Chance to track tagged sharks online

The movements of oceanic whitetip and tiger sharks tagged in the Cayman Islands and tracked by satellite can be viewed online as part of an Atlantic-wide project to fuel research on shark movements.

Five sharks tagged in waters off the Cayman Islands form part of the pan-Atlantic project, led by the Guy Harvey Research Unit.

The movements of more than 50 sharks, including tigers, sand tigers, makos and oceanic whitetips, can be viewed at the project website.

Of those, 18 sharks are still providing live data, allowing enthusiasts to follow their progress through the Atlantic on a day-to-day basis.

The five Cayman sharks have stopped providing data, because the batteries on their tags have run out.

The project leaders hope more oceanic whitetip sharks can be tagged next time there is a big game fishing tournament in Cayman.

The information from the tagged tiger sharks is already exciting researchers and will go toward three separate scientific papers to be published later this year.

The interactive map shows a web of zig-zagging lines, charting the movements of the tiger sharks. Some roam over vast distances, others, like the ones found near the Cayman Islands, appear to forage in a much smaller area.

Mahmood Shivji, director of Nova Southeastern University’s Guy Harvey Research Institute, said: “We are finding very different types of behaviour from sharks tagged at different locations.”

He said sharks tagged in Bermuda seemed to roam the open ocean, moving south to the Caribbean when the water temperatures dipped.

Others tagged in the Bahamas, and to a lesser degree in Cayman, stayed much more local to their ‘home’ islands.

Mr. Shivji said the most telling research came from around 20 tiger sharks tagged in Bermuda. One of those sharks was tracked for more than three years, enabling the research team to draw reliable conclusions about its movement patterns, which ranged from the far northern Atlantic to south of Jamaica.

“In the summer, they are acting like reef sharks, hanging on coral reefs in the Caribbean. In the winter, they are out in the deep blue in the middle of the Atlantic. We are not aware of any other shark that has that range of habitats, with the possible exception of Great Whites in the Pacific.”

The oceanic whitetip project is still in its infancy. Tracks from six sharks, tagged this year in the Bahamas, are adding to information from two sharks tagged in Cayman in 2011, named Chris and Stella by researchers.

“Guy Harvey is very interested in expanding our work in Cayman on oceanic whitetips,” Mr. Shivji said.

What is clear from the data is that sharks do not respect international boundaries.

Makos tagged in Mexico have turned up near the Cayman Islands, one of the oceanic whitetips tagged here was last recorded off the coast of Dominica, sharks tagged in Bermuda have turned up in Puerto Rico.

“We always suspected that would be the case, but we now have evidence to put on the table and say, here it is, this is a conservation issue that has to be managed on a multi-national level,” Mr. Shivji said.

Track a shark at 
www.nova.edu/ocean/ghri/tracking