Shark attacks don't warrant increased cull

Shark attacks don't warrant increased cull - ABC News

Australia is not alone in having large sharks near populated beaches or for having a reputation for shark attacks.

South Africa is the world's hotspot for great white sharks. It is where documentary makers come to film the dramatic scenes of white sharks breaching in the chase for Cape fur seals and it is the centre of the great white shark cage diving tourism industry where, on a daily basis, fleets of boats head out of the tourism centres packed with people wanting to view a great white shark from the safety of a cage.

In terms of documented attacks, there were six in the period from 1951 to 1970, 25 incidents between 1981 and 1990, 23 incidents reported from 1991 to 2000, and 11 reported great white attacks in the first half of this decade.

In some years, there were anomalously high numbers of attacks, such as Black December in 1957 when five people were bitten by sharks south of Durban, or 1998 when a total of 18 attacks were recorded in South Africa.

The longer term trend of rising incidents since the 50s and 60s mirrors an increase in beach use but cannot explain the year-to-year variations. To date, science cannot conclusively say why there are higher numbers of shark incidents in some years compared to others. It is likely that an array of oceanographic, ecological or behavioural factors are to blame for bringing more or fewer sharks in contact with people in any particular year, but the specific causes remain unknown.

Already it looks like 2009 will go down in the record books as having an anomalously high number of shark attacks in Australia and in the Sydney region in particular. Just as with South Africa, more people in the water increases the chance of an interaction. A cleaner Sydney harbour also increases the chance of finding sharks as well as fish, but it is not clear what other biological, environmental or behavioural factors, if any, are adding to the high recent number of attacks.

There is no doubt that any shark attack is a terribly unfortunate and traumatic incident. Our sympathies are with the victims and their families. On a global scale, elephants, bees, crocodiles and lightning strikes kill more people each year than shark attacks, and beachgoers are at a far greater risk of death by drowning from rips or surf, yet the thought of being attacked by a shark remains a terrifying prospect.

Actions that can help ensure bather safety include increased investment in education and awareness program so that people understand basic rules. Some of these include avoid swimming alone, avoid being in the water when there are low light levels or reduced visibility, don't swim in waters with known effluents or sewage and stay away from fish or gull feeding areas.

Increased investment is needed in research and development, and testing of options such as observer programs, use of electromagnetic field technology and new shark repellent advances in concert with research into sharks, so that we understand more about the behaviour, ecology and environmental cues that affect these species. Together these will allow bather safety programs to be designed to be as targeted and effective as possible without also causing the deaths of marine creatures such as dolphins and turtles that also call the ocean home.

Of the more than 300 species of shark found in Australian waters, there are only a couple of species, most notably the great white shark and bull shark, that are recorded as attacking humans. The vast majority of sharks are shy elusive creatures that appear in a range of often bizarre shapes and sizes, patrolling reefs and open oceans where they fulfil a critically important role at the top of the food chain.

In terms of their reproduction, sharks are long-lived, slow growing and produce relatively few young, which gives them a population dynamic that is more similar to whales and dolphins than to fish. This makes shark populations vulnerable to over-fishing.

The history of shark fisheries the world over is one of 'boom and bust' where excessive fishing pressure causes populations to crash.

The result is that shark species are increasingly finding their way onto the lists of at-risk or endangered species, almost as quickly as new species are being described.

The high price being paid for shark fin in the Asian marketplace appears to be driving a gold rush type mentality around shark fisheries in Queensland and New South Wales. Opportunistic fishers push fisheries managers to increase shark catches and create new shark fishing licences, despite there being no scientific basis that such levels of take are within safe limits for the large numbers of species involved.

With sharks very much in the spotlight, cool heads need to prevail.

The calls for an increase to the shark fishing quota in NSW are driven by this opportunism. Some fishers are using the current media feeding frenzy around sharks to call for an increase in shark hunting levels and are making claims that have no scientific basis. They should be ignored.

Many of the sharks they already catch are docile creatures that are not involved in attacks on bathers. Some of the populations of shark species that these fishers pull out of the water for their fins and flesh are in steep decline.

This is not to deny that we need to find ways to ease the interaction between sharks and humans along our beaches. There needs to be an investment in education, awareness and research and development, so that bather safety programs can be as effective as possible.

But equally, we need to protect the dwindling populations of sharks that have lived in our planet's seas for millions of years. There is no justification for increasing a fishing quota that could see these ancient creatures disappear from our oceans.

Dr Gilly Llewellyn is World Wildlife Fund-Australia's oceans program leader

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Freak Bull Shark?

Bizarre Bull Shark Record:
Wednesday 28 January 2009

Cape Town: In a bizarre twist, the day before a lifeguard lost his life to a Zambezi shark on the Wild Coast, the world's largest was caught 5.5 kms up a river in the Western Cape, reports Wavescape

Yes, the Western Cape! International and local records tumbled as a team of shark conservationists hooked the largest Zambezi shark known to science - a massive pregnant female four metres in length and weighing almost half a ton. But wait for it. This awesome creature was found 5.5 kms up the Breede River, a large river that comes out near the southernmost tip of Africa, Cape Agulhas. It is the furthest south a bull shark has been found in Africa.

Visitors, holidaymakers and home owners who have frolicked in the river over the years, expressed stunned surprise at the news.

But for conservationist Meaghen McCord, managing director of the SA Shark Conservancy, this is a ground-breaking realisation of carefully planned scientific research. For a while now, fishermen have spoken about huge Zambezi sharks interfering with their lines in the river. More than a few have laughed at this claim. Well, the second expedition by McCord and her team has proved it to be true.

Joining them were representatives from Marine and Coastal Management, officers from the Lower Breede River Conservancy, a marine biologist from Marine Dynamics, and professional anglers from Big Fish Safari, said McCord. Running from 19 to 25 January, the first three days of their reserach yielded nothing, despite a gruelling regimen fishing with live bait for 16 hours a day.

However, on the fourth day, Friday January 23, a female they affectionately named Nyami Nyami after the Zambezi river God, was hooked by professional angler Hennie Papenfuss. According to McCord, 'Hennie gently handled the shark, letting her tow him a further 2.5km (say what? - ed), tiring her out before we brought her close to shore and landed her on a mud bank'.

'One can only imagine how excited we were to finally see such a magnificent animal in the river, but our excitement did not prevent us from gathering all the necessary scientific data and attaching two acoustic tags to track her movements during the following days.'

Over the next few days, the team discovered three amazing facts:

1 Nyami Nyami is the largest Zambezi shark known to science (four metres long and weighing between 400 and 500 kilos). The previous known maximum length is about 3.5m

2 The furthest south Zambezis have been found is Cape St Francis in the Eastern Cape. Nyami Nyami is the only animal ever observed in the Western Cape, and she is the biggest ever!

3 Nyami Nyami looked heavily pregnant, suggesting the Breede River could be an important nursery

 

Nyami Nyami was subsequently tracked for 43 consecutive hours. 'As far as we know, this is the longest time this species has been tracked. She moved up and down the estuary, following fishing boats and looking for an easy source of food, swimming as far as 15km upriver,' McCord said.

Bru, put that in your pipe and smoke it. How weird is that? I mean, this is a river that flows through the Cape winelands, passing Tulbagh and Swellendam on its way to the waters east of Cape Agulhas. Classic!

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