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

 

Power Outages, Roads Close: Easter Storm Moving Down Country

The NZ Transport Agency says storm conditions at the start of the Easter break are making driving hazardous in Auckland and Northland and it advises people extreme care is needed on the regions’ state highways and roads... More>>

ALSO:

Houses (& Tobacco) Lead Inflation: CPI Up 0.3% In March Quarter

The consumers price index (CPI) rose 0.3 percent in the March 2014 quarter, Statistics New Zealand said today. Higher tobacco and housing prices were partly countered by seasonally cheaper international air fares, vegetables, and package holidays. More>>

ALSO:

Notoriously Reliable Predictions: Budget To Show Rise In Full-Time Income To 2018: English

This year’s Budget will forecast wage increases through to 2018 amounting to a $10,500 a year increase in average full time earnings over six years to $62,200 a year, says Finance Minister Bill English in a speech urging voters not to “put all of this at risk” by changing the government. More>>

ALSO:

Prices Up, Volume Down: March NZ House Sales Drop 10% As Loan Curbs Bite

New Zealand house sales dropped 10 percent in March from a year earlier as the Reserve Bank’s restrictions on low-equity mortgages continue to weigh on sales of cheaper property. More>>

ALSO:

Scoop Business: Chorus To Appeal Copper Pricing Judgment

Chorus will appeal a High Court ruling upholding the Commerce Commission’s determination setting the regulated prices on the telecommunications network operator’s copper lines. More>>

ALSO:

Earlier:

Cars: Precautionary Recalls Announced For Toyota Vehicles

Toyota advises that a number of its New Zealand vehicles are affected by a series of precautionary global recalls. Toyota New Zealand General Manager Customer Services Spencer Morris stressed that the recalls are precautionary. More>>

ALSO:

'Gardening Club': Air Freight Cartel Nets Almost $12 Million In Penalties

The High Court in Auckland has today ordered Swiss company Kuehne + Nagel International AG to pay a penalty of $3.1 million plus costs for breaches of the Commerce Act. Kuehne + Nagel’s penalty brings the total penalties ordered in this case to $11.95 million ... More>>

ALSO:

Crown Accounts: Revenue Below Projections

Core Crown tax revenue has increased by $1.9 billion (or 5.0%) compared to the same time last year. However this was $1.1 billion less than expected and is reflected across most tax types, continuing the pattern of recent months. More>>

ALSO:

Get More From Scoop

 
 
Computer Power Plus
 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news