As the North Atlantic Ocean Changes, Fisheries Management Must Evolve

North Atlantic swordfish are top predators that have adapted to hunting squid and other prey in deep waters. The species is priced commercially, with catch worth as much as US$10 million per year in Canada and at least US$10.6 million in the United States, and is popular among sport fishermen as well.

This combined heavy fishing pressure led to the overfishing of North Atlantic swordfish in the 1990s. The stock has recovered but could quickly decline again unless the International Commission for the Conservation of Atlantic Tunas (ICCAT) changes how it manages the species.

At its 11–18 November annual meeting in Limassol, Cyprus, ICCAT should take the opportunity to adopt a long-term, precautionary harvest strategy – known as a management procedure – which science shows should keep swordfish fisheries sustainable for the foreseeable future.  

Management procedures (MPs), help fisheries managers set catch limits and other rules for several years or decades – reducing the need for contentious annual negotiations.  With harvest strategies, managers use science to agree in advance on how fishing levels will fluctuate – if at all – based on the status of a fish population. ICCAT had a chance to adopt a harvest strategy for North Atlantic swordfish in 2023 but failed to do so.

Before adopting an MP, scientists test different options through a process called management strategy evaluation (MSE), which simulates fishing activities and environmental conditions to evaluate whether each potential rule would meet managers’ objectives. This is akin to airline pilots using simulations and models to learn how to approach mountains in windy conditions or land in the rain on a short runway. In fisheries, MSE can include incorporating climate science to improve fish populations’ resilience to expected changes.

ICCAT has completed its MSE for North Atlantic swordfish – an integral step to developing an MP. The Commission has adopted two other MPs, but this would be the first that has been explicitly tested for resilience to climate change. In recent years, Canadian scientists noted shifts in the distribution of Atlantic swordfish, seeing higher numbers of large fish in waters farther north than usual.

On the other side of the planet, the Indian Ocean Tuna Commission this year adopted the first MP for a swordfish fishery, proving that it’s beneficial to move beyond tuna species and into all stocks under a regional fisheries management organization’s purview. Now it is on ICCAT to do its part and advance swordfish management in the Atlantic.

Scaling climate-related action needed to advance Atlantic fisheries management

At its meeting in Cyprus, ICCAT should also adopt a proposed climate change action plan, which includes MSE development for more species the Commission oversees. Given the on-the-water changes already happening, the Commission should have a system in place to ensure fisheries managers are making decisions based on the latest science. The climate change action plan presents ICCAT with additional opportunities to scale-up management procedure development, including by incorporating climate tests into MSEs to ensure the best possible management plans for each species.

Managers should allocate additional resources and capacity to this effort, such as by expanding technical MSE expertise and adding more species to the existing harvest strategies roadmap – including Atlantic blue sharks, South Atlantic swordfish, and South Atlantic albacore tuna.

MSE-based harvest strategies are the future of sustainable fisheries in a changing ocean, and ICCAT should commit to managing its fisheries with the most up-to-date scientific tools. That starts with adoption of a new MP for North Atlantic swordfish this month.

Esther Wozniak works on The Pew Charitable Trusts’ international fisheries project.