New Zealand (Global Adventures): A great white shark tagged by the National Institute of Water & Atmospheric Research (Niwa) did dive to a depth of 3,937 feet (1,200 meters). Scientists with the New Zealand based research organization hope to gain a better understanding of the migratory patterns of the great white shark by studying its movements.
“A big shark called Shack, the biggest shark we have tagged at 4.8 meters, has set the world’s deepest great white shark dive record,” said Malcolm Francis, principal scientist at Niwa. “And he made several other very deep dive records between 1,000 and 1,200 meters while crossing the ocean. Prior to this, we had recorded several at around 1,000 meters, so it’s quite a substantial extension.”
While great white sharks have been protected in New Zealand waters since 2007,
little is known about their habitat requirements and their interactions with sharks elsewhere.
Over a five year period, New Zealand scientists tagged Shack and 24 other great white sharks with electronic “pop-up” tags at Stewart and Chatham Islands. The high-tech tag records location, depth and temperature. Also Releases itself after a pre-determined time, usually 6 to 9 months, to transmit its data via satellite, according to a Niwa press release.
Of the 25 tagged sharks,
four tags came off within the first two weeks. Movement tracks could be determined for nineteen sharks. After that Only a big female shark named Kara stayed near the tagging site for the whole time. The other 18 sharks headed towards warmer tropical waters.
“Before we started this work five years ago, it was thought that great white sharks were cold water animals. But it seems the great white sharks are taking tropical winter holidays, departing New Zealand between April and September, for somewhere warmer. The maximum distance migrated was [2,051 miles] 3300 kilometers,” said Francis. After that One shark returned to its Chatham Islands tagging site after 6 months.
After nearly a year,
the tag releases itself from the tether, floats to the ocean surface and starts sending the data via satellite. “If the tag itself is recovered after washing ashore. We are able to extract much more high resolution data from it. So far, we have recovered 6 tags from the Pacific Ocean,” said Francis.
Great white sharks make long migratory trips with frequent dive deeps. They can travel 93 miles (150 kilometers) a day. After that it takes them just three weeks to go from New Zealand to Australia. On their travel, they experience a huge range of water temperatures between 37 and 81 degrees. Sharks tagged in Australia have turned up in New Zealand waters. Also Sharks from New Zealand have been spotted off the coasts of New South Wales and Queensland, in the Coral Sea, New Caledonia, Vanuatu, Norfolk and Tonga. This suggests that the southwest Pacific may comprise a single population.
Great white sharks can exceed 20 feet (6 meters) in length and 4,940 pounds (2,240 kilograms) in weight. Also They become sexually mature at around 15 years of age and have a lifespan of 30 to over 100 years.
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