BANGKOK — Two rare aquatic mammals are now officially listed as endangered due to poor fishing practices, marine experts said Wednesday.
The Irrawaddy dolphin and finless porpoise have been downgraded to endangered from vulnerable on the IUCN Red List in its annual update released Monday after their numbers in the wild fell into the hundreds.
“Numbers more than halved over the past 60 years for the Irrawaddy Dolphin, and over the past 45 years for the Finless Porpoise,” the IUCN said. “Both species live only in shallow waters near shore, and both have populations confined to freshwater systems, which makes them extremely vulnerable to human activities.”
Thai marine wildlife officials say they are alarmed about freshwater dolphin populations.
“There are only 22 Irawaddy dolphins left in Songkhla Lake. That’s their last natural freshwater habitat in Thailand. That’s extremely, horribly endangered,” said Weerapong Laovetchprasit of the Marine and Coastal Resources Research and Development Center in Rayong. “There are 200 more in Trat in the Gulf of Thailand, but even that number is still super low.”
As for the finless porpoise, he said his department has trouble tracking their numbers for their distinctive feature: the lack of fins makes it harder for scientists to spot them above water.
“Finless porpoises are the only type of porpoise found in Thailand. They have more numbers than the Irrawaddy, but their numbers are still decreasing very fast, counting from the beached porpoises we found,” he said.
They are prone to accidental entanglement in non-selective fishing nets – the primary cause of their decline. Further causes of decline include the overfishing of prey and habitat destruction.
Humans are the main cause of their decline, according to IUCN. People are tangling them in their nets, overfishing their prey, destroying their habitat and polluting their waters.
“A lot of times they will get tangled in ropes and drown because they can’t come up to the surface to breathe,” he said. “Other times, they ingest so much plastic that their bodies are completely rotten when we do an autopsy.”
Thailand is the last bastion for the Irrawaddy dolphin in Southeast Asia, Weerapong said, after the freshwater dolphin became extinct in Laos since November 2016, with only a few found in Cambodia, Indonesia and Myanmar.
Freshwater whales, dolphins and porpoises are vulnerable to extinction due to low breeding rates and land use by the river, Weerapong said, referencing the Yangtze river dolphin which went extinct in 2007 in China.
Weerapong asked people to stop using plastic bags and straws indiscriminately since many end up as marine debris and endanger animals.
“People think using plastic is a boring, stupid issue, but it’s really not,” he said.
Any beached marine animals, dead or alive, should also be reported into the the Department of Marine Resources’s research branches in Rayong, Samut Sakhon, Chumphon, Songkhla or Phuket for rescue or autopsy either through Facebook or by phone.
“Please don’t leave these rare aquatic animals to die like stray dogs,” he said.