Archive for the ‘Sharks’ Category

Sharks of the same species can have different personalities, indicates a new study published in the Journal of Fish Biology.

The study, led by Dr. Evan Byrnes of Macquarie University in North Ryde, Australia, examined interindividual personality differences between Port Jackson sharks (Heterodontus portusjacksoni).

Trials were designed to test the sharks’ boldness, which is a measure of their propensity to take risks, but also an influencer of individual health through its correlation with stress hormones and associated physiological profiles.

Port Jackson sharks were first introduced to a tank where they were provided with shelter, and timed to see how long it took for each shark to emerge from their refuge box into a new environment.

The second behavior test exposed each shark to handling stress, similar to handling by a fisherman, before releasing them again and observing how quickly they recovered.

The results demonstrated that each shark’s behavior was consistent over repeated trials, indicating ingrained behaviors rather than chance reactions.

That is, some sharks were consistently bolder than others, and the sharks that were the most reactive to handling stress in the first trial were also the most reactive in a second trial.

“This work shows that we cannot think of all sharks as the same,” Dr. Byrnes said.

“Each has its own preferences and behaviors, and it is likely that these differences influence how individuals interact with their habitat and other species.”

“We are excited about these results because they demonstrate that sharks are not just mindless machines. Just like humans, each shark is an individual with its unique preferences and behaviors,” said co-author Dr. Culum Brown, also from Macquarie University.

“Our results raise a number of questions about individual variation in the behavior of top predators and the ecological and management implications this may have. If each shark is an individual and doing its own thing, then clearly managing shark populations is much more complicated than we previously thought.”

“Understanding how personality influences variation in shark behavior – such as prey choice, habitat use and activity levels – is critical to better managing these top predators that play important ecological roles in marine ecosystems.”

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E.E. Byrnes & C. Brown. Individual personality differences in Port Jackson sharks Heterodontus portusjacksoni. Journal of Fish Biology, published online May 26, 2016; doi: 10.1111/jfb.12993

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By Henry Hanks

It’s not often that someone discovers a new species, especially when it’s been under their nose for years.

A shark collected during a research expedition in 2010 turns out to be a ninja lanternshark, a brand new species of shark, so named because it is all black, which is how a ninja is typically dressed.

The scientific name is Etmopterus benchleyi, a reference to “Jaws” author Peter Benchley.

Grad student Vicky Vasquez and Dr. Douglas J. Long wrote about their findings after being asked to take a closer look at the shark (along with her professor, Dr. David A. Ebert of the Pacific Shark Research Center at Cal State).

“It is also the first lanternshark to ever be discovered off of the central eastern Pacific Ocean near Central America,” Vasquez pointed o

Four children, ages 8 to 14 years old, decided upon the name “ninja lanternshark.”

http://www.cnn.com/2015/12/24/us/shark-discovery-feat/index.html

Brennan Phillips and some colleagues were recently on an expedition to Kavachi volcano, an active underwater volcano near the Solomon Islands in the South Pacific. But they weren’t prepared for what they saw deep inside the volcanic crater:

Sharks!

Hammerheads and silky sharks, to be specific, contentedly swimming around despite the sizzling water temperatures and biting acidity.

Volcanic vents such as these can release fluids above 800 degrees Fahrenheit and have a similar acidity to vinegar, according to the Marine Education Society of Australasia.

“The idea of there being large animals like sharks hanging out and living inside the caldera of the volcano conflicts with what we know about Kavachi, which is that it erupts,” Phillips, a biological oceanography Ph.D. student at the University of Rhode Island.

This brings up some perplexing questions about what the animals do if the volcano decides to wake up:

“Do they leave?” Phillips asks. “Do they have some sign that it’s about to erupt? Do they blow up sky-high in little bits?”

The volcano wasn’t erupting when Phillips’ team arrived, meaning it was safe to drop an 80-pound camera into the water to take a look around. After about an hour of recording, the team fished the camera out and watched the video.

First, the video showed some jellyfish, snappers, and small fish. Then, a hammerhead swam into view, and the scientists erupted in cheers. They also saw a cool-looking stingray.

http://www.businessinsider.com/sharks-found-swimming-near-active-underwater-volcano-2015-7

To understand why so many people are drawn to deadly creatures of the deep, look to the quote by the sociobiologist E.O. Wilson: “We are not afraid of predators, we’re transfixed by them … We love our monsters.”

The best example of this paradox: Even as shark attacks have spiked off the coast of the Carolinas this year, Discovery Channel’s Shark Week kicked off this weekend with the most programming hours in its history. People should be at least a little afraid of sharks, it seems, yet they can’t get enough of them.

Perhaps that explains why surfers brave shark-invested waters again and again in search of the perfect wave—and suffer some of the most gruesome shark attacks as a result. After hearing about a rash of shark attacks—five of them fatal—in Western Australia a few years ago, the kitesurfer and entrepreneur Hamish Jolly began exploring ways to protect ocean-sport enthusiasts without forcing them to get out of the water.

In a 2013 TedxPerth talk, Jolly presented the results of his research: a series of striped wetsuits that aim to confuse and deter sharks, leaving the surfer within the suit (hopefully) unharmed.

Together with the University of Western Australia neurobiologist Nathan Hart and the industrial designer Ray Smith, Jolly found that a suit with a dark panel and striped arms and legs would be best for surfers, since near the surface of the water, “being backlit and providing a silhouette is problematic,” he says. The design also makes the surfer look like a lionfish or sea eel, which sharks usually don’t eat. For SCUBA diving, Jolly’s team crafted a blue wetsuit that aims to hide the diver within the water.

In an test depicted in the Ted video above, the striped pattern seems to work when using a non-human bait. While the shark quickly attacked a rig covered in standard, black neoprene, it simply brushed past the zebra-striped canister. Human testing is “ongoing,” Jolly notes.

Other researchers haven’t been quite so bullish about the invention. In addition to sight, sharks use other senses, like smell and hearing, to find their prey.

George Burgess, the director of the Florida Program for Shark Research, told National Geographic that the striped pattern might be even more tempting than a standard wetsuit design. “That striped suit that is supposed to look like a lionfish is about as nice a thing as you can do to attract a shark, because of the contrast between dark and light,” he said.

Jolly’s company, Shark Attack Mitigation Systems (SAMS), is selling the suits for about $440, which might be a small price to pay for finishing a surfing trip with all your limbs intact. Still, a prominent caution page reads, “It is impossible for SAMS to guarantee that 100 percent of sharks will be deterred under all circumstances with the SAMS technology.” And that’s not necessarily SAMS’ fault, it suggests: “All sharks are dangerous and unpredictable creatures.”

http://www.theatlantic.com/technology/archive/2015/07/shark-attack-wetsuit/397772/?utm_source=SFFB

Brett Vercoe and his wife were on a diving trip yesterday morning when they came across the whale carcass. He said he saw at least five large sharks feeding on the dead whale.

“In a short period, we saw a number of sharks circling around [the whale],” he said. “After 10 or 15 minutes it was quite obvious there were at least five sharks – three white pointers, up to about 4.5 metres in length, and two tigers, the biggest being about 4.2 [metres long].

“[It was] a very impressive display as they casually moved in and just took large bites out of the dead sperm whale.”

Mr Vercoe said it was a rewarding experience. “It was incredible to find that happening just five or 10 kilometres from Coffs Harbour. Unbelievable. It was a really exciting time,” he said.

The whale carcass later washed up on shore.

“She had obviously drifted over quite a distance,” Mr Vercoe said. “Normally their habitat’s about 40 kilometres off-shore. So, to find her only 500 metres off the beach, she’d obviously been adrift for quite some time. She’d been dead for at least a week I imagine for her state.”

Shark Loses a Tooth

A photographer off South Africa recently captured the moment a large great white shark breached the surface during an ambush attack on an unsuspecting seal.

What he soon found out was that in one of his images was a large triangular-shaped tooth, flying through the air.

Not a big deal for the shark. Great whites possess the ability to replace lost teeth rather quickly, and may lose more than 35,000 teeth in a lifetime.

But it was a huge deal for the photographer, David Jenkins, because his rare image reveals more about the dynamics of a white shark’s ambush attack.

“It all happened incredibly quickly,” he told the Daily Mail. “I didn’t know the shark had lost its tooth until I zoomed in on the image in the back of my camera to check if the photo was sharp and in focus.

“I have never seen this happen or even seen a photo of this happening on a real seal hunt before. It’s definitely a unique shot.”

The waters near Cape Town boast a large population of great white sharks, which sometimes launch airborne during their attacks.

http://www.grindtv.com/outdoor/nature/post/rare-image-shows-great-white-shark-losing-tooth-during-airborne-attack-on-seal/

Thanks to Pete Cuomo to bringing this to the attention of the It’s Interesting community.

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By Alan Yu

Sharks in Western Australia are now tweeting out where they are.

Government researchers have tagged 338 sharks with acoustic transmitters that monitor where the animals are. When a tagged shark is about half a mile away from a beach, it triggers a computer alert, which tweets out a message on the Surf Life Saving Western Australia Twitter feed. The tweet notes the shark’s size, breed and approximate location.

Since 2011, Australia has had more fatal shark attacks than any other country; there have been six over the past two years — the most recent in November.

The tagging system alerts beachgoers far quicker than traditional warnings, says Chris Peck, operations manager of Surf Life Saving Western Australia. “Now it’s instant information,” he tells Sky News, “and really people don’t have an excuse to say we’re not getting the information. It’s about whether you are searching for it and finding it.”

The tags will also be monitored by scientists studying the sharks. Researchers have tagged great whites, whaler sharks and tiger sharks.

“This kind of innovative thinking is exactly what we need more of when it comes to finding solutions to human-wildlife conflict,” says Alison Kock, research manager of the Shark Spotters program in South Africa. Kock tells NPR that the project is a good idea — but that people should know that not all sharks are tagged.

Her program does the same work, but humans do the spotting and tweeting.

Kock and Kim Holland, a marine biologist who leads shark research at the University of Hawaii, agree that the tweets won’t be enough to protect swimmers.

“It can, in fact, provide a false sense of security — that is, if there is no tweet, then there is no danger — and that simply is not a reasonable interpretation,” Holland says, pointing out that the reverse is also true. “Just because there’s a shark nearby doesn’t mean to say that there’s any danger. In Hawaii, tiger sharks are all around our coastlines all the time, and yet we have very, very few attacks.”

In Western Australia, the local government recently proposed a plan to bait and kill sharks that swim near beaches.

Holland says most shark biologists would agree that’s not a good plan, partly because of what researchers have learned using acoustic transmitters. Scientists tracking white sharks, for example, found that the species can travel great distances, going from Western Australia to South Africa in some cases.

“Because we know that they are so mobile, we’re not sure that killing any of them will have any effect on safety,” Holland says, pointing out that great white sharks don’t set up shop along the same coastlines for long. He says the number of these sharks is on the rise — but there aren’t that many to begin with.

“The other side of the coin is that it’s a horrible thing to see when people get killed, so there’s often public outcry for government agencies to do something.”

http://www.npr.org/blogs/alltechconsidered/2013/12/31/258670211/more-than-300-sharks-in-australia-are-now-on-twitter?ft=1&f=1001