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Fishing is big business in the South China Sea and Gulf of Thailand. The industry supports amillions of people in the region and accounts for some 10 per cent of total global fisheries production every year.

But the region’s success as a seafood exporter has come at a cost – the depletion of local fish stocks, environmental damage and, ultimately a decline in food security and livelihood opportunities for local communities.

Once a small-scale industry, dominated by individual fisherman using nets and traps, fishing in the South China Sea and Gulf of Thailand saw a rapid expansion following the introduction of trawlers in the early 1960s, leading to overexploitation, stock depletion, and changes in ocean ecosystems.

Today, the region’s fisheries are under more pressure than ever, with growing populations, overexploitation of marine resources and poor enforcement of fishing regulations converging to threaten both local marine ecosystems and the communities they support.

Sealife under pressure

“It is vital that fisheries in the South China Sea and Gulf of Thailand are managed sustainably,” said Dr. Somboon Siriraksophon, Project Director at the Southeast Asian Fisheries Development Center (SEAFDEC).

“These ecosystems are under intense pressure, and amongst the world’s fisheries expected to be most impacted by ocean warming due to their location and the surrounding developing economies.”

Dr. Somboon is part of the team behind the South China Sea Fisheries Refugia initiative, a Global Environment Facility-backed effort led by the UN Environment Programme (UNEP), aiming to build the resilience of Southeast Asian fisheries and reduce marine degradation at the intersection of the South China Sea and Gulf of Thailand.

One of the key species in the project team’s sights has been the blue swimming crab. The crabs are a top export for Thailand, with the country ranking as the world’s fourth largest exporter over the past two decades. But they are under threat. Traditionally caught by small-scale and commercial fisherfolks using crab traps and bottom gillnets, the blue swimming crab population has suffered from large scale trawling operations, with the species frequently caught as bycatch by trawlers in both coastal and offshore areas.

Change from the bottom up

While the Fisheries Refugia project identified the need to protect the crabs –particularly the egg-bearing, or ‘berried’, females – the challenges in establishing wide areas as refugia led the team to work directly with trawler crews to release crabs caught as bycatch back into the sea.

“Social media has proved to be a very useful to help change the attitude of trawler crews,” Dr. Somboon says. “Using platforms like Facebook and Line, many fishermen are now recording and sharing videos of themselves releasing crabs back into the sea – helping spread the word on the importance of releasing bycatch, as well as providing data on the numbers of crabs released.”

By December 2019, crews from 45 trawlers were participating in the release programme in Thailand’s Surat Thani Province alone – with over 4,000 berried female crabs returned to the sea to spawn.

At the village level, SEAFDEC has taken a different tack, building on existing local practices to create ‘crab banks’. Berried crabs caught by small-scale fishmen are deposited in the local crab bank until they spawn, after which the adults are sold at market and the eggs or crab larvae returned to the sea. With fishermen earning 50% of every sale, and the remainder going to the ‘bank’ to cover cage maintenance and operating costs, the model of improving both livelihoods and environmental management has been a hit and has recently been expanded other coastal areas of Thailand, as well as to other ASEAN nations.

From release to refuge

The Fisheries Refugia project is also working actively with Thai authorities to establish refugia for key species – from the blue swimming crab to short mackerel, longtail tuna, mitre squid, orange-spotted grouper, rabbit fish, mangrove jack, tiger shrimp and spiny lobster. These are areas where the species can spawn and rebound with the help of seasonal closures, restrictions on equipment (such as gear likely to trap larvae), and rights-based approaches to small-scale fishery access.

“In the years gone by, we worked hard to ensure sustainable fisheries, but today we realize we also need to be a part of the sustainable ocean, that the oceans keep us alive, and that we need to work more carefully through the Fisheries Refugia Approach,” Somboon Siriraksophon says. “In this way, integrated fisheries and environmental management can ensure healthy oceans, benefiting both present and future generations.” 

Backed by the project, the Thai Department of Fisheries is now in the process of establishing refugia for blue swimming crab in Surat Thani Province’s Bandon Bay, including plans for seasonal closures to protect the berried female blue swimming crabs and their larvae.

“In situations of high small-scale fishing pressure and declining fisheries resources such as in the South China Sea basin, conventional fisheries management approaches are not  effective,” UNEP International Waters expert Isabelle Vanderbeck says.

“The Fisheries Refugia approach, mimicking the concept of natural refugia and not simply a no-use area, is a novel management approach which boosts local livelihoods  and enhances the resilience of fish stocks to the effects of fishing. Kudos to Thailand for supporting our ocean health!”

The Establishment and Operations of a Regional System of Fisheries Refugia in the South China Sea and Gulf of Thailand project is part of the Global Environment Facility-funded South China Sea project, aiming to reduce marine degradation at the intersection of the South China Sea and Gulf of Thailand.

For more information on the South China Sea project and UNEP’s work in International Waters,  contact [email protected].