanded too much of the share.  

Part of the problem for these countries was that Iceland had never fished mackerel before. “We’ve fished herring in Icelandic waters since 1870. And we never caught a mackerel,” Inge Halstensen, a Norwegian shipowner based in the town of Bekkjarvik, told me.

Halstensen, 75, has been leading the family company, K Halstensen, which his grandfather founded in 1897, since 1979. For years he has participated in transnational negotiations for different fish species—herring, blue whiting, mackerel.

According to Halstensen, Iceland has always been difficult to negotiate with. In 2000, a Norwegian delegation went to Iceland’s capital, Reykjavík, to negotiate a share of blue whiting. Norway’s chief negotiator, a role always fulfilled by a state official, was new at the job, and Iceland was hosting the negotiations. Halstensen said that the Icelandic diplomats were extraordinarily persuasive and, to put on a show for their guests, talked only about conservation and responsibility, which dazzled the Norwegian official. “We told him not to trust the Icelanders, because they will have a change of heart at the last moment,” Halstensen told me, laughing nostalgically.

Halstensen’s colleague, another shipowner in the Norwegian delegation, told the negotiator, “If they don’t turn, I’ll buy you a box of wine bottles. But if they turn, you will have to buy me a box.” Halstensen and his colleague, in the end, were right, and the negotiations fell apart. (Kristján Freyr Helgason, who is Iceland’s chief negotiator today, wasn’t surprised that the Norwegians were critical of Iceland’s negotiations. “Norway [and the Faroe Islands] are not going to be talking in favor of Iceland. I have to do that myself,” he told me.)

From 2014 to 2020, the EU, Norway, and the Faroe Islands agreed on a share between them and set aside 15.6 percent for Iceland, Russia, and Greenland to share. But in recent years, Iceland alone has fished enough mackerel to account for about 16.5 percent of the limit set by ICES. To Helgason, the percentage set aside by the three parties in the agreement for the rest was painfully inadequate. “It’s never going to be enough for the three [remaining] parties,” he told me.

If the mackerel now travels regularly to Icelandic waters, Halstensen, for one, concedes that Iceland’s share has to change. But he thinks that the country should accept a lower share than the Faroes and Norway, which have historical mackerel fisheries. He doubts, however, that Iceland ever would accept this. “They would tell us to get lost, and just fish anyway,” he told me.


Mackerel is an adaptable fish. Its ideal water temperature is 50 to 60 degrees Fahrenheit, but it has been found in waters as cold as 40 degrees and as warm as 68. Some scientists have attributed mackerel’s relatively sudden appearance in Iceland and Greenland to rising temperatures, as the oceans since 1970 have absorbed 93 percent of the heat from human-caused climate change. But although there is a consensus that mackerel has changed its migration pattern, scientists don’t agree about why that happened.

Dorothy Dankel, who is originally from Indiana, has lived in Norway since 2001 and works as a fisheries biologist at the University of Bergen. She’s interested in how humans and the environment interface: “When you talk about fish, you talk about politics, you talk about the economy, you talk about jobs,” she told me. Last year, she and a group of other scientists published a paper about the cascading complications of climate change in the governance of Arctic fisheries, what they call “the Melting Snowball Effect.” To her, climate change is obviously an important factor in the northern expansion of Northeast Atlantic mackerel. Mackerel itself might be resistant to slight changes in temperature, but it hunts plankton, which, because of a rise in sea temperature, has expanded and moved north over the past 40 years, accelerating from about 2000. The mackerel “wouldn’t be going to Iceland if there wasn’t food,” she told me. “I mean, the food is there. Why is the food there? It’s warmer.”

mackerel
(Modrow / laif / Redux)

Broadly speaking, climate scientists expect that warming oceans will change the distribution of fish. Climate models show that more fish than not should shift their migration patterns, and farther south, fish that have long preferred tropical waters are indeed moving northward. In Iceland, other fish—capelin, cod, and blue whiting—also appear to be on the move. Still, with fisheries, the signal of climate change isn’t always so clear: Human pressures are varied enough that climate cannot always be cast as a distinct culprit for the changing movements of a particular species.

"I want you to understand how complex this is,” Leif Nøttestad, the principal scientist for mackerel and some other pelagic fish at the Institute of Marine Research in Norway, told me.

Together with counterparts from other mackerel-fishing nations, the institute surveys the sea to provide data for ICES’s annual recommendation. Nøttestad is in charge of some of the pelagic-fish species, including mackerel and bluefin tuna; his office contains a poster of different tunas, two mackerel pillows from IKEA, and at least one fish-shaped pen. As I was listening and taking notes, he  flicked through different PowerPoints and talked about why the mackerel travels more northward than it used to.  

Nøttestad isn’t convinced that climate change was the main driver for mackerel’s northern migration or the population’s explosion. “There are great dynamics and variations in nature from one year to the next,” he explained. While the overall temperature of the North Atlantic has risen over several decades, the annual fluctuations have been great, and the area has cooled slightly in the past five years. He thinks the mackerel turned up in Iceland for other reasons; as the overall population grew, the fish could have been forced to expand into new areas to hunt, for instance. "There are very few species of fish in the world that inhabit such a big area. The mackerel has spread its risks quite broadly in time and space and would survive in most circumstances,” he said.

These uncertainties have to be factored into the annual ICES estimates of how much mackerel is in the sea and where. Though these numbers are based on science, they can have such powerful economic implications for fishermen in all participating countries that they are politically important too. The ICES recommendations have been disputed more intensively since 2019, when the council recommended decreasing mackerel fisheries from 1 million tons to about 600,000 tons just one year later.

That recommendation—and the implication that mackerel was being overfished—caused the Marine Stewardship Council to suspend the use of its blue sustainability label on all Northeast Atlantic mackerel. ICES later revised its recommendation to 770,000 tons, after immense pressure from governments, scientists, and fishermen associations. The international organization attributed the first recommendations to miscalculations and admitted in one report that “the degree of certainty/uncertainty of the advice needs to be better communicated.”

To Dankel, the numbers indicate that the way these countries govern fisheries doesn’t make sense. She thinks the primary purpose of the marine institutes’ surveys—given that the recommendation can be so variable—is to provide the political system with numbers for negotiations, rather than to put the stock’s conservation at the top of the agenda. ICES’s miscalculations made industry members more skeptical of the science behind the annual fishing recommendations, and Dankel thinks they showed that science has little idea exactly how many fish are in the sea. “It’s miscommunicating how much we don’t know about this,” she told me.

Nøttestad, too, thought that ICES’s stock estimation in 2019 was too low. He was among those who put pressure on the council to make a new recommendation. But rather than becoming skeptical of the science behind these estimations, he thinks that the institutes and the council should continue to strive to reduce that uncertainty in the outlook for the next year—even if, over the long term, climate change will cause a revolution in how fish in the area act.

"We can prophesy scenarios in 20, 50, or 100 years, but at the end of the day, the best we can do is to adapt to the situation right now," Nøttestad said. Norway’s chief fisheries negotiator, Ann Kristin Westberg, agrees. “It doesn’t matter if it’s climate change or not,” she told me. “You have to deal with it no matter what the driver is.”


I lived in the Faroe Islands in 2011, when the Faroese fisheries minister at the time, Jacob Vestergaard, a rather charismatic and impetuous member of the conservative People’s Party, decided to leave the mackerel agreement. Later, he chose to increase the Faroese share of herring. The tiny island group infuriated the grand European Union, which imposed a trade boycott on the Faroes. Faroese ships carrying herring and mackerel were banned from European docks; because the Faroe Islands are part of the Danish realm, and Denmark is part of the EU, the ships were effectively banned from parts of their own kingdom.

But Vestergaard became a national hero, especially for fishermen and shipowners, who were fishing more pelagic fish than ever. The Faroese political system is notoriously divided, with little cooperation between government and opposition, but suddenly everyone united behind the minister. Opposing him became political suicide. When the Faroe Islands next entered into a mackerel agreement with Norway and the EU, in 2014 (getting 13 percent of the share compared with 5 in the old agreement), that was also perceived as a national victory.

Since then, the EU, Norway, and the Faroes have been in disagreement with the other three mackerel-fishing countries, largely dividing the share among themselves and leaving Iceland, Greenland, and Russia out. Different countries lean on different arguments to justify increasing their share. Norway has a clear biological claim, as the mackerel spends a long time in Norwegian waters; Russia’s claim rests on historical rights—the stock is never in Russian waters, but the country has been fishing mackerel in the Northeast Atlantic for a long time, and was part of the coastal agreement in 1999. A country’s economic dependency on fisheries might also be used as an argument.

The three-party 2014 agreement was extended in 2018, and again in 2019. But it expired at the end of 2020. On November 25, when representatives from all mackerel countries in the region met, they realized that there was no basis for an agreement while Brexit negotiations were ongoing and decided to meet again at the beginning of 2021. On December 24, the U.K. and the EU signed an agreement on fisheries, which laid out a transition period of shared fisheries until 2026, when the U.K. will regain full control of its ocean. The mackerel-fishing nations of the Northeast Atlantic have not yet met for negotiations, and no agreement about any share of the fish is currently valid. Neither Norway nor the Faroe Islands have access to British waters, where they usually catch significant amounts of their quota.

The situation might become what Audun Maråk, the director of Fiskebåt, the largest shipowners’ association in Norway, anticipated when I met him in Bergen in January 2020. He is a regular member of the Norwegian negotiation delegation. It’s Fiskebåt’s members that are most furious with the Icelandic claims, but that wasn’t what primarily worried him when we met. Because of Brexit, he predicted total chaos in the negotiations over the next five years. And on January 12 of this year, he told a Norwegian fishery newspaper that if Norway lost access to British waters, it would have to increase the quota it fishes in its own waters. Vestergaard similarly highlighted to the Faroese Parliament late last year that access to British waters was essential to the agreement between the Faroe Islands, Norway, and the EU. As everyone now waits for Britain to show its hand, the scenario in which no agreement exists and every country fishes what it wants seems very possible again.

The Guðmundsson brothers of the Westman Islands don’t care too much about the politics of the transnational negotiations. That’s something the officials in the capital can take care of. The brothers are more concerned that their 6.6 percent of the Icelandic share doesn’t reflect the role they played in getting Iceland its mackerel. They feel that the Icelandic government should give them more of their country’s share for their early mackerel efforts. But as Captain Guðmundur, who is keen to reach an agreement with Norway, where he can catch mackerel that have a higher fat content and are more valuable, puts it: “After you bake the cake, everyone wants a piece.”

At home on the island, Páll is running the business. He disagrees with his brother and does not think Iceland should consent to anything that would give them less fish than they currently have. And in the end, it perhaps doesn’t matter what the brothers or any chief negotiator in Iceland wants right now. The sentiment, at least among Norwegians, is that Iceland’s demands so far have been unrealistically high. Besides, everyone is more concerned with Britain than Iceland at the moment.

Back in Bekkjarvik, Norway, Halstensen doubts that the fishing nations will reach any unanimous agreement over mackerel in the next 10 years. “Iceland will not be satisfied until they get more than they think is rightfully theirs,” he told me, and pointed out that the countries also have problems agreeing when it comes to other species. An agreement would “take a lot of statesmanship,” he said.

When I visited him in his office, Halstensen was on the phone, talking about the flowers his company was buying for Knester, the other big fishing company in the village, which had just bought a new ship. Everyone—even local competitors—is excited when Bekkjarvík adds a ship to its fleet. As he prepared to go to Knester’s reception, his brother, a clinical-science professor based in Bergen, was going through some paperwork for the company. Halstensen’s son Christian, who leads parts of the family enterprise, and two grandchildren stopped by. “They come home from school and ask, ‘Grandfather, are you fishing sustainably?’” he said. “All these things have changed a lot over the last years.”

Mackerel has thrived in the past several years, and the stock does not seem to have been depleted yet, even though countries have fished too much. As none of the countries has an agreement for next year, the scene for conflict is set anew. And they might not be as lucky with their fishing’s impact on the resource in the future. Perhaps Nøttestad will have rightly worried that no one could agree when there was so much mackerel. He is afraid that they won’t reach consensus until nothing is left to fish, and mackerel has lost its economic importance. “This is food for millions that we must manage sustainably for the next generations,” he said.