‘We can’t blame sharks for encountering them more’: shark expert

A shark expert believes that the fact that there are more people in the water is the likely reason behind the number of shark sightings this summer.

Swimmers on an east Auckland beach were warned today to be careful after sharks were spotted, and another shark warning is on a west coast beach. Last month, 19-year-old Kaelah Marlow died after she was apparently attacked by a shark on Waihī Beach in the Bay of Plenty.

Marine scientist and shark researcher Riley Elliott said the increase in the number of sightings is not surprising, even though their populations are declining.

He said there are far fewer sharks than before, but many more people go into the water than before.

“So you put all of that into perspective –
“We can’t blame sharks for encountering them more, we can only blame ourselves, we can only educate ourselves, and we can only understand the environments we enter and accept risk if we are to enter them.”

But Elliot said all shark tragedies need to be investigated so that we can learn from our mistakes.

“It must be recognized because we do not want this to continue, it is necessary to learn from them, it is necessary to react to these tragedies.”

Elliott said it is vital to distinguish science from personal observations.

A major international report published in the journal Nature a few weeks ago indicated that the number of sharks around the world has dropped 70 percent in the past 50 years due to an 18-fold increase in fishing pressure, he said.

“That’s an absolute scientific fact, so we only have 30 percent of the world’s sharks left, and that’s a huge decline.”

Elliot said that many reports in the media or from fishermen are personal observations.

“I’m looking at a couple right in front of me saying ‘because we stopped making shark fins, there are sharks everywhere.’ That’s a personal observation.”

Elliot said that doesn’t count as fact or science.

“But when we have a unique tragedy like the unfortunate one in Waihī of a suspected white shark, that stands out as an anomaly that we should investigate because statistically and scientifically great whites in that area have not been common.”

He said great whites were sighted at Bowentown in Tauranga last year and one reportedly bit off a surfer’s board on Pauanui Beach.

At this stage, these are anomalies that are not yet statistically significant, he said.

“But any tragedy is statistically significant in my eyes as a shark biologist.”

Australian shark population

Elliot said Australia should be divided into two distinct areas in terms of shark attacks.

“Western Australia has far fewer shark attacks, but almost all of them are fatal, whereas the east coast of Australia had, I think, 88 in the last 10 years, but a very small proportion of them are fatal.”

He said that on the west coast, mature sharks hunt seals, and their hunting grounds overlap with areas where surfers are.

“There is just a full-blown predatory attack, resulting in deaths because these people are also far from medical help.”

Elliot said there is a much larger population of smaller white sharks off the east coast of Australia because estuaries and shallow-water coastal systems are good nurseries.

“You get a lot of bites, a lot of these young sharks don’t really understand what’s going on yet, their diet changes from fish to mammals, being seals and not us, and they make mistakes.”

Elliot said sharks from eastern Australia are part of New Zealand’s shark population. Most of this country’s shark population hunts around the southern islands.

But he said the sharks that have been seen on the North Island are juveniles.

“They live in our northern ports, they exceed eight feet and change their diet from fish to seals and begin to descend the coasts or begin to migrate.”

Elliot said he is curious and concerned to see if New Zealand ends up with younger sharks, potentially leading to increased encounters.

He said there have been a low number of shark deaths in New Zealand in the last decade.

“So there is nothing to panic about, but it is something that requires investigation for sure.”

He said juvenile great whites have been protected since 2004 and that protection should lead to population growth.

“But we’ve also increased fishery bycatch rates in that time – I think juvenile white shark kills have been 53 in the last eight years, and that’s just what’s reported.”

Elliot said there is very little data on the numbers of sharks, but useful information could be obtained from fisheries if they were forced to better report their catch.

“The bottom line is that unless the government starts allocating money to start investigating these things [and] to make fisheries better report their catches, we don’t have data. “

Elliot said that without that it is impossible to know large white numbers and determine if they have “moved in their habitat and behavior.”