The large volume of polluted flood water being released into the Gulf of Thailand could greatly affect marine life, Thai academics warned.

The Nation daily newspaper reported on Tuesday that at a marine scientists' seminar, held on Monday, at Chulalongkorn University ( CU), 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.

The country's worst floods, caused by heavy monsoon and overflow from several dams in upper part of the country, in nearly 60 years has claimed more than 500 lives and affected about 10 million people since mid July. The flood water has been drained from the upper part of the country through Bangkok to the Gulf of Thailand.

The seawater at a 5 kilometres radius from the coast and 15 kilometre-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.

This could affect the Gulf even more severely than the tsunami that hit southern Thailand in 2004 and the country's great flood in 1983.

Meanwhile, 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.