Work is currently underway on a bridge and access road that will connect the fast-growing city of Balikpapan with its rural outskirts.

The project is part of a broader government program to transform Indonesian Borneo into an economic powerhouse.

Conservationists have opposed the project since it was launched in 2008, fearing it will disrupt marine life, cut a crucial wildlife corridor and spark land speculation and encroachment along a protected forest.

BALIKPAPAN, Indonesia — Truck driver Bayu Santoso is one of thousands of people expected to take advantage of a planned bridge connecting the fast-growing city of Balikpapan to its rural outskirts.

Transporting goods from Sepaku — a remote area in East Kalimantan Province’s North Penajam Paser district — to Balikpapan, Santoso currently relies on a ferry service that takes around 90 minutes to cross Balikpapan Bay. The 800,000 rupiah (about $60) return ticket means he can only afford one trip per day.

“The ferry ticket is so expensive that it’s such a burden for us,” he told Mongabay. After gas and other expenses, he usually brings home around 100,000 rupiah per day.

Such connectivity problems are common in Kalimantan, the Indonesian part of Borneo. While the island is world famous for its lush and biodiverse rainforests, the government hopes to transform the area into an economic powerhouse. The “Kalimantan Economic Corridor,” focused on developing the island’s extractive industries, is one of six priority areas in the central government’s 2011-2025 development master plan.

Upgrading the island’s transport infrastructure is a key part of that strategy, and the planned bridge — known as Pulau Balang for the isle that anchors its center — fits right in.

However, the project has drawn protests from conservationists and some locals due to its expected environmental impact. Since the project kicked off in 2008, conservationists have pointed to an alternative route they believe would solve connectivity problems while reducing environmental impacts — but work is already underway, based on the original plans.

Ongoing construction of the bridge and its access road has already disrupted marine life in part of the bay and cleared strip of forest on the Balikpapan side that served as a vital connection between mangrove and forest habitats. Still, the local government has vowed work will continue, while promising that environmental damages will be kept to a minimum. The project, they say, could be an exemplar of green infrastructure in Indonesia.

‘It’s killing us’

The proposed bridge consists of two spans, connected by Balang Island, which sits near the northern tip of Balikpapan Bay. The shorter traverse, which stretches 470 meters (1,542 feet) to link North Penajam Paser and the isle, was completed in 2013 and cost the provincial budget 425 billion rupiah.

Lack of funding, however, put the project on hold for two years. In 2015, the central government of President Joko “Jokowi” Widodo took over the completion of the bridge as part of his ambitious plan to develop infrastructure outside of the crowded Java Island.

State-owned contractors PT Hutama Karya and PT Adhi Karya, and local builder PT Bangun Cipta Kontraktor were appointed to develop the final span (804 meters) to Balikpapan and its supporting infrastructure.

While the benefits of the bridge are still on paper, its development has already caused significant environmental damages to the surrounding land and marine ecosystems.

“Balikpapan is one of the most biodiverse cities in Asia. It hosts the last remaining coastal primary rainforest in the region still connected with adjacent marine ecosystems such as special mangroves, seagrass beds and coral reefs,” said Stanislav Lhota, a primatologist at the Czech University of Life Sciences, who has done years of research on the rainforest in East Kalimantan.

A variety of mangrove trees standing at over 20 meters tall stretches along the northern coasts of the Balikpapan Bay and around Balang island — a view that gives a stark contrast to most of the southern edge of the bay, which is crowded by settlements and industrial complexes.

The playful calls of the Endangered proboscis monkey (Nasalis larvatus) can be heard instead of the ear-assaulting racket of machines and engines. Some 1,400 individuals of the species are estimated to flock the mangroves of the Balikpapan Bay.

But the development of the bridge has already seen swaths of the mangrove ecosystem replaced by concrete pillars and a 50-meter wide road. This, scientists fear, will create dangers and difficulties for monkeys as they move around looking for food.

The coral-rich waters around Balang Island are the core habitat of the Vulnerable Irrawaddy dolphin (Orcaella brevirostris), according to the marine conservation group Rare Aquatic Species of Indonesia (RASI) Foundation.

The loss of mangroves and coral reefs due to the bridge development have also jeopardized the local small-scale fishing community, who say “economical fish” are no longer found swarming the bay or the rivers.

“The bridge development was another blow to us traditional fishermen on the coast of Balikpapan Bay who, for the last several years, have been affected by the development of industrial zones,” 49-year-old Darman, who like many Indonesians have only one name, told Mongabay earlier this month.

The ongoing development of the 5,130-hectare Kariangau Industrial Zone (KIK) has since 2007 been blamed by conservation groups for degrading the quality of Balikpapan Bay and threatening the Sungai Wain Protection Forest, home to scores of the Vulnerable sun bear (Helarctos malayanus), which is the mascot of Balikpapan.

Darman, who lives in the fishing village Gersik in North Penajam Paser, said his parents and grandparents, who were all full-time fishermen with wooden boats, could afford the Islamic pilgrimage to Mecca, known as hajj. He, meanwhile, only catches enough fish to meet his family’s basic needs.

“The local government keeps saying that this infrastructure will improve the economy of people living on the coast, but what I’ve experienced so far is the complete opposite — it’s killing us,” he said.

The privately-owned factories mushrooming on the coast create some job opportunities, Darman said, but not enough to take on all of the fishermen who will need to find new livelihoods if fish stocks continue to decline. Companies also often end up hiring outsiders who have better education and the required skills, he added.

“They promised us new jobs, but what we’ve all been doing all of our lives is fishing, and now our only source of life is being destroyed,” he said.

Even truck driver Santoso said he couldn’t be completely positive about the upcoming bridge until he experiences it himself.

“Maybe I won’t be spending as much as by going with ferry. However, I personally don’t see this project as highly beneficial for independent truck drivers as much as it will be for the companies. It’s just a way to expand the city,” said Santoso, noting that the route to the bridge, which sweeps in an arc north of the city would be a challenge in itself.