tales

Blacktip reef know each other as individuals and often travel with favoured companions.

Text by Ila France Porcher The first time I met a shark, I was struck by silence. Having observed the of the Canadian mountains all my life, my knowledge of sharks was limited to the information gained from watching the movie Jaws many years before. All that remained from that brief edu- cation was that they bit—and badly. Very badly. Essentially, if you met one, you died.

But now I was living in Tahiti. I had been told that there were no sharks in the lagoon, and they were far from my mind as I roamed one morning upon the bar- rier reef. The sunshine ran in golden lines across the coral and flashed upon the fish. It was mesmerising. When I raised my eyes, a grey shark of about my size was moving languidly towards me and all my lights went on. Everything about her was just right—her Sharks: Still Misunderstood curves, her fins, her face—nothing had PIXABAY prepared me for the sight of that splendid creature gliding forth through the rushing keep the coral between us, and when at me, and I began to seek them out having learnt in university that they, as well sequent sightings. I wanted to find out landscape, as graceful as a snake. I peeked out to see her again, she was each day on my underwater forays. They as other animals of the “low” and “cold” what they were like, not only as animals, Expecting her to fly into attack mode gone as if she never had been there. were the first wild animals I had met that variety, were practically brainless. but as individuals, and visited them sev- at the sight of me, I held my breath and came, instead of fleeing. eral times a week, whenever I could. The drifted behind a coral. But she paid me Not brainless It was soon clear that their complex and Individuals and social animals ability to recognize them as individuals not the slightest attention as she passed After a few more sightings, I found that flexible behaviour was very different from So, I launched an intensive study of the revealed a whole new dimension of their just a metre away. Her smug little face if I remained very quiet in the water, the the other wild animals I had known. I was local blackfins, identifying each one by lives, and I had the feeling of a window actually looked bored. I moved to blackfin reef sharks would come to look especially intrigued by their intelligence, its markings, and keeping track of sub- opening onto another world, one so sep-

38 X-RAY MAG : 91 : 2019 EDITORIAL FEATURES TRAVEL NEWS WRECKS EQUIPMENT BOOKS SCIENCE & ECOLOGY TECH EDUCATION PROFILES PHOTO & VIDEO PORTFOLIO THIS PAGE: Blacktip reef sharks are social and emotional animals that seek the companion- ship of others and display complex behaviours, shark tales including anger, affection and attachment. Misunderstood

face and slid against the boat, the pad- nary animals with high intelligence and a dle, and oscillated from one to the other. repertoire of behaviours that is still misun- They revealed this emotional attach- derstood and mostly unknown. ment on another occasion too. Instead of Divers, being the only people to meet staying for an hour and a half as I usually them in their own environment, need did, I just came to give them some treats, to take the lead in insisting that they be and then had to rush home. As soon as I protected from further depletion through approached the kayak, and they under- , and especially from the shark stood that I was about to get into it, they fin market that is driving them towards all soared over and began to circle me. extinction.  Then, as I paddled home, they followed. Thirty-six sharks accompanied me out of Ila France Porcher, author of The Shark the lagoon and some distance down the Sessions and The True Nature of Sharks, is deep bay towards my house before they an ethologist who focused on the study began to turn back, one after another, of reef sharks after she moved to Tahiti in circling back towards the lagoon, return- 1995. Her observations, which are the first ing, then finally returning to the shallow of their kind, have yielded valuable details turquoise waters where they lived. about their lives, including their repro- ductive cycle, social biology, population Deserving of protection structure, daily behaviour patterns, roam- The difference between true shark ing tendencies and cognitive abilities. behaviour, and their awful reputation, is For more information, please visit:

LAURA WOLF / FLICKR / CC BY 2.0 very exaggerated, but sharks are ordi- ilafranceporcher.wixsite.com/author

arate from human life that it might just as directions, when I arrived. Yet, I never against it. One slid against the paddle, well have been on another planet. saw them fighting, and speculated that and all around me they placidly glided, Soon the resident sharks, often accom- this was because they were not territo- dorsal fins above the surface, pushing the panied by visitors, were waiting for me to rial, so greeted visitors to their region with curves of their bodies against my boat, arrive; they could recognize the sound friendliness instead of hostility. moving beneath and pressing against it, of my kayak from far away. They were Then a company from Singapore got again and again. I reached down and social animals and those in the lagoon set up throughout the far-flung archipela- stroked them as they passed, instinctively were the females, each spending much goes of that island nation and began responding to what could only be inter- of her time in a region about 500m slaughtering the sharks for their fins. preted as an affectionate gesture. across—her home range. They knew My sharks fled at first, and when some The sharks did this each time they met each other as individuals and often trav- returned, their society was in disruption. It me after that. One was always first to elled with a favoured companion when was two years before the divers, with the swim slowly beneath my hand as I sat they left home. Some roamed away help of international pressure, were able in the low kayak and I would stroke her. often, for weeks or months at a time, to convince the government to protect She would spend some time drifting back while others were stay-at-home creatures them; French Polynesia is now the largest and forth while being caressed, then and were only absent twice a year, once in the world. undulate against the kayak and disap- to mate, and once to have pups. There pear below. were a few males who regularly passed Affection and attachment On one evening of perfect calm, through that part of the lagoon but most- During the period in which they were through the flawless clarity of the water, ly they remained in the ocean on the being finned, because of personal dif- I saw the group of sharks shoot straight other side of the barrier reef. ficulties, I was unable to get out to see upwards from two metres beneath, them, and when I finally made it back, undulate against the boat, and go Display of emotion two months had passed. As I crossed into straight down again, so that their tails The blackfins were emotional animals. the sharks’ lagoon, I paused to drink some flashed above the surface around me During one episode, the entire group got water and suddenly, there was a blackfin momentarily like the wings of birds, drop- mad at me, and for several weeks, they drifting past the boat, with more coming lets flying. There were several of them on would slam my kayak hard, from multiple beyond, and they began to undulate each side. Then they returned to the sur-

GEOFF SHUETRIM / FLICKR / CC BY 2.0

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Queensland ordered to suspend controversial shark control program

The shark con- trol program has been suspend- ed after a tribunal ruled sharks found alive on drum lines must be released. G.Mannaerts The decision has come after Humane Society International (HSI) earlier this year launched a challenge to the shark control program run by the Department of Agriculture and .

It is ineffective G.MANNAERTS4.0 BY-SA / CC In its decision, the Administrative Appeals Tribunal said the scientific evidence about “the lethal component” of the shark con- trol program “overwhelmingly” showed it Drum lines have been swimming beaches with the does not reduce the risk of unprovoked deployed with the intent of intention of reducing the num- shark attacks. Humane Society International preventing shark attacks in ber of sharks in the vicinity, campaigner Lawrence Chlebeck said non- Queensland, Australia, since and therefore, the probability lethal technology was the way forward for 1962. In January­ 2014, drum of shark attacks. lines were introduced in shark control in the Great Barrier Reef. “This Since the objective of the to catch drum line is to prevent sharks is a massive victory for sharks and marine potentially hazardous sharks. from approaching popular wildlife,” he said in a statement. The topic of shark beaches (and not to attract became a nationwide con- them) only about 500 grams of The Great Barrier Reef Marine Park will now troversy and sparked public bait are added to each hook. only be permitted to authorise the eutha- demonstrations and vocal Thus, sharks are only attracted opposition, particularly from nasia of sharks caught on drum lines on ani- to the baits from the immedi- environmentalists, animal wel- mal welfare grounds, “specifically when a ate vicinity. shark is unlikely to survive release due to its fare advocates and ocean condition or an injury, or which cannot be activists. Drum lines have been cited as safely removed alive due to weather con- A drum line is an unmanned not being an effective strategy ditions or hooking location”. Furthermore, aquatic trap used to lure and to keep people safe, while contractors must attend to caught sharks capture large sharks using simultaneously killing thousands within 24 hours, and all tiger, bull and white baited hooks. They are typi- of sharks and other wildlife in the marine ecosystem. sharks to be tagged before release.  cally deployed near popular

40 X-RAY MAG : 91 : 2019 EDITORIAL FEATURES TRAVEL NEWS WRECKS EQUIPMENT BOOKS SCIENCE & ECOLOGY TECH EDUCATION PROFILES PHOTO & VIDEO PORTFOLIO shark tales Shark’s electrical sense is finely tuned to detect prey It has been known for many years that rays and sharks are able to detect min- ute changes in electric fields, much like the way our ears react to sounds, as they swim and use this sense to detect prey.

A network of organs, called ampullae of Lorenzini, constantly survey the elec- tric fields sharks swim through. Electricity (File photo) Can enters the organs through pores that electrical deter- surround the animals’ mouths and form rents make sharks intricate patterns on the bottom of back off when their snouts. Once inside, it is carried via they are get- a special gel through a grapevine of ting too close for canals, ending in bunches of spherical comfort? cells that can sense the fields, called electroreceptors.

But as the electrical fields manatinge from nearby prey are very weak, how

PETER SYMES do they pick up these tiny changes against the backdrop?

Much like humans can pick out certain How effective are commercial electric anklet specific sounds or voices in an other- wise noisy environment, a shark’s elec- shark deterrents really? trosensing organ is finely tuned to react to the minute changes in electrical Shark researchers from The Whether or not these kinds of devices ac- Barely any effect fields emanating from nearby prey in a University of Western Australia tually do anything is the subject of a new An active ESDS was no more capable of sudden, all-or-none manner, as if to say, Great whites have high study published in PLOS One, and unfor- keeping sharks at a “safe” distance than “attack now.”  tested the effectiveness of tunately, it seems that there are some an inactive ESDS. Sharks would routinely tolerance to heavy metals the Electronic Shark Defence pretty huge differences, depending on approach within 20 to 30cm of the de- Great white sharks off South Africa have which brand you choose. To determine vice, whether it was active or not. There “Although the effectiveness of the ESD- System (ESDSTM) and found it been found to contain quantities of just how effective the device is, the re- was no significant reduction in the pro- STM may vary between species, due to unlikely that the device would heavy metals that would be danger- searchers tested it against a large popu- portion of sharks interacting with the bait species-specific differences in electrore- ously toxic to other forms of marine life, significantly reduce the risk of lation of white sharks (C. carcharias) in a in the presence of the active device. ceptive ability, the fact that white sharks according to a newly published study in a negative interaction with a shark hotspot in South Africa. The device are implicated in the majority of fatal which researchers screened the blood tested was a commercially available an- Only very close up (< 15.5cm), did the incidents globally suggests that a device white shark. samples for concentrations of 12 trace klet called the Electronic Shark Defence active ESDS show a significant reduction that cannot effectively deter this species elements and 14 heavy metals. Personal shark deterrents offer the poten- System, or ESDS, which produces an elec- in the number of sharks biting the bait, should not be considered an effective The results showed high concentra- tial of a nonlethal solution to protect indi- trical field that the manufacturer claims but this was countered by an increase shark deterrent,” said Dr Ryan Kempster, tions of the metals, including mercury viduals from negative interactions with drives sharks away. in other, less aggressive, interactions. lead researcher of the study.  and arsenic, which did not correlate sharks, but the claims of effectiveness By comparison, an active Shark Shield SOURCE: PLOS ONE to a shark’s sex, body size or condition. of most deterrents are based on theory The team recorded 395 encounters with deterrent (which was previously tested by The results suggest that the apex preda- rather than robust testing of the devices 44 individual white sharks. The researchers the team using the same methodology), tors have a built-in ability to tolerate the themselves. found the ESDS had limited meaningful effectively deterred white sharks by an negative effects of the heavy metals.  effect on the behaviour of white sharks. average of 1.3m from the device.

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