This story was first published in Damaged Goods Zine
The ocean is everything. It is an immense and vast desert, surrounding and supporting human livelihood.
Perhaps no community in New Zealand relies on the ocean like Stewart Island does. The Islanders lives play out in unison with the ebb and flow of the Southern Ocean. The ocean is their lifeblood. Salt water flows through their veins. For Stewart Islanders, the ocean is everything.
On an island of just 450, the locals understand its importance in a small economy driven by its fisheries and eco-tourism. The roaring 40’s and a complex flow of currents provides the island with highly productive waters. Most Stewart Islands are thrown into the sea before they can walk and are rowing dinghies before they can write.
On the small, tranquil island the very ocean that surrounds it has become the setting of intense debate, a debate that seems to overshadow the Island’s low-key way of life. The controversy isn’t about the abundant Paua assemblages that inhabit the islands gelid waters, or the Titi Mutton bird, harvested annually by Rakiura Maori, but a far more emphatic species; the oceans most terrific, revered and fearsome predator: The great white Shark.
Since 2006, two businesses have cage dived with Great white sharks at Edwards Island, just 6km away from the islands main township, Oban. Stewart Islanders have reason to believe that shark cage diving has modified the behaviour of the local great white population. Many now fear the waters that has for generations, created a life for Stewart Islanders.
For 400 million years great white sharks have been one of the oceans top predators. While they may be the most feared animal on this planet, humans know surprisingly little about these iconic hunters. As a deep water, sparsely populated, migratory animal, great white sharks are extremely difficult to study.
They reside at the top of marine ecosystems as apex predators. They balance and control oceanic communities by preying upon other fish species. They are an evolutionary masterpiece, flawlessly designed and unchanged for hundreds of millions of years. While in the past, man has taken to the seas to hunt and kill great white sharks; we now understand their intrinsic value to the world’s oceans.
Occasionally great whites do prey upon humans. Scientists believe these attacks are the result of mistaken identity, rather than something more sinister. We are by no means an appropriate prey source for these sharks and in the vast majority of attacks, humans are only bitten once and no flesh is consumed. Because of this rare phenomenon, great white sharks have come to be popularly misunderstood as mythical, nightmarish denizens of the deep.
The Titi islands to the North of Stewart Island are a hotspot for great white sharks. The Islands is home to a seasonal population estimated to be anywhere between 50 and 120 individuals. Like other aggregation sites in Mexico, South Africa and Australia, the Northern Titi’s is also home to large seal and sea lion colonies.
Satellite tagging studies carried out since the mid 2000’s has shown that the majority of this population migrates annually. Between March and September, individuals migrate northwest to the tropical Australian and Pacific waters. The re-arrival of the sharks at the Titi’s coincides with the seal pup-birthing season in late December.
Great white sharks were protected in New Zealand in 2007. At that stage the population status of Great whites in NZ was unclear. Because of low reproductive and growth rates and concerns surrounding the impacts of fishing mortality, the sharks were protected under the 1953 Wildlife Protection Act. It is now illegal to hunt, kill or harm Great whites in New Zealand waters.
Shark cage diving has taken place at the Titi Islands since 2008. Peter Scott, once a commercial fisherman turned his shark cage diving hobby into a commercial venture. He began taking passengers to dive with sharks at Edwards Island, a small, narrow island in the Titis chain. Nowadays, two shark cage diving businesses operate out of Bluff- Peter Scott’s Shark DiveNZ and Mike Haines’s Shark Experience.
The companies have operated like most cage diving ventures; the boats arrive at Edwards Island, throw ground up fish, blood and oil into the water, wait for sharks to arrive, lower customers into the shark cage and keep the sharks interested by dragging a dead fish died to a rope outside of the cage. The operations became hugely popular with tourists and kiwis alike.
However, over time many Stewart Islanders began to voice their concerns about the cage diving operations. They began to report an increase in great white sightings and interest in human activity in the waters surrounding Stewart Island. The Islanders had reason to believe that the burley and throw baits offered to sharks by cage diving were beginning to behaviorally condition the Island’s local Great white population.
The concerns held by Stewart Island locals mirror concerns held at other cage diving jurisdictions around the world. The process reflects the psychological process of classic conditioning. The process is simple. It is a mechanism that occurs when two stimuli are consistently repeated, leading to basic learning.
Just like a dog learning to associate the sound of a bell with being fed, Stewart Islanders believe that the sharks now associate the presence of boats and people in the water with being fed. As a result, many believe that is only a matter of time before a shark in the Island’s waters will kill a diver or swimmer.
Stewart Island water users have reported an increase in great white sightings and interactions since the inception of cage diving at Edwards Island. There is an array of stories from the Island of sharks approaching and bumping fishing boats, sharks repeatedly swimming uncomfortably close to Paua divers and sharks following boats back to shore.
Of the most concerned are the region’s Paua divers. Each year 90 tones of Paua with an export value of $5 million is harvested in the waters around Stewart Island. 14 registered boats work the Stewart Island Paua fishery and parts of that fishery overlap with the area used by the cage diving operations. As years have progressed, tensions have heightened and Southland Paua divers are those that are most actively pushing to ban cage diving at Stewart Island.
While no one has been bitten since cage diving began in the island’s waters, it is a fear that continues to plague the island community. Paua divers now avoid diving in waters close to Edwards Island and local parents are wary of their kids swimming at Halfmoon Bay wharf. The locals just want cage diving gone.
Peter Scott and Mike Haines have fervently denied allegations that cage diving is impacting on the natural behavior of great whites in the area. Both operators have outlined that they are not ‘feeding’ the sharks. They believe that the burley put into the water to attract sharks is not large enough for sharks to eat and the number of throw baits has never been a substantial meal for the sharks.
Contrary to popular belief, great whites are highly opportunistic feeders. Their diet is highly variable and they will often divulge in an easy meal where possible. They are naturally inquisitive and are known to approach foreign objects on the sea surface.
Both Scott and Haines argue that the sharks have for decades scavenged off of local fishing boats and were already used to getting fed. After a days fishing, fishing boats toss guts and fish frames overboard after cleaning fish. Peter Tait, a Stewart Island eco-tourism guide and ex commercial fisherman offers an insightful anecdote on his website sailashore surrounding this idea:
“As a commercial fisherman I used to do a significant part of my cleaning in Braggs Bay, leaving a fair amount of cod frames on the bottom each evening. Next day they were always all gone. Add to this two sharks caught within Halfmoon Bay immediately after New Year around 20 years ago were both full of cod frames when opened up. Over a codding season I would estimate that I dumped in excess of 10 tonnes of fish offal into the tide between Ruapuke and Halfmoon Bay, as would most commercial fishermen, so the sharks could not be but aware at least of boats association with food.”
The controversy is one, which is steeped in scientific uncertainty. In the absence of evidence seeking to explain what affect, if any cage diving as had on shark behavior in the area, we are left with varying anecdotal accounts from parties both for and against cage diving.
Little was known about great white sharks in the area before cage diving commenced in Stewart Island waters. In a joint study, the National Institute of Water and Atmospheric Research (NIWA) and the Departement of Conservation (DOC) began tagging in 2005 around Stewart Island to understand the movements and migrations of the islands sharks. Because little is known about the sharks behavior before cage diving, it is now effectively impossible for scientists to accurately determine if cage diving has had any affect on the sharks behavior.
Until 2014, the two businesses operated unregulated. This meant that they could use limitless amounts of burley and throw baits. Amidst growing tensions between cage divers and those against them, DOC stepped in to attempt to manage the controversy. In December 2014, DOC introduced a permitting system and in December 2015 DOC released an updated code of practice for shark cage operators. Together, they limited what could be used to attract sharks whilst restricting cage diving activities to an area 300m within Edwards Island.
Cage dive operators are permitted to use unlimited amounts of burley, which must be finely minced. Throw baits are not permitted to be consumed by sharks and if they are, no further throw baits are allowed to be used on that day.
Under further pressure, in late 2015, DOC set out to review the science surrounding shark cage diving. DOC commissioned Barry Bruce, a renowned Australian Great white scientist to research and collate information scientific information on the topic. The review provides a thorough exploration of global shark cage diving activities, scientific research and management practices.
While the science on Great white response to cage diving is limited, Bruce concludes that, “overall, it would seem unlikely that white sharks exposed to cage diving activities are any more or less likely to present a risk to divers, swimmers or surfers in areas away from cage diving sites than any other shark”.
Politically, scientifically and ethically, the issue of cage diving at Stewart Island is a murky one. Anecdotal knowledge seems to both support and work against theories of behavioral conditioning associated with cage diving. It seems that the shark’s capacity to learn is at the crux of the argument. In July this year Dr. Daniel Burcher, a marine scientist at Lismore University, NSW, Australia, told me a story of a Tiger shark that had learnt to associate a particular boat in Australia with being fed:
“There’s a good story from Heron Island where the garbage boat, would take the garbage out from a resort and a big Tiger shark used to wait outside the channel. And as soon as this boat went along it would follow it out and gobble up all the garbage. Well when the marine park came in and said “no more dumping of garbage in the channel”’, they had to put it on the big barge and send it back to the mainland for landfill. So they took the motors of the garbage barge and put them on a dive boat. Sure enough, the shark followed the dive boat… I think there’s definitely some capacity to learn.”
The anecdote offered by Dr. Burcher suggests that this singular Tiger shark had been conditioned. It suggests that Great whites could too, be capable of learning to associate boats with being fed. But does cage diving offer Great whites at Edwards Island a substantial amount of food to learn? Would a learned association last for a significant amount of time? Would it pose a danger to other human water-users? There are more questions than answers amidst the cage diving controversy at Stewart Island.
As long as cage diving continues at Edwards Island, the controversy will remain. Conclusive information on the effect of cage diving on Great white behavior doesn’t appear to be coming any time soon. For the most part, wider New Zealand has been fairly uninterested in the issue. Theoretically, if the controversy were taking place in Auckland harbor, it would capture the interest of our nation. But for now, no one has been attacked and for the rest of the country it’s out of sight and out of mind.
The reality of the situation is that wherever humans and large numbers of sharks share the same environment, an attack is likely to be inevitable. It could happen tomorrow, it could happen it 10 months or it could happen in 10 years. At that point it will be impossible to untangle the cause of the attack and the controversy will capture the nations interest. Stewart Islanders will demand retribution, cage dive operators will refuse that their businesses had any affect on Great white behavior, and our government will have a legal, ethical and political mess to deal with. But as we move into summer, cage diving will once again commence at Edwards Island.