For the first time, great white sharks in New Zealand waters have been outfitted with satellite tags, researchers said today. The devices will help scientists learn where and how deep the creatures go.
Four sharks were tagged in the project with devices that collect detailed information about the depth, temperature, and light levels of water through which they travel. After a few months, the tags will detach from the sharks on pre-determined dates and float to the surface, where they'll broadcast data back to ground stations via satellite.
Researchers will combine the data with genetic information to study whether New Zealand's great whites are interrelated to other populations. The project will also help scientists better understand threats to the sharks.
"An important first step in the conservation and management of any species is to identify critical habitats and migration routes," said Clinton Duffy of the New Zealand Department of Conservation. "White sharks are difficult to study due to their naturally low abundance, large size and mobility. This technology provides us with a window into their lives for the first time."
Scientists have tagged great whites off South Africa, Australia and elsewhere in recent years. Last month, a great white that killed two other aquarium sharks in California was tagged and released back into the ocean.
Great whites can reach 21 feet (6.5 meters) in length. Their reputation as a maneater is undeserved, scientists say. Most attacks occur when the sharks confuse humans with their preferred prey, including sea lions and seals.
Game fishing and commercial fin harvesting have put the great white's survival at risk, experts believe, though there are no exact figures on regional or worldwide populations of the beasts.
The new project is supported by the U.S.-based Wildlife Conservation Society (WCS).
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Shark Attacks on Humans
Just a dozen shark attacks occurred in Florida in 2004, compared to 30 in 2003, 29 in 2002, 34 in 2001, and 37 in 2000. The deadly series of four hurricanes in the 2004 summer meant fewer people were in the water, but sharks are known to head for deep water when a hurricane approaches.
Globally, there were 61 unprovoked shark attacks in 2004, according to The International Shark Attack File at the Florida Museum of Natural History. Seven people died. There were also 15 provoked attacks (typically a diver bit after grabbing a shark or a fisherman bit while removing a shark from a net) and 12 cases of sharks biting boats. The global total was down slightly from recent years but still part of an upward trend overall.
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