Tuna fisheries need careful management in a warming world

by Lisa Buchanan | 30 June 2023 | News

Climate change is impacting the marine environment in numerous ways.

By Lisa Buchanan, Chief Technical Adviser, Oceanic Fisheries Management Project 3

Lisa Buchanan

I’m a marine biologist by training, so my new role with the Oceanic Fisheries Management Project (OFMP) has given me a golden opportunity to ‘go deep’ on one of the most majestic of fish species – tuna.

Skipjack, yellowfin, bigeye, albacore and prized bluefin tuna that inhabit the Pacific Ocean are not only amazing animals, among the fastest swimmers and nimblest predators in our oceans. They are also prized as sources of sustenance for Pacific Island communities, as well as returning much-needed export revenue.

Tuna is in great demand all over the world, from the sushi bars of Tokyo to the supermarkets of Europe. While many other fish stocks are in decline due, in large part, to pressure from fishing, the four main tuna stocks found in the Western and Central Pacific Ocean are sustainable, and not being overfished.

Overfishing occurs when the proportion of fish being caught is greater than the population replacement through natural reproduction ie: too many fish are being removed from the population.

Source: FFA

The most recent Tuna Fishery Assessment Report released by the Secretariat of the Pacific Community (SPC) in 2021, found the four target species to be in a “healthy and sustainable” state. That’s a credit to the collective effort of Pacific island nations over several decades, working in conjunction with the seafood industry, scientists, conservation groups, and fisheries management organisations like the Pacific Islands Forum Fisheries Agency, which implements OFMP3, the third iteration of this long-running project. You can find out more about OFMP3 our objectives and our partners here.

The various Oceanic Fisheries Management Projects, funded by the Global Environment Facility (GEF), and the United Nations Development Program (UNDP), have over the last decade provided valuable evidence-based tuna fisheries advice, training and support to Pacific small island developing states (SIDS).

Under OFMP3 we continue the streams of work that have proven to be highly effective, from informing best practices for fisheries management to helping ensure effective monitoring of fishing operations is in place.

OFMP’s way of working hasn’t changed – we are highly collaborative, reflecting the needs of our partner organisations and the nations represented by the SPC.

But OFMP3 strengthens our focus on understanding the impacts of climate change and on helping improve the resilience of island communities who will have to deal with changes in the marine environment.

The latest scientific evidence suggests that under continued high emissions scenarios, total catch across tuna species is predicted to be maintained until 2050, but then decrease later in the century.

However, that scenario is dependent on continuing sound management of tuna fisheries. Over the coming decades, tuna species are expected to migrate eastward in response to increasing ocean temperatures and also decreasing amounts of dissolved oxygen in seawater, which affects the metabolism of marine organisms. It’s not just that the quantity of fish available to Pacific Islands countries and territories (PICTs) may decline, but tuna may shift out of the exclusive economic zones (EEZs) of those countries and territories, and into high seas areas where there are little or no regulations governing fishing.

Production of coastal fish living just above the sea floor (demersal fish) is predicted to decline by 20% in 2050 and 20-50% by 2100 under continued high emission of greenhouse gases.

Avoiding the worst impacts of climate change

It is imperative that every country mitigates its greenhouse gas emissions to avoid the worst impacts of climate change. Whilst PICTs are at the forefront of the impacts of climate change, they are not big greenhouse gas emitters themselves. So their focus is on adapting to the impacts of climate change while supporting efforts underway globally, such as through the Intergovernmental Panel on Climate Change (IPCC) to mitigate global emissions.

However, some of the warming is already locked in. Pacific Island nations in the future may not be able to rely on having the same abundance of tuna stocks that exist today.

For that reason, OFMP3 has a very strong adaptation theme. We want to help communities diversify their economic activity so they can reduce their reliance on tuna. For instance, we are funding a project in the Cook Islands that is aiming to develop a sustainable sea turtle tourism operation. Many such initiatives will need to be explored as Pacific Island nations adapt to climate change.

While I am a marine biologist, the bulk of my career has been spent working with First Nations people, including Torres Strait Islanders, to tackle environmental issues in the Great Barrier Reef Marine Park and elsewhere around the coast of Australia. This is my passion – collaborating with communities to preserve the environment while making sustainable use of natural resources.

I have joined the OFMP effort at such a great time. The Pacific Island tuna fisheries are in very healthy condition. But maintaining that status will require us to work harder than ever with our partners in this venture, in the face of a changing climate.

As I look to relocate my young family from Canberra to beautiful Honiara I’m excited about the opportunity we have to manage a resource that, with careful planning and good leadership, will continue to mean so much to the people of the Pacific.