Thirteen freshwater Irrawaddy dolphins have died between January and August of this year, depleting an already dwindling local population of the species, a conservation project investigator said.
With less than 100 Irrawaddy dolphins left in the Mekong River in Cambodia, the species could become extinct locally in the next 10 to 15 years if conservation measures aren’t immediately put in place, Isabel Beasley, principal investigator of the Mekong Dolphin Conservation Project, said Monday.
She said estimates show there could be as few as 60 dolphins remaining in the Mekong River, living between Kratie province and the Laos border. In the 1970s, she estimated, there were at least thousands inhabiting the area.
The majority of deaths occur when dolphins become entangled in local fishermen’s nets, which span between 300 meters to a kilometer, Beasley said.
“It usually happens when they’re accidentally caught,” she said.
River traffic, particularly large barges and ships transporting logs, also put dolphins at risk of death by collision, said Oum Pisey, deputy director of the Ministry of Environment’s Department of Planning and Legal Affairs.
Freshwater Irrawaddy dolphins are found in only three areas in the world—in the Mekong River, the Mahakam River of Indonesia, and the Ayeyarwady River in Burma, Beasley said.
Studies have shown “an alarming population decline” in all three areas, according to a 2003 status report from the conservation project.
The species, which reach as much as 2 meters in length and can weigh about 200 kg, produce only one calf every two to three years and don’t reach sexual maturity until they are 7 to 9 years old, adding to the population decline, Beasley said. They can live as long as 40 years.
Oum Pisey said the ministry is taking steps to protect the dolphins, including boosting law enforcement and educating boaters and fishermen about the high risk of accidental dolphin deaths.
But, he said, one of the biggest challenges remains in improving communication about logging and fishing activities between his own ministry and the Ministry of Agriculture.
He added that the Ministry of Environment is hoping to pass a law that would help conservation efforts by regulating development, fishing and recreational activities in certain protected areas. The bill is awaiting approval by the Council of Ministers.
Oum Pisey said that though the survival of the Irrawaddy dolphin is not considered a priority for the government, the government has a great interest in protecting the health of the environment.
“If you take one single species, I don’t think it’s a priority.” But, he added, “If you take biodiversity as a whole, I think it’s a priority.”