In many parts of Southeast Asia, including Malaysia, these crustaceans are not only a staple in the kitchen but also a crucial link in the marine food chain. But habitat loss from urbanisation, mangrove clearing, and coastal development is threatening their survival, along with the livelihoods of the people who depend on them.

A recent report by Indonesia’ s National Research and Innovation Agency( BRIN) highlighted the scale of the problem. The 2023 study, Sustainable Marine Fisheries Resource Management, found that Southeast Asia has lost as much as 7.5 million tonnes of fish annually.

This drop, driven by climate change, pollution, and the degradation of coral reefs and mangroves, represents an estimated USD 22.5 billion in economic losses.

The consequences are felt acutely in coastal villages such as Patimburak, West Papua, where crab fishing is a way of life. Adino, a member of the Togar Puan crab farming group, has witnessed the decline of the natural crab population due to overfishing and environmental degradation.

“ We realise this change is important for the sustainability of the marine ecosystem. That’ s what motivates

us, how the community can continue to utilise crabs without depleting their population,” he said.

RESTORATIVE AQUACULTURE

In 2020, the Indonesian non-profit Kaleka began collaborating with the Togar Puan group to address the issue. Early efforts faced obstacles, including the high cost and scarcity of suitable cultivation containers.

In 2024, however, the project returned with a new strategy— locally made, adjustable-size bamboo containers that villagers could build themselves. This simple innovation paved the way for greater involvement in crab cultivation.

Kaleka’ s Research Director, Venticia Hukom, explained the shift:“ This time, we are trying a new approach to crab cultivation with the restorative aquaculture method – a practice where aquaculture activities are carried out simultaneously with efforts to maintain crab stock in nature.

FEMALE CRABS: THE KEY

“ Each crab is placed in a separate container around the house of the Togar Puan fisher group leader, making it easier for the community to monitor growth. If a female crab has produced eggs, that female crab will be released back into the mangroves to ensure the sustainability of the crab stock.”

The method combines traditional knowledge with careful monitoring and observation. Crab weight, length, and width are regularly recorded, while ammonia levels in the water are measured to ensure conditions remain healthy.

“ This is done so that fishers understand the importance of maintaining water quality for the survival of cultivated crabs. Furthermore, by returning female crabs that have produced eggs, the community also learns how to maintain the crab stock in nature. Through this activity, it is hoped that the community will understand the importance of sustainable crab cultivation,” Hukom said.

Kaleka has also introduced an innovative 8-by-8-metre cultivation cage planted with mangroves for shade, capable of housing up to 100 crabs. The design creates a habitat that mimics natural conditions, promoting healthier growth while protecting the crabs from extreme sunlight.

For Adino, protecting the breeding females is essential not just for conservation, but for the local economy.

“ There needs to be public awareness on how female crabs should not be entirely harvested, but allowed to lay eggs and reproduce.

“ If preserved in large cages, it could even become an ecotourism attraction for Patimburak Village. Visitors could come and learn about the crab life cycle and crab cultivation,” he suggested.

The initiative has sparked discussions about introducing market regulations to control the harvest of female crabs. Advocates say such rules could stabilise natural stocks while keeping crab farming profitable for small-scale fishers.

This collaborative model, which brings together local communities, NGOs, and government support, demonstrates how restorative aquaculture can achieve both ecological and economic goals.

By integrating habitat restoration into commercial crab farming, the Togar Puan group is building resilience against climate change while preserving cultural traditions.

Kaleka, formerly known as Yayasan Inobu, has been championing such approaches since its founding in 2014. With a team of over 70 staff from across Indonesia’ s islands, the organisation focuses on sustainable landscapes and seascapes, always putting the needs of local and Indigenous communities at the centre.

Its work spans agriculture, conservation, food systems, and environmental governance. The core of its strategy is Collaborative Action Research, which blends scientific methods with local knowledge to test, adapt, and scale solutions that communities can own.

For the crabs— and the people— the work being done here might be the lifeline they both need.- @ green