Thailand: More Stingray fish found dead in Mae Klong river
8th October 2016;

More Stingrays (Urogymnus polylepis) were found dead in Mae Klong river yesterday, raising total death of this protected freshwater giant fish species to 16 so far this month.

The new discovery of the three Stingrays were reported to authorities as they were meeting yesterday in Samut Songkram to discuss the mass fish death in cage farming along the Mae Klong river yesterday.

The meeting was chaired by Samut Songkram governor Khanchat Tansathien.

At the meeting the governor has requested the Royal Irrigation Department to cooperate with Vajiralongkorn dam to release more water to drive out polluted water in an effort to prevent further mass death of not only fish in cage farming, but also natural marine lives in the river.

He reportedly complained over delay by relevant agencies, thus hindering prompt action to address the problem.

The governor then ordered officials to work around the clock to resolve the problem.and bring the river back to normal.

Yesterday scientists also collected samples of water from the river for laboratory test to find out actual cause.

Source: Thai PBS

Thailand: Mass fish death in Mae Klong river prompts official investigation
7th October 2016;

The mass death of fish in cage farming and of Stingrays in the Mae Klong river in Samut Songkhram province has prompted an official investigation into the cause and find those who are responsible.

The investigation team led by Samut Sakhon governor and director of the Veterinary Medical Aquatic Animal Research Center (VMAARC) – Chulalongkorn University inspected the river and some fish cage farms along the river yesterday and tested the quality of the water.

After the inspection, the governor Mr Kamchatka Tansatien disclosed that it was likely that the mass death of fish in cage farming and the death of several Stingrays in the river was from water pollution.

He said the water test showed that the biochemical oxygen demand or BOD quantity in the river is low and below standard.

There was also chemical substance in the water which might be the cause of pollution, he said.

Meanwhile officials from the VMAARC also collected samples of the dead Stingray which was not discarded due to its big size for laboratory test.

The quality of water in the river passing the province is now in critical level and provincial authorities will soon assess the situation before giving instruction to cage fish farming in the river.

Since the beginning of this month a dozen Giant Stingrays have died.

Cage fish farmers and residents suspected a factory near the river bank in adjacent Ratchaburi province is responsible.

Source: Thai PBS

These Stingrays are the endangered Giant Freshwater Stingray (Urogymnus polylepis).

A dead Giant Freshwater Stingray that floated from the Mae Klong River to Khlong Bang Khan Taek in Muang district, Samut Songkhram, found on Friday.
Photo: Pattarapong Chatpattarasill

Thailand: Alarm over dead Stingrays in Mae Klong River
By Ploenpete Atthakor, 7th October 2016;

The discovery of 14 dead Giant Freshwater Stingrays (Urogymnus polylepis) in the Mae Klong River in Samut Songkhram has sparked suspicions some factories have discharged polluted water into the western region’s major waterway.

Fourteen dead Stingrays, a threatened species, have been found floating in the river since Sept 29, prompting an inspection that found the water’s condition has deteriorated, with the biochemical oxygen demand (BOD) level now delow acceptable standards.

An investigation has been set up to find the cause.

An environmental protection group in Ratchaburi has filed a complaint against a Ban Pong-based sugar factory, believed to have discharged water into the Mae Klong River.

Rattawut Wallathanaroj, secretary-general of the network for environment protection and corruption, said provincial industrial authorities took samples of water from the factory’s outlet pipe to check for pollutants.

He said the river’s banks are dotted with large industrial plants, some of which may be in breach of environmental regulations.

“It must be investigated if water discharged from these Ratchaburi-based factories is linked to the death of the Stingrays,” said Mr Rattawut, adding he believed there is connection given the location of Samut Songkhram at the river’s end, that makes it a catchment area.

An official at the Ratchaburi Industrial Office said he was still waiting for the result of the tests on the discharge from the sugar factory.

“In fact, the factory does treat the water but regulations state it must store the water for use by farms, not release it into the river,” he said.

The Ratchaburi-based factory was a long way from where the Stingrays were found. At this stage it was not known if the factory was to blame.

“We are working with officials in Samut Songkhram to establish the cause,” said the official, who asked not to be named.

He said it was possible that, given Samut Songkhram’s normally saline water, a sharp rise in the freshwater level as a result of heavy rains in recent weeks may have caused the fish deaths.

“Fish can go into shock in such conditions,” he said.

However, Chavalit Vidthayanon, an ichthyologist, ruled out the suggestion a rise in freshwater levels may be the cause. He blamed it on water pollution from factories.

The Giant Freshwater Stingray is on the IUCN’s red list of threatened species and is highly sensitive to pollution, he said.

“If the freshwater level rises, it can swim to the river mouth and out to sea,” he said.

Source: Bangkok Post

Tentative identifications:

  1. Telkara Glass Perchlet (Ambassis vachellii), Peanut Worm (Sipuncula)
  2. Mangrove Whipray (Himantura walga), Grouper (Epinephelus sp.)
  3. Grouper
  4. Mangrove Whipray
  5. Mangrove Whipray
  6. Green Chromide (Etroplus suratensis)
  7. Green Chromide
  8. Sole (F. Soleidae)
  9. Spotted Scat (Scatophagus argus)
  10. Green Chromide

Reporting from Seletar Dam facing Johor side. Unusually strong pungent smell from the sea got my curiosity as I was riding past this stretch.

Along the shores was a zone of 2 metres with dead horseshoe crabs (F. Limulidae), Mangrove Whiprays (Himantura walga), Flower Crab (Portunus pelagicus), Grouper (Epinephelus sp.), Sand Whiting (Sillago sp.), Green Chromide (Etroplus suratensis), Spotted Scat (Scatophagus argus), Barramundi (Lates calcarifer), Toadfish (F. Batrachoididae), shrimps and huge colonies of marine bristleworms (Polychaeta).

Source: Benjamin Li Facebook

(This is Part 2 of a 3-part photo set)

Tentative identifications:

  1. Grouper (Epinephelus sp.)
  2. Oriental Sole (Brachirus orientalis)
  3. Mangrove Horseshoe Crab (Carcinoscorpius rotundicauda)
  4. Various bristleworms (Polychaeta)
  5. Various bristleworms
  6. Various bristleworms
  7. Crabs and shrimps
  8. Toadfish (F. Batrachoididae)
  9. Mangrove Whipray (Himantura walga)
  10. Green Chromide (Etroplus suratensis)

Reporting from Seletar Dam facing Johor side. Unusually strong pungent smell from the sea got my curiosity as I was riding past this stretch.

Along the shores was a zone of 2 metres with dead horseshoe crabs (F. Limulidae), Mangrove Whiprays (Himantura walga), Flower Crab (Portunus pelagicus), Grouper (Epinephelus sp.), Sand Whiting (Sillago sp.), Green Chromide (Etroplus suratensis), Spotted Scat (Scatophagus argus), Barramundi (Lates calcarifer), Toadfish (F. Batrachoididae), shrimps and huge colonies of marine bristleworms (Polychaeta).

Source: Benjamin Li Facebook

(This is Part 1 of a 3-part photo set)

Mangrove Whipray (Himantura walga)
Pulau Ubin, 3rd December 2009

Blue-spotted Stingray (Neotrygon kuhlii) (?)
Sentosa, 24th May 2008