Vietnam's coastal region of West Bac Bo (Tonkin) Gulf, adjacent to China and other Asian countries, suffers from transboundary environmental pollution and joint efforts are being urged to tackle this problem.

Researcher Luu Van Dieu, from the Institute of Marine Environment and Resources, said cross-border rivers including the Red, Ma and Ca rivers are major sources of pollutants poured into the gulf.

According to a country report by United Nations Environment Programme, Vietnam 's marine pollution issue dates back to 2004. Every year since then, the Red River alone brings to the gulf 232,000 tonnes of biochemical oxygen demand (BOD), 353,000 tonnes of chemical oxygen demand (COD), 31,000 tonnes of nitrogen, over 7,000 tonnes of phosphate, over 4,000 tonnes of heavy metals, 210 tonnes of fertiliser and about 13,000 tonnes of oil.

BOD and COD are two different ways of measuring how much oxygen will be depleted from the water. In both cases the oxygen-consuming substances are mainly of organic origin.

Waste from the river made up 95 percent of the total pollutants discharged from this part of territory where the river runs through, the report said.

Dieu said that the stream flowing into the gulf led the transboundary pollution not just in the countries adjacent to the gulf and offshore area. There is also evidence of oil spills, marine waste and pollutants.

It is reported that in the last 25 years, about 140 oil spills occurred in the western region of the gulf. In late January and early February of 2007, oil spills were seen in coastal areas of the central provinces Ha Tinh and Quang Binh before spreading to the south. The accumulative collected oil was more than 1,700 tonnes.

"Up to 77 percent of oil spills in Vietnam 's waters have yet to be dealt with, or properly compensated," Dieu said, adding that it is due to poor management and insufficient legal framework.

Raised awareness and capacity to manage transboundary pollution are necessary, he said.

Domestic and international co-operation among countries and organisations can help minimise the impact of transboundary pollution, he emphasised.

Dr Dinh Van Huy from the institute also said that so far, there are few insightful studies completed on this issue.

Investing in observation and assessing the current situation are necessary first steps, he said, adding that the institute submitted a proposal for requesting funding further research.

More observation stations should be set up along coastal lines and along the upper parts of rivers, facilitating a proper data base for assessment of the current situation and forecast changes in the coastal areas./.