Researchers and local iwi looking into whether increased reports of great whites around Bay of Plenty could be linked to warming oceans

Front on view of a great white shark approaching  camera in murky blue-green waterA great white shark in New Zealand’s Bay of Plenty region. Scientists are investigating increased sightings of the predator in the area. Photograph: Phil Ross

Great white shark sightings are increasing in one of New Zealand’s most popular coastal holiday spots, with a team of experts assembling to find out what is behind the rise.

The population in the Bay of Plenty region, on the North Island’s east coast, booms over summer as holidaymakers flock to the area’s beautiful beaches. But visitors have become increasingly fearful over what appears to be more frequent visits from great white sharks during summer.

The country’s most recent fatal great white shark attack occurred in the region’s north, in January 2021. Since then, there have been a number of sightings, and a lucky escape when surfers at Mount Maunganui beach narrowly avoided a “3.5m monster”.

Now a project involving scientists, shark experts, conservation specialists and the local iwi (tribe) will seek to understand the change in the species’ growing presence and activity in the area.

University of Waikato marine biologist Phil Ross, who is spearheading the project, said the team hoped to find out if there were actually more sharks or if an increase in people in the water had led to more sightings. The team was also looking at what role warming oceans could be playing and whether the animal’s habits or migration patterns were changing.

“It’s almost like a who’s who in the zoo: do we end up with a local population that stays here permanently, or do they stay for a season and then go somewhere else, or are we continually seeing turnover of different sharks coming through the area?” Ross said.

The team is still finalising the details of the project, set to begin in summer, but there are a range of methods that can be employed to monitor the sharks, including installing a GoPro camera on the seafloor near a pot of bait – a common tool to conduct fish surveys, Ross said.

“We’ve been using it around here for years, and we’ve started to pick up these great white sharks coming in to have a nosy.”

Ross said two of the region’s hapū (sub-tribes) were collaborating with the scientists to build up a timeline of the sharks’ habits.

“They have a lot of knowledge about the harbour … we don’t have any data going back past a decade or a couple of decades but oral history could potentially tell us about how things have changed over a much longer timescale.”

Local fishers, boaties, surfers and swimmers can also become useful citizen scientists, and will be able to upload sightings, photos and videos to a specially designed portal for the project.

Part of the project’s aims are to help the community better appreciate and understand the sharks, while keeping them safe in the water.

“Your toaster is more dangerous and more likely to hurt you than a shark,” Ross said. “They have always been there and are not something you need to be constantly afraid of.

“But if you can see there is an area where fish are feeding or birds, that’s not the place to go for a swim.”