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Dolphin Numbers Fall, but WWF Still Hopeful

Over 400 people joined in WWF’s “Dolphin Day” celebration in Kratie town Tuesday morning, parading in dolphin-emblazoned T-shirts up the riverfront and through the market. Though local enthusiasm is palpable, the bottom line is sobering. The number of endangered Irawaddy dolphins in the Mekong River continues to drop, the WWF announced in a press conference following the celebration. A population that once numbered in the hundreds has now fallen to just 80 adult animals.

By Khmer Times/Aisha Down

Kratie, Cambodia, November 23, 2015

Khmer Times

KRATIE (Khmer Times) – Over 400 people joined in WWF’s “Dolphin Day” celebration in Kratie town Tuesday morning, parading in dolphin-emblazoned T-shirts up the riverfront and through the market. Though local enthusiasm is palpable, the bottom line is sobering. The number of endangered Irawaddy dolphins in the Mekong River continues to drop, the WWF announced in a press conference following the celebration. A population that once numbered in the hundreds has now fallen to just 80 adult animals.

Reasons for Hope

Though the dolphin population seems to be declining, both Chhith Sam Ath, country director of WWF, and Ouk Vibol, director of the Fisheries Conservation, emphasize that the outlook for dolphin survival is essentially positive. “The decline is slowing, firstly,” says Mr. Samath. “Around 2002, we had 14 to 15 dolphins dying every year. Now, it’s more like six to seven.”
Some deaths are natural, he explains. “Dolphins die of old age, just as people.”

In 2015, seven dolphins died, two of them from what are believed to be natural causes. The other five deaths, however, were likely a result of illegal fishing.

Moreover, says Mr. Sam Ath, the WWF believes that the dolphins have more calves than they did before. “In the early 2000s,” he says, “the number of dolphin calves was quite small, though we don’t have a total. Now, we believe there are at least 10 or 15.”

Mr. Vibol says the number could be even greater. Dolphin calves take seven years to mature to adulthood, and often don’t yet have markings on their fins. Therefore, a firm total cannot be established. “The dolphin count could well be over a hundred,” he says.

Counting Fins

Counting dolphins is difficult work, says senior researcher Phan Channa. The WWF sends out its six-man survey team during the dry season, when the river’s waters are low enough that the dolphins remain mostly in the Mekong’s deep pools. The survey team makes three research expeditions per dry season.

They begin at Kratie town and zigzag 180 kilometers upriver to Ochheuteal, just south of the Lao border, photographing every dolphin group they encounter along the way. Returning, they photograph each group a second time. One expedition takes 10 days.

Once a few years’ photographs have been collected, the research team begins to count the dolphins – or dolphin fins, rather. Each of Cambodia’s Irawaddy dolphins has distinct markings on its fins and body, says Mr. Channa.

Photographers on the team are trained to snap the dolphins at a 90-degree angle to the boat, aiming at these dorsal fins. It takes months to crop and process the resulting photos, and from them to extract the total number of distinct fins and distinct dolphins – but Mr. Channa is confident in the team’s methodology.

“I’m sure some dolphins are missed during a survey,” he says. “We can’t guarantee everything. But we do these surveys again and again and again.”

Dangerous Waters

Mr. Vibol and Mr. Sam Ath described a number of threats to the dolphin population. The most significant cause of dolphin deaths has been, they say, illegal fishing on the Mekong – both because it depletes the dolphins’ food source, and because gillnets have been known to strangle young dolphins.

However, these particular dangers are mitigated by the efforts of WWF’s River Guards, 65 locals who patrol the waters from Kratie town to the Lao border.

Most worrisome, they say, is the Don Sahong Dam, the construction of which is scheduled to start between two Laotian islands at the border before the end of this year.

Mr. Sam Ath predicts that the four dolphins at the Ochheuteal pool near the Cambodia-Lao border will be the first to be adversely affected: “They’re pouring 1 million tons of concrete into the waters,” he says. “It will be noisy, pollute the river, and kill the fish – it’s hard to imagine how the dolphins won’t be hurt.”

The effects of the Don Sahong Dam promise to be far more wide-ranging than Ochheuteal, says Mr. Sam Ath. The dam will affect water flow and migrating fish populations all along the lower Mekong. Dolphins, as a keystone species, are strongly affected by the overall health of the ecosystem – if the fish and flow of the river change, they will suffer.

However, Mr. Sam Ath and Mr. Vibol say negotiations with Laos on the subject of the dam remain fruitless. “260 megawatts is not much electricity, considering how the dam will affect the livelihoods of millions along the river,” says Mr. Sam Ath.

“What we want is for there to not be a dam,” Mr. Vibol said. “But, if it’s going to happen, we must start thinking of how to go forward.”

 

Lead image: WWF Greater Mekong

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