Marine Protected Areas: There is a catch

Increasing marine protected areas could boost fishing – but there can be unintended consequences. We need an approach that works.

Could less fishing mean more fishing? The answer is yes according to a new study which claims that increasing marine protected areas (MPAs) by five per cent could boost future catches by at least 20 per cent.

Researchers at the University of California, Santa Barbara, say a modest increase in MPAs could generate an extra nine to 12 million tonnes of seafood per year with an estimated value of US$15 billion to US$19 billion.

MPAs, which restrict or ban certain activities, usually fishing, can increase not just the numbers of fish but also the size of the fish and the number of eggs laid. The larvae that hatch can help seed fish populations in the wider ocean as they drift outside the MPA while adult fish swim into less crowded waters beyond the protection of the MPA. These two effects are known as spillover, which researchers believe has the potential to swell global seafood yields.

“There are no doubts about the benefits of functioning MPAs from a fisheries management perspective, as inside the reserve, the numbers, size, and age of resident fish increases in response to reduced fishing pressure and human impact,” says New Zealand-based fisheries expert Francisco Blaha. “This leads to increased reproduction and net export of both adults and larvae into adjacent regions. Research also shows that diversity can increase.”

But MPAs are no silver bullet to the challenges of depleted fish stocks and threatened marine habitats. The right location is vital, with the most effective MPAs sited in productive inshore areas rather than unproductive and thus little fished remote areas of the open ocean. Large deepsea MPAs may be the easiest to implement because they don’t arouse the opposition of fishing communities but have a limited impact on fish stocks and marine diversity. Importantly, MPAs also need to come with real ‘teeth’: currently only 2.4 per cent of the world’s ocean area is deemed highly protected.

In the UK, for example, over a third of the waters are covered by MPAs but this doesn’t mean these vast offshore areas are out of bounds to fishers. Instead there’s a patchwork of different restrictions: not all the MPAs have fishing restrictions and, where they do exist, the rules may apply only to certain specified areas, certain types of vessel or certain times of year. Indeed, only four small sites, representing just 0.0024 per cent of the UK’s protected areas, ban fishing altogether.

Palau leads the way

One of the most ambitious MPAs was introduced in January 2020 by the Pacific island state of Palau, which, in a bid to improve its attractiveness to high-end tourists, enclosed 80 per cent of its exclusive economic zone to all forms of extractive activities. The remaining 20 per cent of the EEZ was designated as a domestic fishing zone to boost local fishers and support food security for the islanders. The hope was that local fishers would shift their focus from coastal reef fish and instead access the pelagic fish (such as tuna) previously caught by big international shipping fleets.

Unintended consequences

On paper, the policy seemed sound but in reality was holed by what the government admitted were “unintended consequences”. The pandemic sank the hoped-for tourism revenues, and the local fishing fleet lacked the capacity to go after the deepsea tuna, leading to a shortage of the fish in the local market.

“The challenges have mostly been enforcement, and unintended consequences of taking more reef fish than the pelagic fish,” said local journalist Bernadette H Carreon, who has provided extensive coverage of the policy. “The MPA should have enabled the local fishermen to catch more tuna, but this didn’t happen because of the complexities of fishing offshore, fuel costs, the need for bigger boats, and traditionally Palauans fish to subsistence fishing rather than supplying the domestic market.”

Scientists are now pushing to protect 30 per cent of the oceans by 2030 to create space for biodiversity, replenish fish stocks and build resilience to ocean heating. However, as one commentator puts it, this is more of an “aspirational number rather than based on evidence”. To deliver on their aims, the new MPAs will need to have real teeth.

“The effectiveness of an MPA depends largely on the effectiveness of the control over potential human impact,” said Francisco Blaha, stressing the need for increased attention to the practicalities of the monitoring and surveillance.

A holistic approach, which addresses the complexity of economic, environmental, social and cultural realities of fishing, will have the best chance of ensuring solutions that are sustainable for the ocean and those who rely on it for their livelihoods.   

Read more on the World Economic Forum website.

Amy McLellan is a journalist and author. She was previously editor of Energy Day.