One of Hong Kong's main tourist attractions, the sea mammal has seen its numbers drop by half between 2003 and 2011. Environmental organisations launch an appeal to raise awareness in government circles and among residents.

Hong Kong (AsiaNews) - The Hong Kong Dolphin Conservation Society, which fights to protect endangered species, has released data for the pink dolphins. Estimated at 158 in 2003, the number of the rare mammal stood at 78 in 2011, a drop of about 50 per cent in eight years. The dolphins are a popular local tourist attraction.

An image provided by the Society shows pink dolphins playing in waters off Lantau, Hong Kong on June 7, 2011. Two weeks ago, a tour guide from Hong Kong Dolphinwatch spotted a group of pink dolphins helping a grieving mother support the body of her dead calf above the water in an attempt to revive it. The scene, captured on video and widely shared on Facebook, has raised fresh concerns among local environmentalists about the dwindling population.

"It is up to the government and every Hong Kong citizen to stand up for dolphins," said Samuel Hung, chairman of the society. "We risk losing them unless we all take action."

Shipping and habitat destruction are the greatest threat to the species. Pollution is another problem. "We're 99 per cent certain the calf died from toxins in the mother's milk, accumulated from polluted seawater," said Hong Kong Dolphinwatch spokeswoman Janet Walker.

Fewer than 2,500 of the mammals survive in the Pearl River Delta, the body of water between Macau and Hong Kong, with the majority found in Chinese waters and the rest in Hong Kong.

Meanwhile, an unprecedented number of dolphin beachings continues to baffle scientists. Some experts believe the latter may be caused by naval sonar exercises.

The dolphins, a population of the Indo-Pacific humpback dolphin species, are listed as "near-threatened" by the International Union for Conservation of Nature.

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