SHARK nets being installed at three beaches could pose a danger to other marine life, but this had to be balanced against the risk from the sharks, Jo Ruxton of the World Wide Fund for Nature said.
The 150-kilogram nets are being installed at Clear Water Bay Second Beach, Silverstrand Beach in Sai Kung and Kadoorie Beach in Tuen Mun, after two swimmers were killed by sharks in Sai Kung last summer.
But dolphins and other marine animals also frequent those areas and Ms Ruxton, a senior conservation officer, said shark nets used overseas had entangled dolphins, turtles and in one case a whale.
'I wouldn't want to say [the World Wide Fund for Nature] is against using the nets - we're not - but there is always a concern there,'' she said.
Dolphins swimming down the Pearl River have been spotted frequently feeding between north Lantau and Tuen Mun.
Other dolphins in transit from elsewhere, such as the bottlenose dolphin, have been seen around Sai Kung.
Ms Ruxton said they would wait and see what happened, but they would be concerned if dolphins and other animals were becoming entangled in the nets, which are made of a strong nylon.
But she added: ''There's always a concern there, but how do you compare it to the loss of human life? You can't.'' When two divers from the South China Morning Post inspected the nets, they found no evidence of aquatic life caught in them. However, their effectiveness is only likely to be measured in June when warm currents attract tuna into the waters around Hong Kong. The tuna in their turn attract the two most dangerous fish known to man - the great white and tiger sharks.