He said the previous three summers had been La Nina – a climate pattern bringing prominent easterly winds and warmer water – and the sharks had been “really apparent”.
That had been a bit unexpected because the conditions should have meant less food around for them.
This was predicted to create “lots of upwelling and food productivity”, meaning “greater fish life” and more food for the sharks.
“Māori legends say east is least, like when the wind is blowing east the fishing is the least … so west is best.
“It will be interesting to see if La Nina, which bought us warm water — which is very important to baby sharks that can’t regulate their body temperature — if that was a major driver or is it food, and the habitat.
“Basically, there is a lot of unknown in the ocean.”
Great White App
Last summer Elliott’s interactive Great White App allowed the public to track four satellite-tagged sharks, most famously 2.75m female Daisy, as they moved around, often in the Bay of Plenty.
Elliott said thanks to public sponsorship he had funding for new trackers but had not yet tagged a new cast of characters for the app, with waters warming later due to El Nino.
Like all fish species, the sharks tended to go offshore during winter and were not likely to return until coastal water temperatures reached about 20C.
“When reports of great whites become more common, new tagging efforts will be made.”
He said one of the biggest takeaways from last summer’s tracking was seeing sharks such as Daisy swimming “right in front of the surf club” during the busy school holidays and “nothing happened”.
“[It] is like ripping off the Band-Aid and looking under the bed and realising the boogeyman isn’t there, you know, it’s just, it’s just a fish.”
The wider research project aimed to better understand the species’ breeding grounds and population.
Another takeaway was seeing how “highly mobile” the tracked sharks were, moving all around the coasts.
Elliott said it suggested the Waihī area was not “shark town” as it may have seemed, although Tauranga Harbour was an important nursery area for great whites.
“It’s common for great whites to develop preferences for certain sites and return regularly, so although we can’t predict what sightings will occur this summer, people should expect to see great white sharks, among others.
“We also appreciate being notified promptly if anyone comes across a dead white shark.
“Both types of information help us better understand the distribution of the species, particularly differences between juveniles and adults.
“Access to dead specimens gives us a chance to study things such as their diet, age and growth, reproduction and threats.”
Staying safe in the water
To keep yourself safe from sharks, avoid swimming or diving:
at night
near seal colonies
near large schools of fish
in areas where marine life is actively feeding
in areas where people are fishing or discarding fish remains