Recent scientific research highlights that tuna fisheries are facing the highest risks due to climate change, particularly among globally significant fish species. An extensive analysis covering over 500 fisheries certified by the Marine Stewardship Council (MSC) worldwide has revealed that highly migratory species, such as tuna and swordfish, are especially vulnerable to the effects of shifting ocean conditions.

The study, published in a leading sustainability journal, assessed the potential impact of climate change on the sustainable harvesting of popular seafood species, including fish, crustaceans, and mollusks. The findings indicate that top predator species with wide-ranging migratory patterns, like tuna, are at the greatest risk, followed by smaller schooling fish such as herring, mackerel, and sardines. Demersal whitefish species, including cod, plaice, sole, and monkfish, also face notable challenges but to a lesser extent.

Shifting Habitats Cause International Fishery Conflicts

As ocean temperatures rise, many migratory fish species are relocating to cooler regions. For instance, bluefin tuna have been observed in British waters, an area outside their traditional range, while tuna schools in the Pacific Ocean are gradually moving from western to cooler eastern areas. These habitat shifts mean that fish stocks are increasingly appearing in the territorial waters of countries that previously did not host them. This phenomenon often leads to competition and disputes between nations that have historically relied on these fisheries and those newly encountering these valuable species.

Such disputes can quickly escalate, resulting in overfishing and unsustainable practices. A recent case involving North East Atlantic mackerel demonstrates how stock migration can undermine existing fishery agreements, making it challenging to manage quotas and conserve stocks effectively.

Need for International Cooperation and Adaptive Management

Experts emphasize the urgent need for strengthened international cooperation to address these emerging conflicts and reduce the risk of overfishing. As migratory fish stocks move across political boundaries, current fishery agreements and quota allocations often become outdated. Flexible, adaptive management strategies are essential to respond to dynamic changes in fish populations and distributions.

Without updated and adaptable agreements, fisheries--even those committed to sustainable practices--may struggle to maintain healthy stock levels. The ongoing acceleration of climate change, coupled with rising global fish demand, requires governments and fisheries management organizations to adopt innovative approaches to protect marine resources and maintain food security.

Broader Impacts on Ecosystems and Food Security

Climate change is not only an ecological concern but also poses significant socioeconomic threats. Tuna, in particular, is a staple food source for many populations and a primary economic asset, especially for island nations in the Global South. As tuna populations diminish or relocate, countries heavily dependent on these fisheries may face severe economic consequences, potentially threatening livelihoods and food security.

Effective governance and proactive management by international fisheries organizations are critical to staying ahead of these changes. By working together, nations can safeguard fisheries, promote sustainable harvesting practices, and ensure that vulnerable communities are protected from the adverse impacts of climate-induced stock shifts.

Calls for Action Ahead of Global Climate Talks

With upcoming global climate negotiations, international organizations are urging fisheries nations to enhance their collaboration, implement cross-border fishery management measures, and take decisive steps to prevent overexploitation. The goal is to adapt to the realities of a changing climate while maintaining the long-term sustainability of global fish stocks.

While the research underscores that non-migratory fish species are also affected by ocean warming and acidification, migratory species present more complex management challenges due to their transboundary movements. Therefore, adaptive, science-based management remains vital for all types of fisheries in the face of ongoing environmental change.