Friday 31 July 2020

Western Australian surfer recovering after Shark attack.

A surfer is recovering in hospital after a Shark attack off the coast of Bunker Bay, near Dunsborough, in southern Western Australia on Friday 31 July 2020. The incident happened at about 2.15 pm local time, when he was attacked from below by the animal, believed to have been a Great White, Carcharodon carcharias, which bit him on the legs before disengaging and swimming off, a pattern typical of Great White attacks. The victim was able to reach shore with the aid of other surfers, where he received first aid at a nearby home before being airlifted to hospital for further treatment.

A Shark near the beach in Bunker Bay in 2011. Westpac Lifesaver Rescue Helicopter.

Despite their fearsome reputation, attacks by Sharks are relatively rare, and most  attacks on Humans by Great White Sharks are thought to be mistakes. The species feeds principally on Marine Mammals, which we superficially resemble when we enter the water, gaining the majority of their nutrition from the thick adipose (fat) layers of these animals, which we lack. Due to this, when Great Whites do attack Humans these attacks are often broken off without the victim being consumed. Such attacks frequently result in severe injuries, but are seldom immediately fatal, with victims likely to survive if they receive immediate medical attention.
The distribution of Great White Sharks around Australia. Fishes of Australia.
Despite this general rarity, Australia appears to be suffering a sharp rise in Shark attacks, with five fatal attacks so far this year, three of them in the past five weeks, as well as several non-fatal attacks, the most recent of which occurred near Fitzroy Island off the coast of Cairns in North Queensland on Tuesday 14 July. Marine biologist Julian Pepperell has suggested that this increase might be linked to a rise in the number of Humpback Whales, Megaptera novaeangliae, passing through Australian waters each year. Humpback Whales are a significant food source for many Sharks; adult Whales are beyond their hunting capacity, but do die of other causes and are enthusiastically scavenged, while larger Sharks such as Great Wights will attack Whale calves. Around 35 000 Humpback Whales currently migrate through Australian Waters each year, according to  zoologist Vanessa Pirotta of Macquarie University, a number which is growing by about 11% each year.
A Humpback Whale, Megaptera novaeangliae, off the East Coast of Australia in July 2017. ABC.

Humpback Whales were nearly exterminated by commercial Whaling in the first part of the twentieth century. The species has been protected since 1946, and in recent years their population has appeared to be recovering in many areas, now being seen as being of Least Concern  under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species. The Whales are recovering in many parts of the globe, and are starting to appear in areas where they have not previously been recorded.
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