Three hours off the coast of South Australia, in the remote and rugged Neptune Islands, white sharks gather.
These apex predators are drawn to these offshore islands near Port Lincoln by fur seals, thousands of which form breeding colonies in the islands’ rocky coves.
And, in turn, humans are drawn to the Neptunes to dive beneath the waves and see the sharks.
“They’ve got a charisma,” says Andrew Fox, a white shark photographer, researcher and conservationist who operates Rodney Fox Shark Expeditions. “It’s not just the danger factor – they’re hard to get to know and they hold their secrets. We still don’t know a lot of basic biology about white sharks, even though we’re trying really hard with researchers.”
The industry provides near-constant monitoring out in the remote Neptunes, which is a boon for scientists like Lauren Meyer from Flinders University’s Southern Shark Ecology Group.
“Research and cage diving here in South Australia have gone hand in hand for decades,” Meyer says. “Without the tourism industry, we wouldn’t have the support to undertake our research, and in turn, wouldn’t know a fraction of what we do about white sharks.”
Fox is the son of filmmaker and conservationist Rodney Fox, who pioneered shark cage diving here in the 1960s. When Jaws hit the cinemas in 1975, people were suddenly keen to pay money to see white sharks, and they flocked to South Australia to do it.
Today, SA is the only place in the country – and one of just five countries worldwide – where people can dive with white sharks, submersed in cages to get an up-close-and-personal experience.
But the cage-diving industry is really about the sharks, Fox says.
“Part of our mission statement for our whole operation right from the beginning, from my dad’s work back in the last century, was to collaborate with educators, conservationists and researchers to progress the understanding of great white sharks, which are so misrepresented in the media and in the public,” he says.
In the early days, it was film production companies and occasionally large tourist groups who provided a platform for researchers to come out to the Neptunes.
“Nobody gave money for researchers to come and study great white sharks, as a non-commercial species,” Fox explains.
But now, they work directly with tour operators to get logistical support.
In 2001, Fox co-founded the Fox Shark Research Foundation, which has since been working with the CSIRO, SARDI (South Australian Research and Development Institute) and Flinders’ Southern Shark Ecology Group to gather data on sharks.
“By working alongside the cage-diving industry we have built outstanding data sets – we have a 20-year dataset for the number of sharks they see on every cage-diving expedition,” Meyer says. “We have basically teams of observers that are monitoring the sharks nearly every day, year-round.”
Daily monitoring of sharks is part of the current tourism regulations for the two businesses licensed to operate in the Neptunes.
Daily monitoring of sharks is part of the current tourism regulations, she explains, for the two businesses licensed to operate in the Neptunes: Rodney Fox Shark Expeditions and Calypso Star Charters.
“The industry reports exactly how much bait is used, how many sharks were sighted and which ones, as they identify the individual sharks where possible. This data includes how big the shark was, if it was a male or a female, and if it accidentally took any baits. We get all of that information daily.”
These observations are reported to SA’s Department for Environment and Water, as well as to the Southern Shark Ecology Group, led by Professor Charlie Huveneers at Flinders. The results help inform regulations for tour operators.
Early days, early ways
A study into shark residency was what really kicked off the research, Meyer explains, promoted by a boom in the tourism industry around 2007, when tours began operating almost every day.
“Early on, the industry was just a multi-day trip every one to two weeks,” she says. “But as interest in seeing white sharks grew, and the amount of cage diving increased to day trips nearly every day, the residency of white sharks at these islands also increased.”
Although the seal and sea lion colonies at the Neptune Islands are important feeding sites, white sharks are only temporary residents there. After the 2007 tourism boom, a 2011 CSIRO-led paper – co-authored by researchers Barry Bruce and Russell Bradford – found that sharks were sighted around the islands more often, and the duration of their visits also increased.
This research led to tighter regulations on cage-diving operators, limiting the number of days they can take tourists to the islands. For example, regulations that flowed from the initial residency study allowed trips on only 10 out of 14 days – “to give the sharks bit of a break from interacting with the cage-diving industry,” Meyer says.
Recently, that number has been relaxed to 12 out of 14 days, notes Fox.
“It’s quite important that a lot of the research that we do ties back into analysing whether we are having a detrimental effect on the sharks,” Fox says. “The sharks’ welfare comes first.”
A 2013 study led by Huveneers found that cage-diving activities also affected the swimming behaviour of white sharks in the Neptunes; they spent a significant amount of time close to tour boats, though the team couldn’t conclude what flow-on effects this may have at the population level.
A follow-up study in 2018, also led by Huveneers, noted that sharks undertook more high energy burst activities when close to tour operators – for example, to chase a bait – though the overall impact might be small for individual sharks if interactions are infrequent.
The bait is just used to bring the sharks within view of the cage divers, not to feed them – the bait is removed before the sharks can catch it.
An area of research concern is the sharks’ feeding behaviours, especially since the tour operators use bait (large pieces of southern bluefin tuna guts and gills) and berley (minced-up tuna) to attract sharks.
“The bait is just used to bring the sharks within view of the cage divers, not to feed them – the bait is removed before the sharks can catch it,” Meyer explains. “We wanted to understand, if the sharks are sticking around longer, is interacting with the cage-diving industry changing their diet? As the sharks do occasionally catch the bait, is this impacting their diet and nutrition? Or, if they spend all of their time around the cage, are they not foraging naturally?”
A 2019 study led by Meyer found that this was not the case – cage diving does not appear to be shifting the diets of sharks.
However, there are still limitations imposed on how much bait and berley can be used. The rules stipulate that on the rare occasion a shark takes a bait, there must be a 15-minute review period in which baits and tourists are removed from the water.
“The cage-diving industry here in South Australia is one of the most strictly regulated throughout the world,” Meyer says.
Is everyone okay?
Meyer and other Flinders University researchers have also been investigating the effect of the cage-diving industry on other animals in the Neptune Islands ecosystem, which boasts more than 130 species of fish, marine birds and pinnipeds.
“It’s home to one of Australia’s largest colonies of long-nosed fur seals, it’s important nesting for a number of seabirds, and as one of South Australia’s marine parks and sanctuary zones, it offers important habitat and protection for a number of different marine species,” Meyer says.
The group’s research has found that bait and berley impacts other ‘non-target’ species, including the silver trevally.
“These fish aggregate around the cage and boats in huge schools,” Meyer says. “While the berley is not impacting the sharks, it is having a big impact on silver trevally, and has shifted yellowtail kingfish residency and diet.”
Better understanding these impacts on non-target species is the focus of Josh Dennis, a PhD candidate within the Southern Shark Ecology Group, who is studying how the bait and berley affects silver trevally abundance, movement and growth.
“The research goes beyond uncovering a single impact, or focusing on a single species – we need to know what an impact means for the next species, or the community as a whole,” Meyer says. “So we’re deploying underwater cameras along the seabed, extending around the cage-diving vessels to look at fish behaviour at a small scale, and across a number of offshore islands to explore fish communities at a large scale.”
Meanwhile, the cage-diving industry continues to report observations 12 days out of 14.
Tourism with impact
Both Rodney Fox Shark Expeditions and Calypso Star Charters operate out of Port Lincoln, with the majority of tourists going on a Calypso day tour, during which they typically view sharks for around 45 minutes in a cage just below the surface.
Fox’s operation, on the other hand, is more focused on submersible cages, getting people down to view sharks on the reef. Guests spend several days living aboard the boat, and every now and then have the chance to work alongside researchers such as Dennis, Meyer or Huveneers, who occasionally join Fox’s expeditions – as well as Calypso’s tours – to conduct research.
“But we also conduct research on their behalf, and we do a lot separately with own research foundation,” Fox adds. “[Tourists] love to be part of that, even if it’s just identifying and cataloguing the sharks, or allowing time to get biopsies or tags into the sharks.”
The tourism industry in SA is also an excellent platform for education, because there’s no doubt that white sharks have a PR problem.
Simply by joining a trip, the tourists themselves fund the research.
“Without that tourism platform it’s very expensive to get out to find such a rare elusive animal,” Fox says.
Meyer agrees; she says that this kind of reliable access to an aggregation of sharks is only made possible by collaboration with the cage-diving industry. She’s lucky enough to spend a couple months a year out at the islands, with a lot of time beneath the surface.
“Most of the research I do comes from the cage, because I need to take a biopsy of white sharks to understand what they’re eating,” she explains.
This involves being close to the shark – just a metre or two away – and using a modified speargun to take a small sample of a shark’s skin and the muscle underneath.
“From a single biopsy we can learn a lot about white sharks. We can do genetic analyses from the skin sample to see how big the population is and whether or not the number of white sharks in South Australia is increasing, decreasing or staying stable,” Meyer says. “We can also figure out how closely related our South Australian white sharks are to sharks from the rest of the world.”
Biopsies can also further inform researchers about the shark’s diet, as well as indicate the amount of heavy metals and other contaminants in their system.
Education, conservation and research – it just goes hand in hand.Andrew Fox
Meyer adds that the tourism industry in SA is also an excellent platform for education, because there’s no doubt that white sharks have a PR problem.
“A lot of people are either frightened of them or feel like they’re a risk to public safety, or even a risk to their fishing catches,” she says.
“Taking people out to see them in an environment that is safe, in a context where sharks are calmly and somewhat majestically swimming around without promoting that fearful ‘biting’ image that plagued the 1970s and 80s – what we get is a real shift in people’s perception of white sharks, and that does translate into conservation action.”
This is backed by research, according to a 2018 survey of cage-diving participants, which found that emotional engagement during a tour can enhance people’s knowledge of and attitude towards sharks.
Fox says that his business and foundation has been built on this exact platform: “Education, conservation and research – it just goes hand in hand.
“We make a lot of films and write a lot of journal articles and photographic features that go right through to literally hundreds of millions of people around the world, so it gives a lot of exposure to the state and the islands that we work at,” he says.
“There’s also a real growing fascination now, but you need the education to go along with it.”
And even after 40 years of diving with white sharks, Fox says that there is still so much to learn.
“I don’t get sick of them,” he says. “There are so many unknown questions about them still, and that keeps the magic going.”