Hong Kong  - Shark nets and pollution have been blamed for the death of 16 white dolphins that have been spotted in and around Hong Kong so far this year, a media report said Thursday.

Experts said the number of dead dolphins is the highest ever recorded, but they also think the true death toll could be higher, the South China Morning Post newspaper said.

Five of the dolphins, which were all found between January and July, were discovered in Hong Kong waters, while three were located off Macau and eight in the Pearl River close to Hong Kong.

Chen Xi, deputy technology chief of the Pearl River Estuary Chinese White Dolphin National Nature Reserve, said a preliminary assessment indicated many dolphins were trapped in shark nets along the coastline, while pollution may have also been responsible.

"Some dolphins' intestines were found filled with parasites. We also found some dead dolphins to be thinner than others," Chen said.

Hong Kong Dolphin Conservation Society chairman Samuel Hung Ka-yiu said the death toll in the Pearl River estuary was probably higher. He estimated there were about 1,500 dolphins in and around Hong Kong.

Hung added that while pollution might not be the immediate cause of death it would weaken dolphins' immune system and called on China to introduce measures to reduce pollution in the dolphins' habitat. (dpa)