The critically endangered Irrawaddy dolphin’s population in the Mekong is “stabilising”, the World Wildlife Fund said yesterday.
With the sighting of 10 new dolphin calves and six reported deaths in the past year, 2016 saw a 30 percent drop in the mortality rate compared to 2015, according to the statement, though the current population estimate of 80 remains far below the 200 estimated in 1997.
The group currently identifies hydropower dam construction, decreasing water levels and illegal fishing practices as major threats to the species. According to the group’s spokesman, Sambo Chheng, “most illegal fishing happens during the dry season, because dolphins and fish [are concentrated] in deep pools” along the Mekong when water levels reach their annual lows.
Community fishing patrols, he added, will be implemented in coordination with the Fisheries Administration starting this year to stave off illegal fishing. This strategy is similar to the use of patrols in the waters around the Koh Rong archipelago introduced earlier this year.
Earlier this month, Stung Treng-based environmentalists Chum Hout and Chum Hour noted that dolphins have become scarce near the construction of the Don Sahong dam. Today, they said it’s been two months since they’ve sighted any.
Chhum Kanika, an independent environmentalist based in the region says while there were once “six or seven” dolphins in the Chheu Teal pool near the dam, as of last month, she hasn’t seen any there.
“It’s all about the Don Sahong [construction]; the dolphins run away,” she said.
Chheng says the WWF has observed at least three individuals in the Koh Kabas pool 5 kilometres further downstream, a subpopulation he says the WWF considers to be “functionally extinct”.
An independent scientific study commissioned by the WWF in 2009 further identifies mercury and pesticide contamination as threats to the population. It also warns that the dolphin gene pool is now so small that inbreeding will render the population too weak to survive. The report’s assessment that the species was on the verge of extinction at the time drew the ire of the government, which went as far as to threaten the organisation with legal action.
Despite the study’s recommendation for further research, no comparable scientific surveys on dolphin mortality have been carried out since, only population surveys. Yesterday, WWF spokesman Chheng disavowed the 2009 report as “not official”, and denied the validity of its findings.
Several senior officials with the Fisheries Administration, which works with WWF in the preservation of the species, either declined to comment or could not be reached.