Several areas of Ha Long Bay, Quang Ninh Province, are seriously polluted. A test conducted by the bay's management board in June revealed that water near the shore contained excessive quantities of oil, although 43 other locations across the bay were not polluted.
The ports of Nam Cau Trang and Ha Khanh had the highest oil pollution levels, far above the legal limit.
Oil was also seen floating in the water of Bai Chay Tourism Port and other sites where tourist boats anchor, like Vung Dang, Lan Be and Ben Doan.
Tourist boats and cargo ships accounted for much of the pollution, said Le Lam Tuan, chief of the board's Environment Management Division.
"More than 520 tourist boats are operating in Ha Long Bay, but most are small, with engine capacity less than 220 KW. Only 20 per cent of them are equipped with standard waste treatment systems," he said.
Cargo ships which anchored in the bay and illegally discharged water mixed with oil were also at fault, he said.
Oil pollution in sea water can cause serious damage to marine life, Ha The Tien of Viet Long Maritime Technical Service Joint Stock Company told thiennhien.net online newspaper. A seemingly small amount of oil, such as 0.1mg, can kill small creatures which provide food for fish and shrimp. When oil spreads on the water surface, it reduces the amount of available oxygen – bringing death to marine organisms.
According to Tuan, inspectors could not easily crack down on boats that emptied waste water mixed with oil into the water, as oil spreads quickly across the surface, making it difficult to trace.
Currently, no boat owners have been caught red-handed discharging oil into the sea.
To solve the problem, the management board has asked owners of tourist boats to install oil waste filters. The board also proposed implementing regular checks on boats to ensure the elimination of worn-out vessels.
According to Tuan, the provincial authority plans to merge Nam Cau Trang Port with Ha Khanh Port to reduce the oil pollution around the docks. The merger is expected to be complete by 2013.
The board also asked cargo ships to move to Cam Pha Port to load and unload goods instead of anchoring in the bay as a means of preventing pollution, he said.