At a marine scientists’ seminar at Chulalongkorn University (CU), Asst Prof Pramot Sojisuporn from CU’s Physical Oceanography Department, said some 10 billion cubic metres of polluted water would pour into the Gulf over a short period. This would cause the salinity to be dramatically lowered from the Gulf’s normal level of 32 parts-per-thousand (ppt) to just 2 ppt.
The seawater at a 5km radius from the coast and 15km-deep would be like freshwater, affecting the mangrove bio-system and creatures exposed to such conditions for one to two months could be killed, he said.
“Normally, if freshwater pours into the sea and remains for only a week, it won’t extensively affect the area and creatures. But this flood water would affect coastal incubation grounds for shells, as well as the chub, [and] mackerel in Phetchaburi and Samut Sakhon,” he said.
This could affect the Gulf even more severely than the tsunami and the great flood in 1983.
Marine and Coastal Resources Department executive Micmin Jarujinda said his office was setting up 50 spots for water quality testing around the Gulf, which would monitor the salinity and dissolved oxygen levels over the next 10 days.
With the water expected to flow towards the Gulf’s western coast the areas of most worry were Samut Songkhram’s Don Hoi Lot, Phetchaburi, Prachuap Khiri Khan and Chumphon, he said. Bruda whales and Irrawaddy dolphins could be indirectly affected as their food, such as sea catfish and squid, would be reduced.
Thammsak Yeemin from Ramkhamhaeng, said an inspection at Chon Buri’s Koh Khangkao and Koh Sichang showed the salinity level of the “upper sea” was down to 4ptt while the lower sea was at 23ptt. It also found 64-per cent coral bleaching.
The seminar, which will also propose measures to tackle the problem – was told that 40 crabs were seen dying on a 1km stretch of the Samut Songkhram coast, while the seawater had turned black-ish and smelly.
Meanwhile, the Pollution Control Department (PCD)’s Waste and Hazardous Substance Management Bureau director Rangsan Pinthong said the quality of water in Bangkok and Pathum Thani was substandard.
Test results on flood water –especially at people’s homes – in Don Muang, Sai Mai and Lat Phrao districts showed a deteriorated water quality and the lower-than-standard level of dissolved oxygen. However, water on roads was a better quality because it flowed.
Water in Nakhon Sawan, Ayutthaya, Chai Nat and Lop Buri, though, was normal.
He also said there was no report of water contaminated with chemicals and a check of five industrial estates in Ayutthaya and Pathum Thani’s Nava Nakorn Industrial Estate found officials had good control of the flood situation.
Rangsan said the PCD would continue to assess the situation in Lat Krabang and Bang Chan industrial estates regularly. The department would also give advice for rehabilitation after the flood on water quality to related agencies.
Disaster Prevention and Mitigation Department chief Wibul Sanguanpong urged people in flood-hit homes not to use chemicals during the flood and to securely cover containers with chemicals and put them away in case they leak into the water and cause harm or an allergic reaction by some people.
Wibul urged people to split electronic garbage such as batteries from dry trash and keep it away from water. He said people who spot chemical containers, wastewater pools or hazardous garbage underwater should alert officials so they can be disposed of properly.