30 May 2024

Some Pacific Island Countries and Territories run the risk of a significant dent to their revenues as climate change causes shifts in tuna abundance and distribution, research from the Common Oceans Program suggests.

Rising water temperatures, expanding low oxygen zones, ocean acidification, and more frequent extreme weather events are causing significant shifts in the accessibility, availability and trade of aquatic food products.

The Common Oceans Program is researching stocks in the ocean areas beyond national jurisdiction (ABNJ) to gather evidence that will support more effective management of fisheries. It consists of five projects including two with a focus on tuna and deep-sea fisheries. The project centred on tuna fisheries uses a physical-biogeochemical-ecological system to predict the effects of climate change on stocks by 2050.

Between 2016 and 2050, the model projects that catches – measured by combined biomass of skipjack, yellowfin and bigeye – will fall by up to 37 percent in Papua New Guinea, 26 percent in the Federated States of Micronesia and 15 percent in the Marshall Islands in the west but rise further east by 18 percent in the Cook Islands and 15 percent in Kiribati, according to the research.

As a result, the share of government revenue derived from tuna fishing licences is expected to decrease over the same period from 47.2 to 39.9 percent in the Federated States of Micronesia, from 45.1 to 41 percent in the Marshall Islands, and from 2.4 to 1.5 percent in Papua New Guinea. In contrast, further east, this figure is projected to rise from 54.4 to 57.9 percent in Kiribati and from 8.9 to 10.3 percent in the Cook Islands.

An increasing proportion of the future tuna catch is anticipated to be in the ABNJ rather than in Exclusive Economic Zones (EEZs). Selling fishing licenses is a significant source of government revenue in the region and the expected eastward shift in distribution would move tuna stocks outside EEZs where they could no longer charge for permission to fish.

This knowledge will empower stakeholders to enhance preparedness for economic challenges in the region.

Adapting to changing conditions

"There are many small island nations and territories in the Pacific that rely heavily on tuna fisheries. The goal of the modelling and forecasting is to provide crucial information for decision-makers to take action so that they can adapt in time to a loss of revenue from selling fishing licences," said Kim Stobberup, who is the manager of the Tuna Project in FAO's Fisheries and Aquaculture Division.

Accurate modelling and forecasting information is essential for the process of adaptation.

"There is much you can do to be able to cope with climate change. This wouldn't solve every problem for these countries in the future, but it would prepare them to adapt to this and come up with different strategies to cope," Stobberup said.

A shift in stocks to areas outside EEZs would also exacerbate challenges in monitoring and controlling fisheries.

Fishing tuna more sustainably

The region is the source of much of the world's tuna. Catches of the major species – skipjack, yellowfin, bigeye and albacore – amounted to 2.6 million tonnes in the Western Pacific in 2022 or around 54 percent of the global tuna total.

Strong demand for it provides food and jobs for millions of people, but also puts stocks under pressure.

The Tuna Project aims to ensure that tuna is fished more sustainably by mobilizing a global partnership in support of responsible tuna fisheries management and the conservation of biodiversity in the ABNJ. Management of the stocks is key to their future health.

During the first phase of the Common Oceans Program, 2014-2019, the Tuna Project helped reduce from 13 to five the number of most commercial tuna stocks experiencing overfishing in collaboration with the world's five Regional Fisheries Management Organizations (RFMOs) and other partners.

Consensus on developing harvest strategies – a pre-agreed approach to determine catch limits for all major commercial tuna stocks – has contributed to making tuna fisheries more sustainable and transparent in all five tuna RFMOs.

In the coming years, the Tuna Project will step up efforts to support further reductions in catches from stocks that are subject to overfishing, including tackling illegal, unreported and unregulated fishing, while enhancing its contribution to biodiversity conservation.

The future of the Tuna Project

In phase two of the Common Ocean Program, which started in 2022 and is due to run until 2027, the Tuna Project is refining the biomass projection model for the Pacific and extending the study to the Atlantic and Indian Oceans. This expansion aims to improve predictions and produce a more comprehensive understanding of climate-induced impacts on tuna populations and support effective decision-making in all tuna RFMOs.