Harvest strategies, electronic monitoring crucial to healthy Pacific tuna stocks

by Peter Griffin | 1 March 2024 | Features, News

Source: MSC

In part 1 of this two-part series in conjunction with the Marine Stewardship Council (MSC), we look at the harvest strategies and eco-labelling practices helping to maintain sustainable tuna stocks.

With nearly half of the world’s tuna catch coming from the Western Central Pacific Ocean (WCPO) region, maintaining the health of the four key tuna stocks that are commercially fished there is crucial to the economic and social wellbeing of the island nations of the Pacific.

Since 1997, the Marine Stewardship Council has held a remit of informing the public about sustainably caught seafood and around 15% of marine catch have been certified to the MSC Fisheries Standard.

That figure is growing as more fisheries become MSC-certified, which requires them meeting a series of strict sustainability criteria which are independently verified on an annual basis. You can now select from over 20,000 MSC-labelled products in stores around the world, with 33 MSC-certified tuna fisheries in the WCPO region. 

“All the stocks in the WCPO are healthy, we are in a great position as far as that goes,” says Bill Holden, a former owner, operator and skipper of snapper and tuna longliners in the Kingdom of Tonga, and now the MSC’s Senior Tuna Fisheries Outreach Manager, based in Sydney.

“In contrast, there’s uncertainty about what is going on with bigeye tuna in the eastern Pacific, and yellowfin in the Indian Ocean has been overfished and overfishing continues,” says Holden, who works closely with fishing companies and associations to ensure they understand the requirements to achieve and maintain MSC certification.

“Retailers in the European Union are not keen on buying yellowfin from the Indian Ocean because of overfishing.” 

Read part 2 of this series: Trustworthy ecolabels the key to helping consumers make sustainable tuna purchases

Read part 3 of this series: How Pacific Island nations built one of the world’s largest sustainable tuna fisheries

Climate change a looming threat

While the status of Western and Central Pacific Ocean tuna fisheries is currently healthy, growing pressure on fish stocks from population growth, pollution, and climate make them vulnerable to rapid change.

Sustainability is increasingly driving consumers’ decision-making when it comes to buying seafood products, so MSC certification is highly sought after by fishing companies. 

“If you are not MSC certified, in some cases you don’t have access to the market.

“Fishing companies get a premium price per tonne if they are certified. It’s not like it was years ago, but in some cases, they are still getting an extra US$150 – $200 a tonne because it is MSC-certified,” Holden adds.

While success in maintaining the health of WCPO tuna fisheries has involved a lot of effort from Pacific island nations, scientists, NGOs and international funding bodies, Holden says there’s also been an element of luck involved, with many management processes still ad hoc in nature.

The Marine Stewardship Council is a major advocate of harvest strategies being put in place for the big four tuna fisheries in the region – skipjack, albacore, bigeye, and yellowfin.

“Harvest strategies is probably the one area where MSC is pushing the hardest at the moment,” says Holden.

“The big thing for MSC-certified fisheries is the successful management of the fisheries and the promotion of harvest strategies and harvest control rules.”

The MSC has certified tuna fisheries in the WCPO region on the basis that they are working towards having harvest strategies and harvest control rules (HCRs) put in place for each of them. The rules set out how much fish can be taken, and pre-agree mechanisms to control “fishing effort” – a measure of how much catch can be harvested from a fishery, should the fish stock decline below a sustainable level. Extensive scientific research informs the harvest strategies and harvest control rules.

Source: SPC


At a pivotal Western and Central Pacific Fisheries Commission (WCPFC) meeting held in Da Nang, Vietnam in December 2022, a non-binding agreement was struck to apply a “management procedure” (harvest strategy) for skipjack tuna.

In December 2023, a follow up meeting (WCPFC20) held in the Cook Islands saw some progress made towards a harvest strategy for albacore tuna, with the adoption of interim target reference points.

“I’m very optimistic about skipjack because of what is happening,” says Holden of the skipjack harvest strategy now in place for the WCPO region.

“But you never know what is going to come out of left field, like coronavirus, where there’s limited observable data for two or three years. Then there’s the impacts of climate change. If the bulk of skipjack moves further east in the Pacific out of the exclusive economic zones of the Parties to the Nauru Agreement (PNA), that’s a big loss of income for them.”

The priority now is to make the skipjack harvest strategy a success and get harvest strategies in place for the other key tuna fisheries. The non-binding nature of the agreement on skipjack was a bone of contention in Da Nang, and was a requirement of the eight PNA nations who wanted to retain the ability to adjust harvest via their vessel-day scheme, classed as an “effort-based control, rather than conform to a total allowable catch as part of a harvest strategy.

The rise of electronic monitoring

MSC’s Bill Holden.   Source: MSC

The MSC sees effective harvest strategies as crucial to the future health of tuna fisheries. But Holden says that improved electronic monitoring of fishing activity is also crucial to allow more visibility into fishing practices in the WCPO.

“I’m a firm believer in electronic monitoring which is an area that’s going to pick up pace,” says Holden who was the first fishing fleet operator in Tonga to introduce a vessel monitoring system (VMS).

“On my computer at home, I could see exactly where my vessels were. Back then, some skippers didn’t want to use it, they’d rip the cable out. Now no one even blinks about VMS. Electronic monitoring will be the same.”

Real-time monitoring of fishing activity via electronic record keeping, technologies like VMS, and cameras on boats, is being implemented by PNA nations and more broadly in the pacific, with remote sensing from satellites and aeroplane surveillance augmenting monitoring efforts.

Real-time monitoring will also help fishing companies meet environmental, social and governance (ESG) requirements increasingly required by tuna brands, retailers, investors and consumers.

“It’s very difficult at sea to monitor, for instance, the social aspects of workers conditions and rights,” says Holden.

“In future there may be a requirement that at least 30% of your data can be observed which could address labour issues.” 

Underpinned by science

The MSC already operates Chain of Custody certification for fishing companies, which examines fish sourcing and processing, but also scrutinises labour practices. MSC certification is also now a requirement among fishing companies by some bank lenders.

Negotiations on yellowfin and bigeye tuna harvest strategies will move up a gear this year, around a decade after the first MSC certifications were issued for albacore and skipjack fisheries in the WCPO region.

Crucial to setting science-based harvest strategies is maintaining scientific capability to carry out complex stock assessments, says Holden.

“Stock assessment scientists don’t grow on trees, tuna stock assessment is a very specialised scientific field,” he adds.

“But a lot of countries see the need to have these harvest strategies in place, because change is happening and they need to prepare for it.”