- The ecosystems of East Kalimantan province in Indonesian Borneo face increasing pressure due to mining, logging, industrial agriculture, infrastructure projects, and a plan to establish a new administrative capital city.
- One of the species imperiled by this rapid transformation is the Irrawaddy dolphin.
- Estuarine populations of the species already face severely negative impacts from increasing shipping traffic and coastal development in Balikpapan Bay.
- A critically endangered population of freshwater Irrawaddy dolphins living in the middle reaches of the Mahakam River are also under increasing pressure due to climate change, oil palm cultivation, coal mining and transport.
Danielle Kreb, scientific program manager at the Conservation Foundation for Rare Aquatic Species of Indonesia (YK-RASI), knows this scene well. She suspects climate change is behind the sudden water level fluctuations that catch the dolphins unawares. Local fishermen report such strandings to her to be rescued with the help of her colleagues and enthusiastic community volunteers.
“There is a lot of motivation in the local community to help the dolphins,” she says. “Together, we have halved dolphin mortality by saving stranded dolphins and releasing them from fishermen’s gillnets.”
While organizations like YK-RASI strive to safeguard the dolphins, industrial expansion and extractive industries encroach further inland from the coast in Indonesia’s rapidly developing East Kalimantan province. Few natural habitats are safe from impact, and recent studies suggest the province’s dolphin populations are buckling under the pressure of development.
The Mahakam River meanders 980 kilometers (610 miles) from its headwaters in the heart of Borneo’s lush, old-growth rainforest, where orangutans, rhinoceroses and elephants still co-exist. It traverses East Kalimantan, past oil palm plantations, open-cast mines and timber yards, to a splintered delta into the Makassar Strait on the island’s east coast. It is a lifeline for the communities that farm along its banks and fish its main channel and the shallow lakes of its peat swamps.
The freshwater Irrawaddy dolphins’ main refuge is a 93-km (58-mi) stretch in the middle reaches of the Mahakam, between the districts of Kutai Kartanegara and West Kutai. Although the majority of the species is distributed in coastal waters across southern Asia, the Mahakam dolphins represent one of three riverine populations in the world; the other two are found in the Mekong and the Irrawaddy rivers. Latest population estimates suggest just over 80 dolphins remain in the Mahakam, with five to six calves born each year. Evidence from DNA studies confirms they are genetically distinct from the Irrawaddy dolphins that live along the coast and in Balikpapan Bay, a rapidly urbanizing port city 120 km (75 mi) to the south.
Dolphins face growing pressure as development eats into Borneo’s interior