EARTH Thailand

Fish out of water

Bangkok Post 16 October 2016 | Paritta Wangkiat

Polluted water is suspected in a spate of deaths of an endangered giant stingray

A rarely sighted creature -- the giant freshwater stingray -- was lying still on the bottom of the big blue tank.

The animal was exhausted but still looked majestic with its oval body measuring almost two metres in length.

Up to her waist in water was Nantarika Chansue, director of the Veterinary Medical Aquatic Animal Research Centre, tending to the animal in a Samut Songkhram facility. She placed an ultrasound machine on its dark brown back to examine it.

Two babies were alive inside, but the mother was paralysed. Its kidney was working hard in an effort to eliminate toxins from its body.

Dr Nantarika gets emotional remembering the scene from that day.

"Even if she was ready to be released, the environment wasn't ready for her return," she said.

On Oct 7, this giant mother was found bobbing at the mouth of the Mae Klong River in Samut Songkhram by local fisherman. It was dragged to shore for rehabilitation at the Samut Songkhram Fisheries Research Centre.

The next day, another giant freshwater stingray was brought to the centre from the river. It had three babies inside. Its back was wounded.

Since Sept 27, at least one dead stingray has been reported each day in the Mae Klong River, with the death toll rising to 54 on Tuesday.

Dr Nantarika examined the carcasses. Although some were stained with blood, most of them had stomachs full of food, suggesting that they died while they were still healthy.

Fish and clams in local farms have also recently been reported dead in rising numbers.

This has led Dr Nantarika to believe that the deaths might have something to do with toxin levels in the water.

Local conservation groups and activists on social media have spoken out in anger about the incident, with some also citing wastewater or toxic substances from nearby factories as the potential cause.

The Central Region's rivers have reportedly grown increasingly polluted, which would affect the giant freshwater stingray.

However, past cases of mass fish deaths show that it's always difficult to pin down a culprit.


Staying afloat: Nantarika Chansue performs an ultrasound on a stingray rescued from the Mae Klong River with two babies found inside. PHOTO: SUPPLIED/Dr Nantarika Chansue

One of the world's largest fish, the population of the giant freshwater stingray -- also known as the Himantura chaophraya -- has been rapidly declining in Thailand. It grows to about two metres in length, and can weigh as much as 600kg.

Chavalit Vidthayanon, an ichthyologist, said the global population of giant freshwater stingrays has declined between 60-80% in the past 30 years. Thailand has lost 90% of its freshwater stingray population in the same time.

There is now a 90% chance that it will go extinct in Thailand in the next 50 years if no serious protective measures are implemented. Their habitats range from rivers in the Central Region, the Mekong River and Borneo.

The International Union for the Conservation of Nature has named the giant freshwater stingray an endangered species. Thailand has put it on the Wildlife Protection List.

Around 200 giant freshwater stingray are now in Thailand, according to a VMARC study.

In recent years, some babies have been found, a positive sign of population recovery. But the recent mass deaths are causing fear about the future of the animal and the Mae Klong River.

"Giant freshwater stingrays are perceived as having little economic value," said Dr Nantarika, who has studied the animal over the past nine years.

"Despite the fact that they're endangered, no serious effort has been taken to preserve and recover the population. It's like nobody sees the emergency needs in this matter."

Thai researchers know little about the life and habits of the animal due to a lack of conservation studies and support.

The giant freshwater stingray can be caught and put in aquariums. Despite its endangered species status, some people still eat its meat, and its carcasses are also be sold cheaply for the leather or as a souvenir.

Dr Nantarika's research found that the animal's health is an important indicator of its environment's well-being. For example, the animal has shown it can detect environmental abnormalities. When wastewater contaminates the Mae Klong River, it usually migrates to a safer part of the river.

The recent stingray deaths tell of trouble in the water.


Confusion has shrouded the recent wave of stingray deaths. Environmental authorities and organisations have come up with different death toll numbers, and a lack of consensus on the cause of death remains.

Early last week, local authorities in Samut Songkhram recorded the number of dead since Sept 27 at around 20.

The Mae Klong conservation group asked local fishermen to report any findings of stingray carcasses. Over 50 dead were initially reported. Later, on Wednesday, local authorities updated the number to 46.

The Pollution Control Department released water quality monitoring results, saying the Mae Klong River showed normal conditions when the deaths occurred.

A Samut Songkhram Fisheries official said the deaths were not likely caused by polluted water but instead an abrupt oxygen shortage brought on by the rain, which sent damaging sediment downstream.

A team of experts at the Fisheries Faculty of Kasetsart University reported its own test results based on water samples collected from the Mae Klong River on Oct 7.

One litre of the river water was found to contain about one milligram of dissolved oxygen, much lower than the five milligram sample found one year ago. Ideally, the water would contain at least four milligrams.

Weerakit Joerakit, chief of the Samut Songkhram Fisheries Research Centre, led the Kasetsart University team to collect samples of Mae Klong water from downstream in Samut Songkhram to upstream in Ratchaburi on Tuesday.

The samples were sent to a lab to determine levels of nutrition, pesticides and heavy metal. It will take a week to get the results.

"Water quality is a big factor in determining the giant freshwater stingray's well-being," Mr Weerakit said. "The factory and agriculture sector have grown, which has affected the water quality and animal population."

The National Resources and Environmental Office Region 8, which monitors the Mae Klong River -- stretching 140km through Kanchanaburi, Ratchaburi and Samut Songkhram -- reported that its 2015 water quality survey of 12 stations along the river found most samples had a "fair quality" result.

Only one station in Ban Pong district in Ratchaburi reported having "degraded" water samples.


An ethanol plant in Ban Pong district in Ratchaburi came under fire after netizens released a video clip of wastewater being discharged from the plant into the Mae Klong River.

They suspected that it might have caused the stingray deaths.

Nisakorn Jungjaroentham, deputy permanent secretary of the Ministry of Industry, told the media on Thursday that collected water samples from the plant indicated their wastewater levels had exceeded safety standard levels.

The ministry plans to take legal action against the plant and sent more monitors to eight factories in Samut Songkhram. Nothing suspicious has been found there so far.

The Isranews website published a letter from Rajburi Ethanol Co Ltd addressed to the Mae Klong Basin Committee, a water monitoring body under the Department of Water Resources, admitting that on Sept 30, wastewater leaked from the plant's treatment pond into a rain gutter connected to the river.

The company has reportedly responded by blocking the leak and gutter, and pumping wastewater back into the pond.

"[We] didn't have any intention to let this happen," read the letter. "We are aware [of the incident] and we're responsible. [We] apologise to the local community. We're solving the [problem] immediately, and carrying out daily examinations of the wastewater system to prevent future incidents."

Many past cases of mass animal deaths failed to find any people responsible. For example, the dead fish stranded on the five kilometre-long Bang Saen beach in Chon Buri last year simply ended up being attributed to red tide.

"There's a lot of factories and industrial estates next to major rivers and along the coast of Thailand," said Penchome Sae-Tang, director of Ecological Alert and Recovery Thailand. "But we don't know much about the specific volume of pollution released into the water. We don't have any laws to force factory operators to hand out information about pollutant levels to the public.

"If we do, you don't even need to ring me [to find the theory behind the cause of stingray's deaths]."

In highly industrialised countries, such as the US and much of the EU, pollutant release and transfer register systems are used to collect and share information about how much toxic chemicals factories and other industrial facilities release into their nearby environment.

The system is based on the rights of workers and communities to know what toxic chemicals and other substances they could be exposed to.

Without a similar system that allows access to such information, Ms Penchome said it's hard to hold people accountable when these destructive environmental incidents take place.

Factory operators are required to submit annual reports with pollutant information to the Department of Industrial Works. However, Ms Penchome said it rarely releases all its information to the public.

When operators bring water samples for lab testing, toxic substances are seldom detected.

The residential sector has also been implicated in waste dumping, but those responsible are rarely identified and fined.

The PCD's Thailand Pollution Report from 2015 says the western region produced 475,742 cubic metres of community wastewater a day.

Only 22.7% of the wastewater was treated properly. Of all the provinces in the region, Ratchaburi was found to have produced the most wastewater.

On the national level, 9.59 million cubic metres of community wastewater were produced per day. Only 26.9% went through wastewater treatment before being released into the environment.


"I feel like the system never believes locals' stories," said Boonyuen Siritum, 55, a Samut Songkhram resident and a former senator. "Authorities have downplayed the impact of polluted water.

"But we're at the mouth of stream. We're the most affected."

Born and raised in a village at the mouth of the Mae Klong River, Ms Boonyuen has experienced the decline of water quality due to factory expansion, chemical usage in farming and dam construction upstream.

Rain usually drains wastewater, moving it downstream, and causes red tide at the river's estuary at least once a year. Coconut trees stand lifeless due to salt intrusion in the dry season when a dam upstream holds the water.

Since she was a child, she's seen giant freshwater stingrays in the river. It grows especially large when immersed in healthy water.

According to local anecdotes, one to two stingray carcasses are typically found annually, although there could easily be more unreported.

The recent wave of deaths represents an alarming spike.

In response, local conservation group Kon Rak Mae Kong has collected signatures to pressure the government to investigate the cause of the stingray deaths. They demanded measures to monitor factories and the environment of the Mae Klong River, both upstream and downstream.

On Oct 7, a fisherman, a neighbour of Ms Boonyuen, found five fatigued stingrays at the mouth of the Mae Klong River while out fishing. Some weighed about 200kg.

Because of their heavy weight, only one stingray managed to be dragged to shore.

When a group of fishermen returned to the same place a couple of hours later, the other four had disappeared.

The only survivor, a mother with babies, reached Dr Nantarika's care.

The fate of one of the world's largest fish and the Mae Klong River remains a whirlpool of uncertainty.