Hans Nicholas Jong, Jakarta – Tri Atmoko is a regular visitor to the mangrove forests of Balikpapan Bay on the east coast of Indonesian Borneo, where he studies proboscis monkeys, an endangered species best known for its comically large nose.
He'd last gone there in 2022, he tells Mongabay recently. On his return this past June, areas of mangrove trees that were still intact before had now disappeared.
"I found many new developments," says Tri, a primatologist with Indonesia's National Research and Innovation Agency (BRIN), a government body. "I observed numerous logistic ports being constructed for [the transportation of] materials like sand and rock. Mangrove areas, which were previously intact, are being cleared to build these ports."
All that construction material is headed a few kilometers inland to the biggest construction site in Indonesia: Nusantara, the new capital city being carved out of the Bornean jungle. The development's footprint includes 3,000 hectares (7,400 acres) of mangrove forest, part of a 16,000-hectare (39,500-acre) mangrove belt that runs between Balikpapan Bay and the mouth of the Mahakam River.
Nusantara is the signature project of President Joko Widodo, who kicked it off in 2019 with the aim of moving the seat of government from the overcrowded and rapidly sinking Jakarta by the time he leaves office in October 2024. But the project has been beset by ballooning costs (with the total tab now at an estimated $33 billion), repeated delays, and a reluctance by foreign investors to get involved. And as Jokowi, as the president is widely known, rushes to get landmarks like the new presidential palace completed, the environment is also coming under pressure.
Tri says the ports being hastily built along the mangrove coast are part of this rush. To transport the building material and equipment, construction companies are using large barges, which damage the mangrove trees, he says: "These barges are too big."
Greenpeace Indonesia also recently reported clearing of an area of mangroves along the upper reaches of Balikpapan Bay for construction to make way for heavy machinery.
This poses "a significant threat to biodiversity," the NGO said.
"The destruction of these mangroves, combined with the massive increase in water traffic within the bay – a habitat for Irrawaddy dolphins, dugongs, and saltwater crocodiles – has disrupted the local ecosystem, leading to increasing conflicts between wildlife and local communities in recent years," Greenpeace said.
The increase in shipping traffic also creates noise pollution, disturbing the local wildlife, according to Tri. When animals like proboscis monkeys (Nasalis larvatus) get stressed, it impacts their reproductive rates, he adds. His most recent study puts the number of proboscis monkeys at about 3,900 in the Balikpapan Bay area, making this a key stronghold for the endangered species.
Myrna Asnawati Safitri, the deputy for environment and natural resources at the OIKN, the government agency overseeing the Nusantara project, confirmed the findings by Tri and Greenpeace. She said the OIKN has acted on those findings by issuing warnings to the companies clearing the mangroves and ordering them to replant the affected areas.
The OIKN has also filed charges with the police against one of the companies, Myrna added.
"We keep observing and monitoring [the mangroves] at the moment," she told Mongabay.
Inadequate biodiversity planning
The Indonesian government had promised that the construction of Nusantara, slated for completion in 2045, would not clear any protected forests, but its master plan for the new capital didn't mention anything about mangroves.
Tri attributes the clearing of the mangrove forests and disturbance of wildlife habitat inadequate biodiversity planning in the development plan. However, Myrna said the OIKN had incorporated Tri's study on proboscis monkeys into the section of its master plan to protect biodiversity and mitigate environmental harm in the region.
In March 2024, the OIKN rolled out this biodiversity management master plan amid mounting criticism of the environmental and social threats posed by the construction of the new capital city. It sets out a number of action plans to preserve wildlife habitat, protect species and restore damaged ecosystems through to 2029. The ultimate goal is to ensure 65% of the area of the new capital is tropical rainforest, by designating protected areas and rehabilitating degraded lands and forests.
Tri says he welcomes the master plan, but adds that it comes "a little too late": construction activity began as early as August 2022, nearly two years before the master plan was published.
"Such studies should have been done early on, before development started," he says. "With much of the land already cleared, it's now too late for effective planning. It should have been done earlier as the baseline for planning."
Myrna said in February that her office had taken some mitigation measures to protect the Balikpapan Bay ecosystem, including designating the mangrove ecosystem as a protected area, allocating a small island as a wildlife reserve, and conducting mangrove rehabilitation. She added that her team had reached out to local NGOs and civil society groups to involve them in monitoring and management.
But even as the master plan has been rolled out and protective measures implemented, deforestation persists – as does local resistance to the clearing of the mangrove forest, Tri says. Many communities in Balikpapan Bay rely on the mangroves as a source for wood, honey and traditional medicines, and as breeding grounds for commercially important fish species.
The continued clearing indicates the protective measures aren't being effectively implemented, despite the government's promise to make Nusantara a "green" city, Tri says.
He calls for more robust biodiversity planning and protective measures, especially given that Nusantara's footprint overlaps with 41% of the proboscis monkeys' habitat.
"Development [of Nusantara] must proceed cautiously, considering the habitat conditions and wildlife," he says. "Important areas [for biodiversity] should be legally protected to avoid significant changes to the existing landscape."