OPINION: Silver linings in a tourism grey area

Dr Lauren Meyer explains the issues in ensuring sustainable shark tourism.

Cage-diving with white sharks is one of our most popular marine wildlife tourism activities, but what are the impacts on these amazing creatures, and can South Australia’s cage diving industry become the gold standard in sustainable shark tourism?

Coming face-to-face with our top predators – with the protection of a cage – remains at the top of many bucket lists. Each year, thousands of thrill seekers and conservationists are lured to the Neptune Islands off South Australia’s Eyre Peninsula in the hope of seeing iconic white sharks in action.

While cage-diving was pioneered in South Australia in the early 1980s, forty years on the conversation around white sharks and tourism has changed dramatically from conjuring and conquering fear, to promoting sustainable tourism. But what sustainable tourism looks like and what is an acceptable practice is often debated, making wildlife tourism a complex industry to manage.


The Neptune Islands are home to three locally owned white shark cage-diving operators, who prior to COVID-19 collectively hosted up to 10,000 passengers each year, contributing $15 million to the local economy annually.

While this is big money for a small non-extractive industry, the operation is not built on profit alone. It also offers several invaluable benefits – that make all the difference in tourism sustainability.

By enabling the public to safely interact with our top predators, these industry operators encourage education on sharks and enhance the perception of the traditionally misrepresented creatures – fostering stewardship of natural areas and wildlife more broadly.

These benefits are more than nice sentiments and a pat on the back on the boat trip home. Continued public support underpins long-term marine conservation success.

Cage-diving also provides scientists with unparalleled opportunities to undertake cutting edge research, contributing to our understanding of sharks and the local ecosystem.

Despite these benefits, cage-diving at the Neptune Islands can, if unmanaged, impact the species it targets and the ecosystem it relies on.


Scientists, managers, industry operators, and the public have voiced concerns about the use of bait and berley to attract sharks for cage-diving purposes. Berley is unsellable tuna from the local aquaculture industry, which eliminates waste and recycles a local marine product that is naturally on the menu for white sharks in South Australia.

Although strict regulations prevent intentionally feeding white sharks, some occasionally catch and consume the bait – they are highly evolved, agile, intelligent ambush predators after all.

Yet our research has found that this occasional consumption is not enough to alter their diet, and the time they spend chasing baits does not detract from their natural feeding opportunities.

However, the cage-diving industry has been attributed to an increase in residency where the sharks spend more days at Neptune Islands and expend energy chasing baits. But these changes have been mitigated through policies to reduce the number of days operators can be at the Islands and by regulating the amount of bait and berley used.

These findings and regulations are an important step in ensuring South Australia’s cage-diving remains minimally invasive.


The Neptune Islands are home to over 130 different marine mammal, fish, and bird species that each play an important role maintaining a functional ecosystem within this marine protected area.

Our research found that these species face similar benefits, concerns, and challenges arising from the cage-diving industry as the more iconic white sharks. However, one seems even more interested in the bait and berley than the white sharks, which is having a surprising ecological impact.

Roughly 3,000 Silver Trevally live in the waters of the Neptune Islands and are the bane of photographers, tourists, and even scientists trying to spot sharks through the mass of these fish eagerly consuming the bait and berley.

But these annoying fish do a very important job. They moderate the impact of cage-diving on the broader ecosystem by quickly consuming berley before it reaches the sea floor and is eaten by other species.

Silver Trevally are nature’s way of balancing the ecosystem and are an ecological silver lining in a cage-diving sustainability grey area.


As the pandemic eventually abates and we look to book holidays to interact with wildlife, consider what you can do to promote sustainable and acceptable wildlife tourism.

Find industries and operators that are locally owned, have an education component to their tours, and explicitly support research and conservation.

Keep an eye on marketing and messaging. If negative perceptions of wildlife are promoted, unethical interactions are encouraged (sharks and other wild animals should never be touched), or they put the safety of tourists or wildlife at risk – find a different operator.

And be aware of the messages you send with the photos you post online.

Last but not least – enjoy the wonderful wildlife.


2021 Encounter magazine – Read more

Posted in
2021 Encounter magazine College of Science and Engineering Environment

Leave a Reply