Shark attack prevention : keep off their dinner table (Australia)

ABC News

November 3^rd, 2014 (Bill Brown). Shark behaviour experts say that understanding the behaviour of sharks is the best way to avoid being eaten by one.

Increased sightings of White Pointer sharks along the NSW far south coast has created speculation that the shark population and the threat of attacks is increasing.

“But it’s just a temporary situation,” says licensed shark fisherman Alan Broadhurst.

Mr Broadhurst told ABC South East NSW that sharks follow their food source and at this time of year the whale migration is attracting White Pointers.

“When the whales are coming down with the calves it’s an ideal opportunity to get themselves a good meal,” he said.

Shark expert Guy Richards agrees: “Sharks follow their food source.”

At this time of year there will be Bronze Whaler sharks following those schools of fish, and as the water warms up the Makos and Hammerheads will be on the hunt as well.

They are hunting for fish.

“If there are large schools of mullet and salmon close to shore, well of course you’ll have predators.”

So the simple way to avoid be included in the meal is to avoid swimming when the sharks are hunting and where there are schools of their target fish.

Sharks are feeding more actively at sunrise and dusk and so surf lifesavers advise that people avoid swimming at sunrise and dusk.

Or as Guy Richards says: “If you go and hop on someone’s dinner table they might stick a fork in you.”

As most surfers know, if you see schools of salmon or mullet racing by then it’s very likely something is chasing them, so it’s a good time to be out of the water.

Mr Broadhurst believes there are less sharks along the far south coast now than there were in the 1970s.

He says they breed so slowly that the number of sharks coming out of the water is far greater than the rate at which they can re-populate.

The following description of the sharks mentioned above is courtesy of the NSW Department of Primary Industries.

Great white shark

Alternative names: white pointer, white shark, white death.

Great white sharks, Carcharodon carcharias, are found near shore along most of the world’s temperate coastlines but are relatively scarce compared to most other widely distributed shark species.

In Australia, great white sharks have been recorded from central Queensland, around the southern coast to North West Cape, Western Australia, but are more common in the south.

Only the underbelly is white: the top surface is grey to blue/grey or bronzy.

The biggest recorded specimen was 7 metres long and 3200 kg. The teeth are large, sawedged and triangular. The diet of young great whites (under about 3.5 metres) is mainly a variety of fish, rays and other sharks. Larger adults eat larger prey including marine mammals such as sea lions and seals, small toothed whales and otters.

They also eat dead animals floating in the water. More attacks on humans, including many fatalities, have been attributed to the great white shark than to any other marine animal. Great whites are a protected species in many Australian states including NSW, and also in several other countries.

Bronze whaler

Bronze whalers, Carcharhinus brachyurus, inhabit many temperate seas and oceans around the world. They are often seen close inshore feeding on schooling fish such as salmon but are also found near deep water where they prey on squid and bottom-dwelling fish.

They are large, up to 3.5 metres and 300 kg, are potentially aggressive sharks that have attacked people and can be dangerous to spearfishers with fresh catches as well as towards surfers, as their natural prey is often found in the surf zone. Colour is grey to bronze on the back, and white below. The pelvic and pectoral fins can have dusky to black tips.

Mako

Both the shortfin mako, Isurus oxyrinchus, and its longfin cousin, Isurus paucus, are commonly called mako shark.

On average the shortfin species, found in offshore temperate and tropical waters to depths of 150 metres, reaches around 3.2 metres and 400 kg. It occurs along the entire NSW coast, and is widespread in most of Australia’s coastal shelf and ocean waters. Colour is bluish black with a white underside and a hydrodynamic shape which provides spectacular speed and agility.

Prey is mainly bony fish as well as other sharks, sea turtles, herons, dolphins and possibly scavenged long-lined and netted fish. Makos are renowned for their ability to leap out of the water and cases of angry makos jumping into boats after being hooked have been recorded.

Hammerhead

There are nine species of hammerhead sharks, three of which are known to occur in NSW waters: the smooth, scalloped and great hammerheads.

In Australia, smooth hammerheads occur south from Coffs Harbour to about Jurien Bay, Western Australia, and are the most common of the hammerheads in NSW. Females are thought to give birth in nearshore waters of the NSW coast between January and March, when they are often observed in large schools swimming just outside the surf zone of NSW beaches.

The scalloped hammerhead is recorded throughout the north from Sydney NSW to Geographe Bay in Western Australia. The great hammerhead prefers tropical and warm temperate seas, and occurs north from Sydney NSW to the Abrolhos Islands off Western Australia.

Hammerheads range from under 1 metre, up to the great hammerhead (Sphyrna mokarran) averaging 3.5 metres, but with a largest reported size of 6 metres and 450 kg.

Great hammerheads have a wide, thick head with eyes at the margins of the hammer which is almost rectangular in shape. It is greyish brown above and off-white below, and is found in temperate to tropical waters worldwide along coastlines, the continental shelf and adjacent drop-offs to about 80 metres.

A migratory predator with a good sense of smell, it eats fish, squid, octopus, crustaceans and, in particular, stingrays.

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