The mass surfacing and and subsequent dying of aquatic life, particularly lobsters prawns and fish, in Oya River, Dalat that went viral on social media could have been caused by many factors, including poisoning.
Nanoplankton specialist Musa Musbah said 20 to 30 years ago, such phenomenon occurred not only in Dalat river but also in other rivers in Sarawak including in Niah and Sibuti areas in Miri, with varying degrees.
He was asked to comment on the so-called ‘drunken phenomenon’ of aquatic life in Oya River, which drew many comments on his Facebook page.
Musa reminded those who doubted the safety of such prawns or fish sold in the market to temporarily avoid eating them until the authorities come up with their findings and give assurance that whatever is caught from the river is safe to consume.
He did not deny that there might be some individuals who used poison to catch fish and prawns due to ignorance on its impact on health, while there might be others who did it for quick profit.
Meanwhile, Natural Resources and Environment Minister Dato Sri Wan Junaidi Tuanku Jaafar was reported in the local media as saying that the Department of Environment (DoE) would investigate and study the causes of the phenomenon.
Officers suspect that the high temperatures caused hypoxia in the pond, killing the shrimp and fish.
Photos: Kritsada Mueanhawong
Thailand: One tonne of dead fish found in Phuket park
By Kritsada Mueanhawong, 22nd April 2016;
A large number of fish and shrimp have died in a pond in Suan Luang Park in Phuket Town from either a rise in temperature or polluted water, confirmed officials.
“The local community around the park has complained about the dead fish,” said Phuket City Deputy Mayor Thavorn Jirapattanasophon. “About one tonne of dead fish have been found since Wednesday, including Java Barb (Barbonymus gonionotus), Catfish (Siluriformes), Snakehead (F. Channidae), Nile Tilapia (Oreochromis niloticus), shrimp and numerous others.”
Mayor Thavorn headed the clean-up project, directing officials to collect water samples from the pond, so the water quality could be tested.
“Our initial tests suggest that the water is safe,” said Mayor Thavorn. “It is most likely that due to the high water temperatures, there is a lack of oxygen in the pond, which is causing this phenomenon.”
Similar incidents have taken place several times in the past.
On March 23, it was reported that Krabi officials had to bury about five tonnes of dead fish that died under similar conditions (story here).
Malaysia: Pollution suspected cause of dead fish, prawns in Sarawak River
10th August 2014;
People living along the Sarawak River here have alerted the authorities of dead fish and prawns found floating along certain sections of the river yesterday.
A check conducted near the Tun Salahuddin toll bridge in Pending found a number of dead fish floating in the water, which appeared to be covered in a thin film of oil, as well as dead prawns washed up on the bank.
A local resident commented that the sudden presence of the dead fish and prawns could be an indication of pollution in the river, but did not discount other factors contributing to the deaths.
Meanwhile, a Facebook posting by Balai Polis Sentral Kuching (Central police station) showed that several of its personnel were dispatched to monitor sections of the Kuching Waterfront after members of the public reported similar cases of dead fish and prawns floating there.
The posting also mentioned that the incident could have been caused by pollution in the river.
Kuching City North Commission (DBKU) Datuk Bandar Datuk Abang Abdul Wahap Julai said the incident could have happened due to contamination caused by chemical waste dumped into the river by unscrupulous people.
He advised the people, especially those living in the villages along the river, against consuming the dead fish or prawns.
Natural Resources and Environment Board (NREB) controller Peter Sawal said investigations on the matter would be conducted.
“So far, we have not received any reports, but we will look into the matter,” he said when contacted yesterday.
Oriental River Prawn (Macrobrachium nipponense) Tampines, 12th May 2013
There is a thriving population of Oriental River Prawn, a non-native freshwater crustacean, in Tampines Quarry Lake. Several were collected as juveniles and subsequently raised to maturity in captive conditions. This adult survived in an aquarium for some time, but died from unknown causes after being transferred to another tank.