The World Wildlife Fund has called for closer cooperation between Cambodia and Laos to protect the Mekong River dolphin, in the wake of the death this week of a female thought to be one of less than 85 left in the river.

With a population in the thousands as recently as the 1960s, numbers of the Mekong River dolphin, also known as the Irrawaddy dolphin, have dwindled to the point that it is now listed as “critically endangered” on the IUCN Red List of Threatened Species.

“The key [to successful conservation] is collaboration between Laos and Cambodia,” said WWF-Greater Mekong Conservation director Teak Seng in the published statement.

In recent years, illegal fishing practices such as the use of explosives or poison, as well as the growing popularity of “gillnets” – vertical fishing nets that form a wall in the water and entangle dolphins – have been blamed for causing many deaths.

While Cambodia has banned gillnets and stationed rangers along the river to combat illegal fishing, Laos has been less stringent, and only five of the dolphins are now thought to reside there.

According to Ouk Vibol, director of the Fisheries Conservation Department at the Ministry of Agriculture, Forestry and Fisheries, coordination between the two nations is currently “poor”.

“The relationship is still weak; there are still a lot of gillnets along the border, especially on the Laos side,” he said.

However, Vibol says a projected meeting to discuss bilateral conservation efforts could take place as early as next month.

“It’s time to work on this,” he said. “We would like to update the agreement on both sides.”