A resident secures one of the 15 dead Giant Stingrays found floating in front of Wat Khu Thamsathit in Khlong Bangkantaek, which is linked to the Maeklong River in Samut Songkhram’s Muang district.
Photo: Pattarapong Chatpattarasill

Thailand: Stingray deaths spur checks
Pollution dept orders toxic discharge tests
By Apinya Wipatayotin, 12 October 2016;

Wastewater discharged from factories is likely to be behind a sudden spike in deaths of Giant Freshwater Stingrays (Urogymnus polylepis) in Samut Songkhram, but lab test results may not be able to provide a link to the culprits, says the Department of Pollution Control.

A lab test is needed to clarify the source of chemicals or toxic substances that killed the Rays and is expected on Friday, said Wicharn Simachaya, the department’s chief.

His team collected samples of water and sediment from different spots along the Mae Klong River, from Samut Songkhram to Kanchanaburi, for tests to identify heavy metals and chemicals that might point to the cause of the unusual deaths.

At least 15 Stingrays have been found dead since Sept 29.

Even with the lab findings, it will be impossible to single out the factory that discharged the wastewater, he said.

“Most factories are using the same chemicals, so it’s difficult to point to a wrongdoer,” he added.

The high death rate prompted authorities to collect more samples from nearby Don Hoi Lot, a local source of Razor Clams (Solen sp.), which have also started dying.

Meanwhile, Nantarika Chansue, a vet from Chulalongkorn University who disclosed the spike in deaths of the rare species of Rays on her Facebook, insisted tests showed the cause of the deaths was not natural, citing findings by the Animal Health Institute that found toxic contamination in the livers and kidneys of some of the dead Stingrays.

Toxins were found at 20 times the normal level which showed the kidney had to work hard to get rid of the toxin from their bodies, she said.

Three survivors being nursed also showed similar symptoms of being paralysed, resulting from toxic contamination.

“We can’t tell what kind of factory released the toxins, but it was clear the toxins were not from the farming sector because the amount of contamination was too high,” she said. She also ruled out natural causes as too many of the Rays had died.

She was concerned the Stingrays kept dying, as there are only about 150 left in the river.

Local communities believed the death was caused by sugar and ethanol-producing factories in Ratchaburi’s Ban Pong district.

An ethanol plant in Ratchaburi admitted that one of its waste water pipes broke, leading to wastewater discharges into the river. It is in the process of fixing it.

It said the incident happened on Sept 30, but the Stingrays started to die a few days before that. However, locals argued the leak started long before the factory claims.

Meanwhile, Prime Minister Prayut Chan-o-cha has ordered officials to find out the cause of the Stingrays deaths, saying the Rays should be conserved as they are an indicator of the condition of the river.

Officials were also instructed to look into the cause of the deaths of fish raised in baskets and take care of the fish farmers, the premier said.

Samut Songkhram governor Kanchat Tansatien said he instructed agencies to collect samples of water and sediment in four locations along the river to find out the cause of the deaths.

The locations which Stingrays regularly inhabit are near Wat Phet Samut Worawihan, Somdet Phra Buddha Loetla Nabhalai Bridge, both in Muang district, Somdet Phra Srisuriyendra Bridge in Amphawa district and Amarin Tharamat Bridge in Bang Khonthi district.

Referring to the mass deaths of Razor Clams in the province, Mr Kanchat said water quality was likely to be the cause. Tests would be conducted.

Source: Bangkok Post

Thailand: VMARC reveals stingray deaths triggered by toxic waste
12th October 2016;

The Veterinary Medical Aquatic animal Research Center (VMARC) revealed that massive Giant Freshwater Stingray (Urogymnus polylepis) deaths in the Mae Khlong River in Samut Songkhram were caused by toxic waste.

VMRAC Director Nantarika Chansue said lab results revealed that it was likely that the fish were killed by toxic waste from factories. She claimed their deaths were not triggered by natural causes.

Dr. Nantarika said even though it was not clear what type of toxic waste was found inside the fish, it was certainly not the kind that could be found in the nature. At least 50 Stingrays were killed in the river.

Pollution Control Department Director General Wijarn Simachaya said authorities will be able to identify the origin of toxic chemicals when more test results are released this Friday.

Legal actions are expected to be taken against responsible factories. Samut Songkhram Governor Kanchat Tansatien has instructed relevant agencies to investigate the cause of Stingray deaths.

Mr. Kanchat also said the recent massive deaths of Razor Clams (Solen sp.) in Don Hoi Lot were caused by algal blooms, not the same toxic waste water that killed the Stingrays. Meanwhile, Prime Minister Prayut Chan-o-cha ordered a quick probe into the problem as it is a direct threat to the ecosystem.

Source: National News Bureau of Thailand

Thailand: Razor Clams dying at Don Hoi Lot; more dead Rays found
By Chularat Saengpassa, 11th October 2016;

Razor Clams (Solen sp.) are dying off in the famous tourist attraction of Don Hoi Lot river delta in Samut Songkhram province, near the same area where dozens of Giant Freshwater Stingrays (Himantura polylepis) were recently found dead.

The number of dead Stingrays found in the Mae Klong River, which runs through Samut Songkhram and nearby Ratchaburi province, now stands at 45, Samut Songkhram’s fisheries chief Utai Singtothong said, as three more carcasses were found yesterday.

Water pollution – the suspected cause of the Stingray deaths – already has taken a toll on the Don Hoi Lot river delta.

“Water has turned red and smelled badly during the past three to four days,” Supap Kongraksa, a village head in Samut Songkhram’s Muang district, said yesterday.

Her team has been inspecting coastal zones after the shocking reports of the Stingray deaths.

“At dawn, I found many Razor Clams climbing up to the muddy surface at Don Hoi Lot. When my team caught them, we found them to be very weak and dying,” she said.

Don Hoi Lot is a famous seaside area that typically has a robust population of Razor Clams. Many tourists travel to Samut Songkhram specifically to visit the area.

“I am now worried that all the Razor Clams here will die,” Supap said.

Bandhit Pansawat, a coordinator for the Self-Managed Samut Songkhram Group, said Blood Cockles (Tegillarca sp.) in the area had also died.

“We also noticed that many small fish had headed out of the Mae Klong River to a connected small canal since September 29,” he said, adding that he was disappointed the authorities had so far said that the water quality was fine.

Utai said yesterday that his agency was in the process of examining samples from the river, as well as water from Don Hoi Lot. “Results should be available soon,” he said.

Last Friday, the Pollution Control Department announced that the amount of dissolved oxygen in Samut Songkhram’s Mae Klong River was sufficient to support life.

Weerakit Joerakate, who works with Kasetsart University’s Samut Songkhram Fisheries Research Station, said his team had collected water, soil and plankton samples along the Mae Klong River yesterday from Samut Songkhram and Ratchaburi provinces.

“We believe we will be able to identify toxic substances, if any are there, within five days,” he said.

Source: The Nation