Record number of great white sharks tagged off NZ

File Photo / APN

Scientists have tagged a record 27 great white sharks off the coast of Stewart Island which they hope will help shed more light on their behaviour around the New Zealand coast line.

National Institute of Water and Atmospheric Research (Niwa), Department of Conservation (DOC), and University of Auckland scientists hope tracking information from the tags will help determine if the sharks are transient or based in New Zealand.

The researchers also want to find out when the sharks inhabited "hotspot" locations such as Stewart Island and the size of the New Zealand population of great whites.

During the three week tagging trip around the Titi (Muttonbird) Islands off the northeast coast of Stewart Island in April the researchers attracted the sharks to a boat with a berley of tuna oil and minced tuna.

When a shark was close enough, a long pole was used to stab a tag under the skin.

Niwa principal scientist Malcolm Francis said the tags would record an exciting set of data of "where each shark was and when".

"Several great white sharks tagged with popup tags in previous years have returned to Stewart Island, indicating that some sharks return to their tagging location after their tropical holidays," Dr Francis said.

"Two 4 metre female sharks, nicknamed Miranda and Ella, have been seen at the Stewart Island tagging site each year for four years," he said.

Department of Conservation scientist Clinton Duffy said the tags and photo-identifications would help build a detailed picture of "where they hang out, and how long and when they are there".

"This will provide an intriguing insight into the lives of these magnificent animals, and improve our understanding of their habitat requirements.

"We should also be able to make an estimate of the size of the population around Stewart Island from the ratio of re-sighted sharks to new, unknown animals," Mr Duffy said.

The previous tagging record for an expedition was nine sharks.

Great white sharks - which were protected in New Zealand waters in 2007 - are known to reach up to 6 metres in length and weigh up to 2268 kilograms.

- NZPA