Hong Kong's iconic Chinese white dolphins are dwindling fast and fresh evidence show an alarming 60 percent plunge in their numbers in one year due mainly to the construction of the Hong Kong-Zhuhai-Macao Bridge.
World Wide Fund for Nature Hong Kong fears the dolphins will face a graver situation when construction of the airport's third runway starts as it involves reclamation of four times more land than the bridge and as it takes double the time to build.
The group urged the government to designate waters off Tai O as West Lantau Marine Park immediately and lay down a timetable to expand marine protected areas to cover at least 10 percent of Hong Kong waters.
According to the latest annual dolphin monitoring report of the Agriculture, Fisheries and Conservation Department, the number of dolphins in western Hong Kong waters -- from Tuen Mun to Sokos -- is 65 between April 2015 and March 2016. The number stood at 87 the year before.
The dolphins face unprecedented risk, said Samantha Lee, WWF's assistant conservation manager of marine.
Between 2003 and 2015, the number of dolphins found in north Lantau dropped from 102 to 10.
No sightings were reported in northeast Lantau last year, which used to be the cetacean's core habitat. Northwest Lantau posted an 88 per cent plunge in cetacean sightings over the past 13 years.
The percentage of juvenile dolphins also dropped to a historic low in the past 14 years. The green group attributed the shift in habitats to the construction of the bridge and the increased marine traffic in the area.
"Reclamation could bring irreversible detriment to dolphins, as the filling of reclamation pollutes the water, reduces their food supply and affects their health. The frequent sailing of construction ships also interferes with dolphins as they use sonar to navigate through the ocean," Lee said.
The government should designate the waters off Tai O as West Lantau Marine Park, Lee said, as the waters off Tai O and West Lantau are the core habitats now.
Designating the coastal waters as marine park will link current and future marine protection areas in the north and southwest Lantau, forming a network of protection to the remaining prime habitats and travelling corridors of dolphins.
The group also urged the government to lay down a timetable to expand marine protected areas to cover at least 10 percent of Hong Kong waters, compared to the current level of 1.5 percent. Lee said the percentage is tiny compared to the 40 percent coverage of country parks.
"After the waters are designated as marine protection area, developments will be avoided, activities that may have ecological impact like fishing will be controlled and ships will be limited to sail at 10 nautical miles per hour. The marine protection area will have a conservation effect to the species there," she said.
adeline.mak@singtaonewscorp.co= m
