New Irish research reveals the secret lives of tiger sharks

JUNE 7, 2019

by Thomas Deane, Trinity College Dublin

A team of scientists led by experts from Trinity and a US-based NGO have just returned from the Bahamas where they learned all about the secret lives of the region's tiger sharks.

Cutting-edge bio-logging devices fixed to the sharks are providing a suite of biological information that has never been collected before, which will help the team assess how the global climate crisis may impact these apex predators.

Tiger sharks are classified as 'near threatened' by the International Union for the Conservation of Nature, with commercial and artisanal fishing pressure and infrequent (once every three years) reproduction contributing to this status. Several countries continue to cull populations of tiger sharks given perceived risks to human swimmers, despite some regions having seen declines in shark abundance of ~ 75% in recent decades.

These huge (up to 5m in length) animals are found in tropical and sub-tropical oceans worldwide but have always been difficult to study given their aquatic lifestyle. The scientists involved in the current study got around this issue by using their biologging devices on the sharks—with sensors recording video, body temperature, swimming activity and orientation as the animals went about their normal routine.

By measuring how temperature influences the sharks' behaviour and swimming performance, the team will be better placed to predict how these animals will respond to future climate change.

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This Beached Shark Tore a Beached Whale to Shreds (And It's All on Video)

By Brandon Specktor, Senior Writer | October 2, 2018 12:32pm ET

When a beached whale arrives on your local shore, it's sad, but not too surprising. When a live, thrashing tiger shark arrives right next to it, it's a good time to dust off your favorite expletives.

That's what some Ponta, Mozambique residents did when they saw a massive, 13-foot-long (4 meters) tiger shark (Galeocerdo cuvier) seemingly beach itself in order to chow down on the 30-ton humpback whale carcass bedecking the local shore.

According to Lorrayne Gaymer, a Mozambique dive instructor who filmed the incident (and the community's shocked response), the 66,000-lb. (30,000 kilograms) whale washed up on Ponta beach in early September. [13 Bizarre Things That Washed Up On Beaches]

"Initially, a rescue attempt was made for the whale, but after the locals of Ponta contacted a whale expert it became clear that the whale was very sick and shouldn't be moved," Gaymer told The Daily Mail. "It had passed away, and as the tide went out, hundreds of locals of Ponta all came down to take their share."

Then, Gaymer said, the sharks descended. According to Caters New Agency, an estimated 60 sharks of different species — including tiger, bulland dusky sharks — took turns ripping hunks of meat and blubber out of the whale's side. By the time Gaymer arrived on the scene and started filming, one giant tiger shark had swum so close to shore that it temporarily beached itself on the sand near the whale.

As you can intuit from the sundry shrieks and bleeped-out expletives that begin Gaymer's video, the sight of a tiger shark so close to shore was both exciting and terrifying for many spectators.

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Tagged tiger shark proving unstoppable

Date:  January 11, 2018

Source:  Nova Southeastern University

Summary:

For more than a decade, researchers have been tagging and tracking sharks in order to study their migratory patterns and more. One tiger shark - Andy - is now the longest-ever tracked tiger shark, providing years worth of data for researchers.

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Longest tiger shark tracking reveals bird-like migration

June 10, 2015

Brett Smith for redOrbit.com – Your Universe Online

Using the first-ever continuous, multiple year satellite tagging program, marine biologists have found that tiger sharks routinely perform a bird-like seasonal migration – from the tropical waters of the Caribbean all the way up to the more temperate waters of the mid-North Atlantic.

A new study on the research, published in the journal Scientific Reports, could have major implications for the conservation of tiger sharks.

“As apex predators, the presence of tiger sharks — and other large sharks — is vital to maintain the proper health and balance of our oceans, Mahmood Shivji, a shark expert at Florida’s Nova Southeastern University and study author, said in a press release. “That’s why it’s so important to conserve them, and understanding their migratory behavior is essential to achieving this goal.”

Due to insufficient tagging technology and logistical concerns, researchers haven’t been able to effectively track tiger sharks for long periods in the past. The new research project saw researchers tracking the animals for three years or more in some cases. One particular shark, called Harry Lindo, was followed for more than 27,000 miles – which could be the longest distant a shark has ever been tracked, the researchers said.

The scientists were able to reveal that adult male tiger sharks in the Atlantic consistently spend their winters in Caribbean island locations. During the summers, the tiger sharks travel far into the North Atlantic, occasionally as far north as Connecticut. East Coast swimmers needn’t worry though, as the sharks stay well offshore.

“These repeated journeys were very unexpected,” said study author James Lea, a marine biologist from The Marine Biological Association in the United Kingdom. “The tiger shark has traditionally been considered a coastal species, and it is rare among sharks to so easily and habitually switch between the two vastly different environments.

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Texas fisherman catches 809-pound tiger shark

18 hours ago

6th August 2014

PORT ARANSAS, Texas (AP) — A Texas fisherman has landed an 809-pound tiger shark in the Gulf of Mexico after reeling it in for more than seven hours.

Ryan Spring of San Antonio says he caught the shark Sunday about 5 miles off Port Aransas (uh-RAN'-suhs). He says the 12-foot, 7-inch shark was about as big as his boat. He says it pulled the vessel south for more than 15 miles.

It took about a dozen men to haul the male shark onto the dock. Spring plans to donate meat from the shark to charity.

The catch falls short of the tiger shark state record, which according to the Texas Parks and Wildlife Department says is 1,129 pounds.

Source

Surfer Fends Off Shark With Punches To Head

A surfer in Hawaii has survived being attacked by a shark after grabbing its fin and repeatedly punching the fish in the head.

Jeff Horton, 25, was surfing near Kilauea when a fin was spotted in the water.

Twenty minutes later, he was sitting on his surfboard with his legs dangling in the water when he spotted a dark shape approaching.

Initially he thought it was a stingray, but was forced to quickly pull his legs out of the water as the tiger shark bit into his surfboard.

The impact knocked Mr Horton off his board and on top of the shark.

Holding on to the shark with one hand, he repeatedly punched it as hard as he could.

He said: "I finally got one nice punch into the eye. I put some really good hits on it, for sure."

It was only after his knuckle jammed into the shark's eye that it spat out his surfboard and swam away.

Mr Horton was able to scramble back on to his board and, along with another surfer, paddled to the shore as the shark briefly followed behind them.

His 7ft board, which has a teeth imprint, will now be put up on his wall.

http://uk.news.yahoo.com/surfer-fends-off-shark-punches-face-195228466.html#thXVugr

Massive Tiger Shark Caught On Texas Beach

An angler spent a gruelling three and a half hours reeling in his biggest catch ever - a 12ft tiger shark.

Wayne Wimer caught the creature from the Gulf of Mexico, just south of the Packery Channel, on South Padre Island, near to Corpus Christi, Texas.

The shark was so strong and heavy, he was unable to haul it in himself and had to get a team of other anglers who were nearby to help him.

At one point Mr Wimer was so exhausted someone had to bring him a chair so he could carry on.

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