Jamil stood at the water’s edge holding a bucket of fish guts and chicken heads, waiting for signs of life as the late-afternoon sun cast a sheen over the pond.
“At this time of day, they’ll start becoming active and feeding,” said Jamil, 63, as the onshore breeze settled and the light began to fade. “In the morning, they’re more likely to stay in their holes.”
Until recently, the mud crabs (genus Scylla) were almost entirely a product of the wild here in Sugian village on the Indonesian island of Lombok. Fishers would set traps in the estuary and sell their catch to traders, with little incentive to spare juveniles or undersized animals.
“If you sell them immediately when they’re small, they’re cheaper,” Jamil said.
But when crab populations fell from overzealous fishing, so too did local earnings here in a region of Indonesia where many families struggle to remain together in the face of economic pressures.
Few places in Indonesia endure more family separation than the district of East Lombok. Last year it topped the list of Indonesia’s more than 500 districts for the highest number of its residents who left for work overseas. The minimum wage set by the local government for this year is 2.7 million rupiah (US$150), less than half that in the capital, Jakarta.
Last year, around 14,000 people — about 1 per cent of East Lombok district’s total population in one year — received permits to work overseas. Mothers usually become domestic workers in the Middle East, while fathers often leave for jobs as ship crew via Taiwan, or as labourers on oil palm plantations in Malaysia.
Like many people here, Jamil became alarmed by the dwindling availability of the crabs that used to be abundant in Sugian’s brackish mangroves.
Unlike many farmed aquatic species, mangrove crabs succeed in the muddy, sheltered conditions of mangrove ecosystems. By trapping sediment and reducing water flow, mangroves nurture the turbid habitat in which the crabs flourish.
“These crabs don’t thrive in high visibility — they’re more comfortable in slightly more dense, murky water,” said Herman, who leads a local community fishing organisation, known in Indonesia as a Pokmaswas.
In Sugian, awareness of the animals’ preference for mangroves combined with anxieties over dwindling numbers prompted local people to combine mangrove planting in dedicated cultivation areas, a practice known as a silvofishery.
“
If the habitat is good, the crabs will return — so cultivation is important, but the natural environment must also be restored.
Muslim, head of the fisheries department, West Nusa Tenggara
Deeply rooted
Indonesia hosts around 3.3 million hectares (8.2 million acres) of mangrove forests, the largest estate in the world. Yet studies indicate up to 40 per cent has been degraded or cleared, with crab, fish and shrimp cultivation emerging as the major driver of deforestation since the 1980s.
A government pledge to plant 600,000 hectares (1.5 million acres) of mangroves to arrest this decline by 2024 ultimately achieved only a fraction of its goal.
The silvofishery where Jamil now earns a living represents a response to one of Indonesia’s enduring environmental dilemmas: how to support livelihoods from aquaculture, a leading cause of mangrove deforestation, while sustaining the coastal ecosystems on which many fisheries ultimately depend.
“If the habitat is good, the crabs will return — so cultivation is important, but the natural environment must also be restored,” said Muslim, who is the head of the fisheries department in West Nusa Tenggara, the province where East Lombok district is located.
In principle, silvofishery represents a circular economy, where mangroves can be protected while boosting productivity from a commercially valuable fishery vital to local food security and Indonesia’s external account. The country’s aquaculture exports were valued at US$5.5 billion in 2021, according to the Food and Agriculture Organization.
Mangrove roots provide shelter, stabilise temperatures, and support the microorganisms and nutrients on which mud crabs depend. In turn, the crabs dig holes that aerate sediment and cycle the nutrients, which supports the health of the forest.
However, while crab farmers in Lombok point to benefits, silvofishery arrangements are not seen as a practical solution for the broader aquaculture sector.
“Shrimp farms are an enclosed system. The leaves of the mangrove trees in an open area become fertiliser [when they fall], but when they’re in an enclosed space they become rotten,” Muhammad Ilman of conservation nonprofit YKAN said in 2022.
For cultivation of mud crabs, however, the system shows promise. In 2022, researchers from Java looked at soil and crab quality at a mangrove forest recently planted to protect against coastal abrasion in Brebes district, on the north coast of Java, the world’s most populous island. The researchers found the healthier mangroves supported the population of mud crabs.
However, officials say limited access to extension services and technical training has left many farmers to learn mangrove restoration largely on the job, refining cultivation methods through trial and error rather than formal instruction.
“They are left to learn for themselves and find their own way,” Herman said.
In Sugian, fishers established belts of mangrove seedlings around pond embankments, inlets and corners. Over time, they adapted their methods, reinforcing young trees to prevent them from being washed away by tides.
“These fish farmers need guidance,” said Nurrahman, a fish farmer in Sugian. “Otherwise they’ll try it on their own, and the risk [of failure] is high.”
Local officials attribute part of the challenge to a shift in governance. Under reforms introduced in 2014, authority over coastal waters was transferred from district administrations to provincial governments.
“Responsibility for coastal areas up to 12 nautical miles [22 kilometres] was transferred to the province,” said Mastur, head of the East Lombok fisheries agency.
For farmers such as Jamil, the result is a system in which experimentation often substitutes for expert support.
“We’re learning on our own,” he said. “If we fail, it’s our own loss.”
A short walk from the pond, Jamil’s wife, Eli Ernawati, sorts through mud crabs that he’s gathered, separating the catch by size and destination.
Some will be sold to traders, others directly to customers. On good days, she said, the earnings are enough to support the household.
“When we were busy, it was enough to cover the household’s needs,” Eli, a mother of three, told Mongabay Indonesia. “But when things were quiet, we had to be smart about managing things.”
This story was published with permission from Mongabay.com.
