SHARK SPECIES
The species of shark that attacked, and killed, a woman off Waihı¯ beach may never be known, says one shark expert.
A woman, believed to be in her 20s, was swimming at the Bowentown end of Waihı¯ Beach when she was fatally injured on Thursday.
However, one shark expert says it could be hard to identify what type of shark was involved, despite at least four sightings of great white sharks in the attack area before Christmas.
Department of Conservation shark biologist, Clinton Duffy, said in most cases involving a fatality the species of an attacking shark is never positively identified.
‘‘There simply isn’t enough information to identify the shark, there’s no eyewitness descriptions or there’s not enough physical evidence to be used to identify the shark,’’ he said.
Duff said great whites were seen fairly regularly in the Bay of Plenty with fishermen reporting four sightings in the Bowentown channel before Christmas.
While most of them were small, around 2.5 metres or less, there was one larger great white, around three metres long, which had been seen in the Bowentown channel.
‘‘White sharks, because they feed on sea mammals particularly seals, they are potentially more prone to attacking human beings.’’
But Duffy said there was also a number of other shark species in the Bay of Plenty over summer.
‘‘At this time of the year you get quite a large number of Bronze Whalers moving into shallow coastal water including inlets and harbours and beaches around the upper North Island.’’
Others included hammer head and thresher sharks, which Duffy said neither typically present risk to human beings unless people have caught them and are handling them.
Other sharks like mako and blue could also get quite close to shore at this time of year and there have been previous reports of tiger sharks in the Bay of Plenty over summer.
While sevengill sharks are more likely to arrive in winter they also can’t be ruled out of making an appearance.
Duff denied speculation that warmer summers brought more sharks closer to shore and said there were no more sharks this year than any other year.
‘‘They come in every year, and what may be happening is their distributions might be changing due to changes in their prey, but we have a very poor understanding of that.’’
He said sharks came to shore to hunt schooling fish like snapper, trevally and kahawai, small sharks and stingray.
Duffy said sharks weren’t generally interested in humans in the water. But if you did encounter a shark, the main thing was not to panic and not to make yourself look like injured or potential prey.
‘‘If you don’t know anything about shark behaviour, you should just get out of the water as quickly and quietly as you can. If you splash around, and yell and scream there is a good chance the shark could think you are injured and incapacitated and therefore easy prey.
‘‘Any shark over 1.8 metres long should be considered potentially dangerous because at that size they are obviously capable of inflicting serious injury if they bite you.’’
Duffy also suggests people avoid swimming near channels that run in deep water close to shore which large sharks could use to access shallow water easier.
As horrific as shark attacks were, there were a rare event so there was not necessarily a heightened chance of a shark attack now.
‘‘The risk of a shark attack now is no higher than it has ever been and New Zealand has one of the lowest shark attack rates anywhere in the world but obviously people have to exercise caution along that area.
‘‘There is no way of knowing how long any particular species of shark will remain in an area.’’