The Department of Conservation (DoC) is warning people to remain vigilant after an increase in great white shark sightings in the Tauranga area.
Reports of great whites have increased since May 2020 and although an estimate of the number of sharks in the area can't be confirmed, so far six individual great whites have been identified.
Marine biologist Melissa Kellett has been studying sharks in Tauranga for five years. She says the large number of sightings are not only in the Bowentown area of the Tauranga Harbour but also along the coastline.
"Since May 2020 we have continued to receive reports of great white sharks in the area year-round and spread out through the Tauranga district," she says in a DoC statement.
"The size estimates of these sharks have been between 1.5m-3.5m in length indicating they are primarily juveniles and sub-adults."
DoC marine expert Clinton Duffy says sightings of great white sharks in shallower coastal areas and harbours are not unusual.
The smaller individuals appear to remain in New Zealand coastal waters year-round, making regular excursions up and down the coast and out to the edge of the continental shelf.
"Both the west and east coasts of the top half of the North Island are considered a nursery area for great white sharks in New Zealand," he says.
"Adult and sub-adult sharks also inhabit shelf waters, but these larger individuals also make large scale oceanic migrations."
Tracking tagged sharks has revealed movements to tropical and sub-tropical regions like the eastern coast of Australia, Coral Sea, New Caledonia, Vanuatu and Tonga during late summer - early winter for around six months before returning the following year.
"It is now recognised that we have a shared population of great white sharks with eastern Australia, and we are working on an updated population estimate."
Great white sharks are present around the New Zealand coastline all year round, but most encounters between people and sharks happen between December and May as more people head to the beach and the sharks return to New Zealand to feed in coastal waters.
It is common for great whites to develop preferences for certain sites and return regularly and Duffy says if you spot a great white exit the water quickly and calmly and report the sighting to DoC.
"Sharks are predatory animals but do not normally perceive humans as prey and most encounters with white sharks do not result in the shark biting the human," he says.
"If you are visiting the ocean you need to be a little bit vigilant and aware of what's happening around you and swim where there are surf lifesaving patrols, and don't swim or dive alone.
"If you are heading out on the water, exercise caution and avoid swimming in the main channels where there are a lot of birds diving, or berleying from kayaks and jet skis when fishing."
Great white sharks are protected under the Wildlife Act 1953. This means it is illegal to hunt, kill or otherwise harm them. It's not illegal to accidentally catch a white shark but it must be released without causing it further harm, and it is a legal requirement to report the capture.
DoC ask the public to report all sightings, captures or strandings to DOC via sharks@doc.govt.nz or to 0800 DOC HOT (0800 362 468).
