ISSUE 24 ARCHIVE - SHARKIPEDIA

Richard Peirce

Jaws flip over

In the 1975 film Jaws, the presence of a Great White shark threatened the prosperity of a fictional seaside town called Amity. In real life in 2016 and 2017 the absence of Great White sharks threatened jobs and businesses in the South African town of Gansbaai.

Cage diving with Great Whites occurs in South Africa around Dyer Island (Walker Bay), in False Bay, and in Mossel Bay. Of the three the Dyer Island location, offshore from the town of Gansbaai, is by far the most popular with local and overseas tourists. It is the self-styled 'Great White Shark Capital of the World'. Eight operators all doing up to three trips a day service thousands of tourists a year, and directly and indirectly provide hundreds of local jobs. As well as the cage operators, restaurants, guest houses, hotels, souvenir shops, and others all derive benefit from Great White shark eco-tourism. Cage diving around Dyer Island started in the late 1990's, roughly 20 years ago, and has built into a multi-million-dollar industry.

The sharks were a money tree, and the good times were never going to end – until the sharks disappeared! Then the horrible reality sunk home that the leaves had all fallen off the money tree and been blown away. In early 2016 the Great Whites disappeared for three weeks, and at that time various theories were put forward to explain their absence. In 2013 a pod of Killer Whales (Orcas) were observed in the area for the first time. More Orca sightings followed in 2015 and 2016. First a pod of six were seen, and then a pair of males were observed with distinctive collapsed fins. The fin of one animal fell to the right and the other to the left – they were nicknamed Port and Starboard.

On February 7th 2017 Port and Starboard were again spotted near Dyer Island, and on the 8th a dead 2.7 metre shark washed up on a nearby beach. The body was intact but there were scratch marks around its head. At the same time operators started noticing an absence of Great White Sharks, and as in the previous year they did not return for three weeks.

For shark enthusiasts and the operators life went back to normal, until on May 4th a 5 metre female Great White was washed up, and the scientists who conducted the autopsy revealed that her liver had been removed. There was a large neat hole in her belly between her pectoral fins, and when another shark was discovered the next day, this time a male, the wound was found to be in the same place, and its liver, heart and testes were missing. Once again shark sightings stopped, and there was to be no let up for the beleaguered town and its cage diving operators, because on Sunday 7th May another shark was discovered less than 100 kilometres along the coast at Struisbaai, and once again its liver had been removed.

The scientists doing the autopsies were convinced that the cause of death, and the removal of the livers, was due to predation by Orcas, and Port and Starboard were the prime suspects. The sharks appeared to have fled in terror when faced with a superior predator, and people in the Gansbaai area continued worrying about their livelihoods and financial futures, as day after day Dyer Island's waters were empty of sharks.

Then the bodies stopped washing up, and each day hope increased that the sharks would return. These expectations were dashed on June 24th when dead shark number four was discovered on a beach with the by now familiar wound in its belly, and its liver gone. On the same day Port and Starboard were seen and filmed patrolling the area, and fears for the future tightened their grip on the 'Great White shark Capital of the World'.

With the sharks gone Port and Starboard then also left the area, and as the weeks passed the sharks returned and life in the Gansbaai cage diving community slowly went back to normal. However locally based shark biologist, Alison Towner's optimism was tinged with more than a little pragmatism when she told me, "They are around, they have become specialist feeders, and they will probably be back." Alison's words proved prophetic and indeed Port and Starboard did return, and the Gansbaai operators adjusted to the new reality of Great White sightings being a lot less reliable than they had been.

One operator went out of business, and there were rumours that others would follow. Then help arrived when Bronze Whaler sharks started appearing around the cage diving boats. 'Bronzies' grow to nearly 3 metres in length and are impressive animals. They responded well to the chum deployed to attract Great Whites and were a lot of fun for the cage divers. They gave the whole local shark eco-tourism industry a much needed shot in the arm.

Last year wore on towards its close, Great Whites were seen sporadically, and the Bronze whalers helped fill the gap. Although the absence of Great Whites was worrying and depressing for eco-tourism, the Orca predation was exciting in other ways. We were witnessing a battle between two apex predator species which could change the marine ecology in the Dyer Island area. Orcas have only rarely been sighted in Western Cape waters, and although history and science may eventually discover an anthropogenic influence has contributed to the presence of the Orcas, for now we can only be sure that we are watching a natural clash of two ocean giants.

A new adventure

I consider the story of the Great White shark Nicole to be one of the greatest shark stories of all time, and I always wanted to tell her story. My latest book Nicole does just that. The book tells how in late 2003 a 3.8 metre female Great White shark was satellite tagged near Dyer Island, then starting with the pop off of her tag in February 2004 off Western Australia, and finishing in late 2004 with her reappearance near Dyer Island she re-wrote Great White shark history. The book is selling very well and I am delighted, not just because all authors want their books to sell, but also because I am thrilled that so many people are interested in her story and that of the scientists who shared her adventure.

My publisher was as keen as I was to find a suitable follow up, and I realised it was staring me in the face! My next shark book will be called 'Orca', and will chronicle the epic battle between Great Whites and Orcas in the waters around Dyer Island. Look out for Orca in early 2019.

No limits

Closer to home at last attention is focusing more on Makos and Blues in the north Atlantic. The Shark Trust's 'No Limits' campaign was launched nearly four years ago, and highlights the need for catch limits on several north Atlantic species including Makos and Blues. Makos particularly need our attention – and fast. Please go to the Trust's website and check out 'No Limits', we need your help and support. So plugs for 'Nicole' and 'No Limits', and now I will end with a final plug for the Shark Trust/Reef & Rainforest predator holiday trip to South Africa which I will lead in mid-2019. Big sharks and big cats – should be fun, once again check it out on the Shark Trust website.

Keep well guys, have fun, and be conservation and environmentally aware.