A spike of shark sightings over the past two weeks may be due to the El Niño climate shift and has prompted reminders for swimmers to take caution.
Lifeguards recorded more than 40 first-hand sightings of sharks across two regions in the past fortnight, Surf Life Saving said on Tuesday.
And while lifeguards were used to sharing the water with sharks and most of those seen were not big enough to cause alarm, Surf Lifesaving eastern manager Chaz Gibbons-Campbell warned people to be cautious.
“In the past two weeks we’ve had 42 sightings across Coromandel and Bay of Plenty. That’s from lifeguards seeing sharks swimming by, and most of them are on the small size range, so sort of under a metre and a half.”
A shark snapped metres from the beach north of Napier, on Tuesday. Photo: Supplied/ Timothy James Carrington
Marine scientist Riley Elliott told RNZ the El Nino climate shift meant warm, fish-rich waters were just now coming into shore, and with it, more sharks.
“This summer is quite different to last summer in that it’s cooler water, the ocean’s a little bit slower behind in its productivity because of the shift to El Nino.
“We are starting to see that warm productive water come in, more and more fish coming in closer to shore, and with that, shark sightings.”
Dr Elliot said it was worth nothing that while warmer, productive water was more inviting to sharks, there were also more people around beaches through summer to see them.
Hastings man Timothy James Carrington got some close snapshots of a shark he estimated was about 2m long, and only about 2m from the beach at Whirinaki, north of Napier, on Tuesday.
He posted the photos to an online community group to warn people to be careful.
“It was in very close. I walked down the beach to tell a dog owner that was throwing sticks into sea [for his dog] ...that he was throwing the stick further out than shark was.”
Shown the photographs, Clinton Duffy from DoC’s Marine Species Team confirmed the sighting was a bronze whaler (Carcharhinus brachyurus).
“Although potentially dangerous if stimulated by struggling fish or fish blood they present little risk to water users,” Duffy said. “They generally ignore or avoid people in the water but can become aggressive to spearfishing when attempting to steal their catches.”
“It is very common to individuals and large groups of this species close to shore around the North Island and occasionally the upper South Island at this time of year.”
He said the species reach a maximum reported length of 3m and in calm conditions will enter water shallower than their body chasing fish.
Gibbons-Campbell saideven though the vast majority of sharks likely to be encountered at the beach were harmless, people should take safety precautions to keep safe.
“Don’t swim where people are fishing ... and avoid swimming at dawn and dusk,” when sharks are feeding, he said.
And, “around fishing ... make sure that you are disposing of your fish carcasses appropriately, by not dumping them in the ocean.”
Last week marine scientist Riley Elliott warned the El Nino climate shift could bring more cool and fish-rich waters to New Zealand’s coastline, and draw out more sharks.
Duffy told RNZ the best way to stay safe if you spotted a shark was to get out of the water as quickly and as quietly as possible.
A teenager was killed in a shark attack late in December off South Australia’s coast. Several shark attacks had also already been reported in New Zealand waters this summer, including on the Wairarapa coast and in knee-deep water in a Southland estuary.
