Cleaner water may be drawing sharks to HK
Improving water quality could explain why more sharks have been spotted in Hong Kong's waters this summer than at any time since 1996, according to a marine expert.
'More than 10 years ago the Hong Kong government began to clean up the pollution sources along the east coast of the New Territories,' said Suzanne Gendron, head of zoological operations at Ocean Park.
'Water quality has steadily improved over the years. In addition, the artificial reefs deployed in the eastern waters have successfully attracted fish, the small sharks' main diet. The small sharks sighted within Hong Kong waters may have been attracted by the increasing numbers of fish.'
The sightings have resulted in the temporary closure of some beaches and warnings to the public to keep out of the water, including an alert issued yesterday when a metre-long shark was sighted in Hoi Ha Wan Marine Park.
This has led to suggestions that the Leisure and Cultural Services Department, which manages beaches, is overreacting because species found in Hong Kong waters are not normally dangerous to man.
Last month the department issued more than 20 press releases about shark sightings at Hoi Ha Wan in Sai Kung, and on July 11 it closed Stanley main beach after the carcass of a juvenile shark was found entangled in a shark-prevention net.
The dead shark was believed to be one of three juveniles - measuring 60cm to a metre long - spotted near Hoi Ha Wan earlier.
Shark warnings were in force at 10 beaches on the south of Hong Kong Island on July 12.
Marine experts identified the dead shark as a blacktip reef shark, a species not dangerous to man.
'These small sharks are primarily fish and invertebrate feeders and only show aggression when cornered or [hooked],' Ms Gendron said.
Another expert, Andy Cornish, conservation director of WWF, said this species was not dangerous even when fully grown. 'I have swum with many,' Dr Cornish said. But he added they had been known to bite people's ankles wading in shallow water where they liked to hunt.
Dr Cornish said it was unusual to have repeated and reliable sightings in the same place over many weeks.
A spokesman for the Agriculture, Fisheries and Conservation Department confirmed there had not been so many shark sightings since 1996.
Dr Cornish said it was also possible there was a link with the exceptionally hot weather. Last month was the hottest July since 1967.
Asked if the government had overreacted by closing the beaches, Dr Cornish said: 'It should not be necessary to close a beach with a shark net, providing the shark net is properly maintained and any shark seen is outside the net.'
