Early February 2019, Charlie Huveneers, marine ecologist from Australia’s Flinders University, was preparing to embark on a week-long scientific expedition in South Australian waters around the Neptune Islands with his colleagues.

The islands, near the opening of Spencer Gulf, about 230 kilometres from the state capital Adelaide, are a popular tourist destination where people swim – from the safety of cages – with the feared great white shark (Carcharodon carcharias).

On such expeditions, the researchers push off each day at dawn in a chartered boat loaded with equipment. Diving into the cool ocean depths, they take samples from sharks, study their behaviour, and tag them to understand their movements and residency patterns.

The invigorated but weary divers return after dark, then beaver until midnight to enter the data they’ve collected. That’s one of their shorter trips; some can last a month.

“It’s not as glamorous as it looks in the documentaries,” says Huveneers in his French-Belgian accent as he squeezes in a chat before setting off. “It’s as exciting as the documentaries, but it’s hard work.”

Tanned and athletic, 38-year-old Huveneers comes across as candid, but a little guarded. It turns out he walks a precarious line between people with an intense fear of the marine creatures and those vehement about their protection.

“Some people feel very strongly about some topics, and sharks is one of them,” he says.

His colleague and former PhD supervisor Rob Harcourt, from Macquarie University in Sydney, agrees. “People are passionate from both sides of the spectrum,” he notes. “And Charlie has been right in the thick of it.”

Huveneers didn’t know what he was getting into when he started in the field.

He has been driven by curiosity about sharks since age 12. When pondering which animal to present for a school project, his mum had handed him a book on them.

“I was stunned that half of the book was emphasising how little we know about sharks,” he explains. “And that’s what drew my interest.”

Now an internationally acclaimed expert on cartilaginous fishes, Huveneers strives to raise awareness about the misunderstood predators.

He’s come a long way since being awarded PhD about 15 years ago, says Harcourt – who refers to him as his “academic son”.

“He’s gone from being a wildly passionate and enthusiastic, very, very European young student into a very mature, passionate but quite wise adult,” he notes.

For his doctorate, Huveneers researched the effects of extensive fishing on wobbegongs, carpet sharks from the family Orectolobidae, and a popular component of fish and chips in many parts of Australia.

“There were concerns that commercial fishing might have started to impact the population, because it looked like wobbies had dropped in numbers,” he recalls.

He found that because they only produce a litter every three years and their offspring take many years to mature, “wobbies” were indeed vulnerable to overfishing.

As a result the government of the state of New South Wales (NSW) imposed new regulations to restrict harvesting. The species is no longer considered at risk of extinction.

Coincidentally, Huveneers discovered that the two species of wobbegong identified in NSW waters were in fact three.

It was not an unusual outcome. The standard reference for the fish, Sharks and Rays of Australia by Peter Last and John Stevens, increased the number of species listed by 30% between editions in 1994 and 2009.

Currently, more than 500 shark species are known. They range in size from the 22-centimetre pygmy shark (Euprotomicrus bispinatus) to the whale shark (Rhincodon), which reaches up to 20 metres. Huveneers says there are still more waiting to be found.

Just recently, he notes, a colleague described a new species based on three specimens recovered from Western Central Pacific waters. A type of whaler shark, it was formally named Carcharhinus obsolerus but may have become extinct before the process was completed.

Having said that, Huveneers adds, there is much more research and interest in sharks now than, say, 20 years ago.

“Now we actually have the Oceania Chondrichthyan Society – a professional society that encompasses all the oceanic pacific region,” he explains. “So we’ve come a long way.”

Huveneers has made a major contribution to this research effort. After his PhD, he helped Harcourt set up the Integrated Marine Observing System (IMOS), an acoustic network that enables researchers to track everything from jellyfish to white sharks.

A partnership between several universities and marine organisations, IMOS is supported by the Australian Government’s National Collaborative Research Infrastructure Strategy (NCRIS).

It provides infrastructure, including floats, deep water moorings and satellite remote sensing – facilities that systematically observe Australia’s marine environment, biological and oceanographic processes. The data are shared with national marine and climate scientists and international collaborators using the Australian Ocean Data Network (AODN).

Huveneers is now deputy leader of the South Australian IMOS node, and chair of the Animal Tracking Facility’s data committee.

How does he juggle all this with his personal life?

“I’ve been married about five years,” he smiles, and admits that the work-life balance is sometimes difficult to manage. He recognises, however, how critical it is to take time off. His wife Alison does not work in the same area but often joins field trips and helps with the research.

Harcourt joined them on a scientific expedition last November. “His wife is fantastic. They’re a dynamic young couple,” he laughs.

In his spare time, Huveneers enjoys surfing – the beach is just a six-minute walk from his home.

Every year in Australia, shark attacks, often on surfers, attract huge amounts of media attention. He, however, has no fear of taking his board into the waves.

An attack is a “low probability” event, he says, but “the perceived risk from it is completely biased because it has high consequence”.

Public fear of attacks led him to investigate the efficacy of personal shark deterrents for surfers – finding most are not as effective as manufacturers claim.

He’s also discovered that great white sharks use the sun as a predatory strategy, positioning it directly behind them when approaching prey. This could yield further insights for avoiding shark attacks.

On its latest expedition his team conducted “bite tests” for new diving suit material designed to be resistant to perforation by shark teeth.

Above all, Huveneers is energised by new discoveries, being able to shed light on shark ecology, their behaviours, and how they might have evolved.

He swims freely with them on most research expeditions. With experience, he says, you learn what’s safe or not – such as getting a feel for environmental variables like visibility, the time of day, and whether the sharks have fed recently.

“Most species in the right context are completely safe,” he says, although emphasising the need to treat the animals with respect.

Respect, however, only goes so far. When dealing with great whites, he and his colleagues still take the precaution of using a diver cage.

One reason the research is so important is that sharks are a diverse group with vastly different reproductive rates, habitats and morphology. Therefore, Huveneers stresses, you can’t generalise about their sustainability across species.

This has implications for understanding ecologically sustainable levels of fishing and other commercial activities, including cage diving.

Assessing this is one of his goals in working with great white sharks. The growing wildlife tourism industry has come under scrutiny by organisations concerned with shark welfare who assert that cage diving should not be allowed at all because it interferes with the animals’ behaviour patterns.

By investigating how the activity affects white sharks’ residency and movements, with potential impacts on their fitness, Huveneers’ work will help inform public perception and industry regulations.

“I’d like to be able to contribute to increased knowledge of these animals in a way that will make a difference,” says Huveneers, before heading off once more to the waiting research vessel.