THE first study of Hongkong's dolphins is nearing completion but conservationists fear it may be too little too late to save their habitat from ruin. The dolphins, coloured pink, grey or white, may be a previously unrecorded species or sub-species of dolphin and have been seen in pods of up to 47 around Lantau Island, particularly to the north where the new airport and a sewage outfall are planned. They feed around the island and have been seen nursing at nearby Brothers Islands. But sediment stirred up by dredging, the dumping of contaminated mud and plans to build a submarine sewage pipe from north Lantau to the Brothers are posing threats. The study, funded by the Territory Development Department and conducted by an expert from the United States, is looking at the effects from the sewage pipe. The Provisional Airport Authority has turned down requests from the World Wide Fund for Nature (WWF) to fund a study on airport impacts. The sewage study, to be ready within the next few weeks, will also identify other areas needing investigation and remedies to help protect the dolphin population from declining or being wiped out. But the WWF's marine conservation officer, Ms Jo Ruxton, fears it will take two to three years for other studies to be completed and longer to be implemented - by which time most of the north Lantau habitat will be destroyed. ''We just don't have that much time,'' she said. ''These could be a new species or sub-species of dolphin - we don't know. But are we going to sit back and let them disappear?'' The dolphins are usually referred to as Indo-Pacific humpbacks. But Ms Ruxton said they lacked a definite hump and did not resemble the humpbacks. ''They should be getting the same attention as the Romer's tree frog,'' she said. ''It amazes me. There are six-foot pink dolphins here and nobody knows about them. And yet for a little tiny brown frog, everybody is up in arms.'' The Jockey Club gave $500,000 in research funds to prevent the thumbnail-sized tree frog, native to Chek Lap Kok, being wiped out by the new airport. Ms Ruxton said it was not known how many dolphins there were, whether they travelled up the Pearl River, or what importance Hongkong played in their feeding and breeding. The dolphins used to be seen mostly north of Lantau but some were now being seen around Discovery Bay near the planned Container Terminal 9. Ms Ruxton said the environment north of Lantau was poor for the mammals, with heavy sediment stirred up by dredging for the airport and North Lantau Expressway, diminishing the food supply. Mammals might also be at risk of contamination from the dumping of toxic mud in the area. The toxins could infect the animals they fed on, but that needed to be confirmed by studies, she said. Over-fishing by local trawlers was another problem because it diminished the food supply. The WWF recently received its first report of dolphins tearing through a net west of Lantau to get to the fish. Usually they keep a distance from fishing boats. ''Obviously their hunger took over their normal reservations,'' Ms Ruxton said.
