Cultural treasures hidden beneath the waves of the South China Sea are being threatened by illegal plunderers and the operations of the modern fishing industry, experts have warned.

Speaking at the 15th General Assembly of the International Council on Monuments and Sites (ICOMOS) which concluded on Friday in Xi'an, capital of Shaanxi Province, Zhang Wei, director of the China National Museum's Submarine Archaeology Research Centre, said unscrupulous fishermen are targeting the country's underwater treasures.

Historically, the South China Sea has been a popular trade route. Dubbed the ancient marine Silk Road, many vessels sank in the sea's waters taking their valuable cargo with them to the bottom.

In the latest case, local fishermen discovered a Qing Dynasty (1644-1911) wreck in the South China Sea in June.

Attempts to hook booty from the boat caused serious damage to the archaeologically important wreck.

There has also been a sharp rise in the number of China's fishing boats.

Trawlers dragging their nets along the bottom of the sea can damage wrecks. When relics are brought to the surface in a boat's nets, some are illegally kept and sold, while others are thrown back into the sea by fishermen not recognizing what they have caught, Zhang said.

Development in coastal areas, such as the construction of harbours and coastal defences also threaten underwater cultural heritage, the director added.

Experts say endangered cultural heritage has not attracted enough public attention, and advocate the listing of the protection of heritage as part of the country's overall ocean development strategy.

Those attending the present international cultural heritage meeting suggested China should establish a protection and monitoring network for its underwater cultural heritage.

"China should join the Joint Pledge of Submarine Cultural Heritage as soon as possible and seek international co-operation to stop the robbery of underwater relics," said Zhang.

Editor: Wing