The challenges arising from climate change are global and require international cooperation if they are to be adequately addressed. But are existing international institutions and agreements well suited to overcome the stresses that climate change might provoke? The case study of the Northeast Atlantic mackerel fishery provides a cautionary tale.
For a decade beginning in 1999, the member states of an organization called the Northeast Atlantic Fisheries Commission (NEAFC) worked together to negotiate equitable shares in the mackerel fishery. These members—including the European Union (EU), Denmark (also negotiating for Greenland and the Faroe Islands), Norway, Russia, and the United Kingdom (separately since Brexit)—managed to find bargaining solutions that satisfied each of them.
But in the early 2000s, as the seas warmed, mackerel began moving northward toward Iceland in search of colder waters, and Reykjavik wanted to enter the agreement and receive its fair share of the allocation. In 2010, Iceland became a member of the NEAFC, but the organization has since been unable to negotiate an acceptable allocation of the fish, leading to what has been called a “mackerel war.”1 The consequence has been that overfishing has become the new norm; the United Kingdom’s Marine Conservation Society announced in early 2023 that Northeast Atlantic mackerel populations were “at risk” and the fish was no longer a sustainable seafood (see figure 1).
So, why did the agreement break down? We examine the devolution of mackerel cooperation by first looking at how climate change is affecting the spatial distribution of the fish. We then trace the history of the mackerel agreement and how negotiations are conducted. Finally, we seek to understand what has more recently made a bargaining solution so evasive. We find that the rising uncertainty about the future location of mackerel has transformed the underlying bargaining environment. When the future is uncertain, agents may act as if the future doesn’t really exist, leading to a scramble for resources today.
Fish on the Move
The planet’s oceans have absorbed more than 90 percent of the heat from anthropogenic climate change, and marine fish and other animals have already shifted poleward and into new territory at a rate averaging about 40 miles (60 kilometers) per decade. These shifts have occurred in part because marine species tolerate a relatively narrow range of temperatures. The large number of species on the move suggests that the mackerel case is an early example of international conflicts over fisheries and resources that are likely to become more widespread under a changing climate. 2
The geographic shift of Northeast Atlantic mackerel (Scomber scombrus) became particularly apparent in 2007 when the species appeared in large numbers near Iceland, rather than staying concentrated closer to Britain and Norway as in previous years. Mackerel then continued to move further north and west, including into the waters around southern Greenland, for reasons that have been linked to warming temperatures, prey, and population abundance.
Prior to the northern migration, Icelandic fishermen did not catch mackerel in any great numbers. With other types of fish reasonably plentiful within their country’s territorial waters, Icelanders did not need to stray far to earn a decent living. On the contrary, Iceland was on the receiving end of invading fishing fleets from other countries, perhaps most infamously during the various “Cod Wars” that pitted Reykjavik against London from the early 1960s to mid-1970s.3 Prior to the wars, during which the Royal Navy was sometimes deployed to defend British fishermen, London had refused to accept Iceland’s expansion of its territorial waters. By the end of 1976, London acquiesced to Iceland’s actions, partly because the United States expressed concerns that the conflict could erode the North Atlantic Treaty Organization. At the same time, more maritime nations were also expanding their exclusive economic zones (EEZs) out to a 200-mile limit, bolstering Iceland’s position.
Yet, the 200-mile limit did not solve the problem of which states control the fisheries. After all, most fish move across borders—even more so with climate change and warming ocean waters. Mackerel are among these fish but hardly alone, meaning that international fisheries cooperation will increasingly need to reckon with the problem of who gets to catch what. Unfortunately, international maritime law may be of limited use as nations navigate these waters.
The NEAFC Agreement
One of the first books in the history of international law is Hugo Grotius’s Mare Liberum (1609), which famously advocated for “freedom of the seas.” Grotius made the novel argument that the oceans represent “international” territory and that every state is free to make use of them. This extended to fisheries, whose bounty he believed to be so extensive that mankind could never exhaust it. Within two centuries, this general belief about the size of the world’s fisheries was gradually undermined, as species depletion—including in the whale fishery—raised the effort needed to achieve a catch.
In 1882, a group of European nations signed the North Sea Fisheries Convention in an effort to defuse fishery-related conflicts on the “open” sea. Under this convention, the countries were allotted exclusive fishing zones out to 3 nautical miles and were required to display identifying national markings on their fishing boats and gear. While no particular efforts were made to assess fish stocks at that time, hindsight at least reveals that environmental concerns were of growing importance, as a German delegation to a different fisheries conference proposed the adoption of measures “for the protection of young fish.”4
World War I and World War II dampened further efforts at reaching fishery agreements, but these were soon taken up again during the immediate postwar era. In November 1945, the United Kingdom was already proposing that international measures be taken to preserve fish stocks, at first focusing on the mesh size of nets and minimum landing-size provisions. Regular meetings were held among coastal states, and 1958 saw the first UN Conference on the Law of the Sea (UNCLOS). Regional fishery agreements grew out of the UNCLOS process, and NEAFC began operations in London in 1963.
During its early years, NEAFC continued to focus on regulating fisheries through net mesh rules and landing sizes, but by the 1970s this evolved into the development of allocation schemes for particular fisheries. Each nation’s fishery would receive a total allowable catch quantity, which was politically determined and generally reflected the interests of fishermen rather than conservationists. During the 1990s and early 2000s, however, growing concerns about the sustainability of global fisheries led nations to reconsider how allocation decisions should be made. With specific respect to mackerel, in 2008 a group of coastal states (the EU, Norway, and the Faroe Islands negotiating independently) requested that a scientific body, the International Council for the Exploration of the Seas (ICES), whose origin dates back to 1902, provide input regarding harvesting levels. ICES recommendations were based on the concept of maximum sustainable yield (MSY), or the amount of fish that could be withdrawn from the stock to help it produce the greatest harvest over the long term.
It is perhaps worthwhile to emphasize a point that is often lost in discussions of fishery conservation, namely that MSY does not necessarily equal the most economically efficient catch. Importantly, a monopolist fisherman might catch below the MSY to reduce costs and maximize profit. (No matter the sector, monopolists generally produce less output than markets would demand at competitive prices; as an example, consider Saudi Arabia’s oil production decisions.) Conversely, since many fisheries are highly competitive, there is pressure from the industry to catch more than the MSY so that each boat nets enough fish to sustain its annual operations. This tension between short-term economic pressures and long-term ecological concerns explains why international agreements are necessary to avoid a tragedy of the commons and maintain fisheries in cases where many competitors have open access to the available stocks.
In 2008, the core coastal states with active mackerel fisheries adopted an allocation scheme that accounted for scientific advice. But this allocation did not account for the species’ geographic shift toward Iceland. When mackerel appeared in Iceland’s coastal waters, the fishermen there quickly took advantage of the new situation. Between 2006 and 2010, the amount of mackerel caught by Icelandic fishermen increased by nearly thirty times.
In recognition of these developments, beginning in 2010, Iceland joined its European neighbors in seeking to negotiate an acceptable quota arrangement. Nearly fifteen years later, that process has yet to yield an agreement.
Bargaining Failures Over Mackerel
When mackerel moved northward to Iceland, Reykjavik naturally assumed that the existing quota allocations had become null and void. After all, it made no sense for, say, Norway to receive the same amount of fish now as it had when the mackerel were more heavily concentrated off its shores. But the other coastal states countered that the historic allocations should be respected and that Iceland would be allocated some share of the overall amount—a much smaller share than it would have claimed unilaterally.
The reason for this intransigence can be boiled down to uncertainty over the future evolution of the fish stock, particularly in terms of its spatial distribution. In an environment in which the location of the fish and the parties’ catches will always remain the same, the existing bargain over the allocation of the mackerel is likely to be maintained. But when an exogenous environmental shock causes the fish to move into one country’s EEZ, that country does not know how long and how many fish will linger in its waters. In this scenario, that country might be forgiven for exploiting more than its previous share would have permitted. However, once the stock becomes overfished and drops to low abundance, fisheries managers can find it hard to recover abundance—or the stock might never recover at all.
Therefore, uncertainty over the future can make it difficult, if not impossible, to achieve a new bargaining solution. The mackerel case does not represent a tragedy of the commons so much as a tragedy of uncertainty.
Implications for International Mackerel Cooperation
Noted climate activist Greta Thunberg has repeatedly asserted that politicians should “listen to the scientists” when it comes to climate change. But whatever the merits of that advice, scientists don’t and likely won’t have all the answers when it comes to the precise trajectories of individual ecosystems. Under conditions of future uncertainty, political conversations need to be resilient and adaptable across a range of potential futures.
Future uncertainty shrinks our time horizons, causing us to focus more narrowly on the near term. In the context of fisheries, this can lead to overexploitation because the ever-present incentives to catch today are no longer mitigated by a voice saying “preserve for tomorrow” when it is unclear what tomorrow holds. In the context of climate change, this uncertainty arises in part because of a major disconnect between the timescales of modern climate projections (a half century or more) and the timescales needed to make decisions (years to a decade or two). An area of active study with promise for reducing this uncertainty is potential new climate projections focused on upcoming years and decades.
Another challenge related to uncertainty about how ecosystems may evolve is how to extend the so-called shadow of the future—when players cooperate more now because they expect to have to repeatedly interact with other players over time.
So, what should NEAFC do to promote a new bargain regarding mackerel? First, any bargaining solution must leave all parties better off than they are without one. In that context, it is important to recognize that no party really wants to exhaust the fishery today; most fishermen want to leave some catch for their children. One way to smooth production over time would be to impose a windfall tax on the fishery when the catch is above some line, like a five-year moving average. For example, some European states imposed windfall taxes on highly profitable energy companies during the energy crisis of 2022. That tax could then be directed to a permanent fund for future generations, as Alaska has done with its oil.
Other solutions could be considered. NEAFC could propose auctioning quotas off, but smaller states would likely object that they are at a disadvantage when it comes to paying for the right to fish. It could also consider bundling species agreements, but it is probably a bad idea to bundle agreements that work with those that don’t. And, as noted before, these solutions are not inter-temporal as they should be. If the mackerel are to have not just a present but a future, negotiations must find a way to extend the time horizons of the fishermen.
Lessons for Climate Cooperation
The NEAFC is just one example of an international regime that was unprepared for exogenous environmental shocks, and there are many more such agreements. For example, the Indus Water Treaty, which governs cooperation between India and Pakistan on the water in the Indus River, is one of the major water-sharing agreements under pressure from climate change and rising consumption. Some environmental shocks change the very borders on which resource rights are based: small island states in the Pacific, such as Kiribati and Tuvalu, are concerned not only about fish moving to cooler waters but also about sea level rise that will flood their remote islands, thus reducing the size of the areas where they hold fishing rights. This has implications, for instance, for the Nauru Agreement, which regulates tuna fishing.
What makes the mackerel story so compelling is that, in many respects, it should represent an easy case for cooperation. The usual causes of bargaining breakdown, including asymmetric information and commitment failures, do not seem relevant here. That’s because NEAFC members have interacted with one another for many years; most members are military allies and, at least until Russia’s invasion of Ukraine, had reasonably cordial relations with Moscow. The majority of members are wealthy democracies with strong welfare states and thus have the ability to compensate losers from international agreements. And, with the advent of new technologies such as AIS tracking (an electronic signal that most fishing vessels broadcast), the members can increasingly monitor the activity of each other’s fishing boats. They can even act to enforce their agreements by, for example, turning away from nearby ports any boats that are cheating on the allocation scheme. In addition, an agreement can be in the long-run interest of fishermen to the extent that it helps preserve a healthy stock, ensuring that the hefty investments made in boats and gear today will be paid off with fish caught tomorrow.
The failure to reach an agreement in the mackerel case demonstrates that even wealthy democracies with largely friendly relations can struggle to cooperate in the face of climate-related stress. (Another such example is the difficulties that the U.S. states of the Colorado River Basin are having agreeing on a durable solution to manage their dwindling water resources.)
The tragedy of uncertainty present in the mackerel case is also relevant for negotiations on the exploitation of other resources whose future production is threatened either by exhaustion or by future environment- and climate-related restrictions. While distant-future projections are important, forecasts focused on upcoming years and decades are a scientific priority to match the timescales of human decisionmaking. Major producers of oil and gas—including self-professed climate leaders Canada and Norway—have so far been unwilling to seriously restrict the production of their hydrocarbon resources, preferring to develop what they can while they can. Because climate change makes the future uncertain, actors are encouraged to act in unsustainable ways that can make agreements even more difficult to achieve and the future even more uncertain.
Acknowledgments
The authors wish to thank Alisa Laufer, Nirina Randrianarisoa, and Adi Tantravahi for their research assistance and the many fishery experts who helped the authors understand the mackerel case. Research for this article was supported by a grant from the Department of Defense/Minerva Research Initiative. The views expressed are those of the authors alone.
Notes
1 For historical background, see Bjornar Dahl Hotvedt, “The Problem of Sharing a Common Stock: An Analysis of the Mackerel Conflict in the North East Atlantic” (master’s thesis, Norwegian College of Fisheries Science, 2010); and Jessica Spijkers and Wiebren Boonstra, “Environmental Change and Social Conflict: The Northeast Mackerel Dispute,” Regional Environmental Change 17 (2017): 1,835–1,851.
2 For more detail, see Malin Pinsky et al., “Preparing Ocean Governance for Species on the Move,” Science 360, no. 6394 (June 15, 2018): 1,189–1,191.
3 Sverrir Steinsson, “The Cod Wars: A Re-analysis,” European Security 25, no. 2 (2016): 256–275.
4 Arild Underdal, The Politics of International Fisheries Management: The Case of the Northeast Atlantic (Oslo: Universitetsforlaget, 1980): 48.
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