Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search


Kiwi great whites cross the ditch to Bondi

NIWA Media Release Embargoed until 5am 25 September 2012

Kiwi great whites cross the ditch to Bondi

Recently, Australian and New Caledonian shark scientists downloaded data from acoustic receivers deployed off the east coast of Australia and in the Coral Sea and discovered that great white sharks acoustically tagged in New Zealand had been visiting.

Great white sharks leave our shores during winter, in June or July, and swim all the way to tropical waters such as Tonga, New Caledonia and the Great Barrier Reef.

There are seven receivers set up at the Chesterfield Reefs in the Coral Sea. These receivers detect acoustically tagged sharks as they travel past them. An unnamed great white male shark, 3.3 metres long, was tagged at Stewart Island in March 2011 and then detected at Chesterfield Reefs in October 2011. Previously, great white sharks tagged with pop-up tags had visited the same area.

“Ella, a 4.4 metre-long great white shark was tracked from Stewart Island to New Caledonia in both 2009 and 2011,” says NIWA Principal Scientist Dr Malcolm Francis. Another big great white shark, Phred, who is 4.8 metres long, was also tracked to Chesterfield Reefs in 2009.

There are 46 acoustic receivers off Sydney in Australia. Thirty-six of these are arranged in a line from just off Bondi Beach out to the edge of the continental shelf.

Australian scientists recently recorded a New Zealand great white shark, tagged by NIWA and Department of Conservation (DoC) at Stewart Island in March 2011, on their receivers.
“In February 2012 a 2.8 metre-long shark known as Meadsy was picked up on a receiver 10 kilometres off Bondi Beach,” says Dr Francis. “It was picked up again at Stewart Island in March 2012 by our receiver array, having crossed the Tasman Sea in 21 days at an average speed of 96 kilometres per day.”

“The detection of our great white sharks by receivers deployed elsewhere in the southwest Pacific is a strong endorsement of the benefits of international cooperation among shark researchers,” says Dr Francis.

In 2011, scientists tagged 25 great white sharks with acoustic tags and two with pop up tags on the Titi (Muttonbird) Islands off the northeast coast of Stewart Island. In 2012, they tagged 20 great white sharks with acoustic tags and five with pop up tags in the same area.

A recent download of the Stewart Island receivers has provided a second year of data on the local movements, times of departure, and arrival of great white sharks in the area.

Last year, the sharks left our shores at the end of June and started coming back between December and May. Many of the same white sharks are seen every year at Stewart Island, indicating an amazing ability to navigate back to the same spot after travelling thousands of kilometres across open ocean.

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

“The tags and photo identifications help build a detailed picture of where they hang out, for how long and when they are there,” says DoC scientist Clinton Duffy.

The tracking project is a collaboration between NIWA, DoC and Auckland University scientists. This research is funded mainly by the Ministry of Business, Innovation and Employment (MBIE), DoC, and NIWA.

The scientists working on the great white shark tracking project have also recently tagged a mako shark, Carol, who is 1.8 metres long, with a satellite-transmitting tag on her dorsal fin.

"Carol was tagged in May 2012, at the Bay of Islands, and she headed off halfway towards Fiji. She then came back to Ninety Mile Beach in Northland, where she spent six weeks, and then set off for Fiji again. She arrived off the Yasawa Islands last week having travelled 1900 kilometres in 28 days. Since she was tagged, Carol has swum nearly 6400 kilometres in 111 days, at an average of 58 kilometres per day."

This mako-tagging work was co-funded by US collaborator, Professor Mahmood Shivji from the Guy Harvey Research Institute at the Nova Southeastern University Oceanographic Center in Florida, and the Ministry for Primary Industries.

© Scoop Media

Business Headlines | Sci-Tech Headlines


DIY: Kiwi Ingenuity And Masking Tape Saves Chick

Kiwi ingenuity and masking tape has saved a Kiwi chick after its egg was badly damaged endangering the chick's life. The egg was delivered to Kiwi Encounter at Rainbow Springs in Rotorua 14 days ago by a DOC worker with a large hole in its shell and against all odds has just successfully hatched. More>>


Trade: Key To Lead Mission To India; ASEAN FTA Review Announced

Prime Minister John Key will lead a trade delegation to India next week, saying the pursuit of a free trade agreement with the protectionist giant is "the primary reason we're going" but playing down the likelihood of early progress. More>>



MYOB: Digital Signatures Go Live

From today, Inland Revenue will begin accepting “digital signatures”, saving businesses and their accountants a huge amount of administration time and further reducing the need for pen and paper in the workplace. More>>

Oil Searches: Norway's Statoil Quits Reinga Basin

Statoil, the Norwegian state-owned oil company, has given up oil and gas exploration in Northland's Reinga Basin, saying the probably of a find was 'too low'. More>>


Modern Living: Auckland Development Blowouts Reminiscent Of Run Up To GFC

The collapse of property developments in Auckland is "almost groundhog day" to the run-up of the global financial crisis in 2007/2008 as banks refuse to fund projects due to blowouts in construction and labour costs, says John Kensington, the author of KPMG's Financial Institutions Performance Survey. More>>


Health: New Zealand's First ‘No Sugary Drinks’ Logo Unveiled

New Zealand’s first “no sugary drinks logo” has been unveiled at an event in Wellington... It will empower communities around New Zealand to lift their health and wellbeing and send a clear message about the damage caused by too much sugar in our diets. More>>


Get More From Scoop

Search Scoop  
Powered by Vodafone
NZ independent news