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

 

Fishing threatens rare dolphins in tourist hotspot

Fishing threatens rare dolphins in tourist hotspot: Otago study
Friday 5 July 2013

New research by University of Otago scientists has shown that the Hector’s dolphin, an endangered species found only in New Zealand, is more at risk from amateur fishing in Akaroa Harbour than had been thought.

Akaroa harbour is the largest harbour on Banks Peninsula, near Christchurch. It is home to a valuable dolphin-watching industry, which takes visitors to see and swim with Hector’s dolphins.

The team, comprising dolphin experts Professor Steve Dawson, Associate Professor Liz Slooten, and statistician Associate Professor David Fletcher, moored three “T-POD” acoustic devices in the inner, middle and outer parts of Akaroa Harbour. The devices logged the high-frequency echo-location signals of Hector’s dolphins over an entire year.

“Because Hector’s dolphin echo-location clicks are very different from those of other dolphins in New Zealand, we can tune the T-PODs to detect them specifically,” Prof Dawson said.

He says previously it was thought that Hector’s dolphins were present in the inner harbour only in summer.

“Because of this, amateur fishers were given a concession allowing them to set unattended set nets in this area for seven months of the year (1 April - 30 September). The nets, made of nylon mesh, can entangle dolphins and prevent them from surfacing for air,” he says.
The devices have a small detection radius, of about 200 metres. Despite this representing less than 1% of the inner harbour area, Hector’s dolphins were detected on 41% of the days during the recreational fishing concession period when set nets could be used.

“This shows that dolphins use this area much more regularly that previously thought, and that the concession offered to amateur gillnetters is not safe for the dolphins,”  he says.

“A crucial problem for Hector’s dolphins is that in several key areas the protection does not match the dolphins’ distribution. The new research shows this is true in Akaroa Harbour, but it is also true offshore around Banks Peninsula, where aerial surveys have shown that the dolphins range much further offshore than the protection extends. A large part of that population is essentially unprotected.”

The research also revealed how the dolphins use the harbour varies with location, season, time of day and tide. The research was published yesterday in the scientific journal Endangered Species Research.
http://www.int-res.com/abstracts/esr/v21/n1/

ENDS

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Auckland Port To Recapture Gas: Union Calls On Ports To Stop Spewing Methyl Bromide

The Maritime Union of New Zealand welcomes the decision by Ports of Auckland to stop releasing methyl bromide emissions into the air. The move to fully recapture the toxic gas after fumigation sets a new benchmark for industry best practice. More>>

ALSO:

Retail: Banks Shoes Calls In Receiver

Banks Group, which runs 14 stores across the country under the brands including Banks Shoes and Shoe Connection, has been tipped into receivership at the request of director John Bank. More>>

ALSO:

NZ's Space Programme: Rocket Lab Makes It To Space (But Not Orbit)

Electron lifted-off at 16:20 NZST from Rocket Lab Launch Complex 1 on the Mahia Peninsula in New Zealand. It was the first orbital-class rocket launched from from a private launch site in the world. More>>

ALSO:

Earlier:

Budget: Irrigate (Good Times, Come On!)

Additional grant funding of $26.7 million over the next three years plus a capital boost of $63 million towards irrigation investments in Budget 2017 will deliver economic and environmental benefits through better use of water... More>>

ALSO:

Silver Fern Farms: Proposal To Close Fairton Sheepmeat Plant

Silver Fern Farms has advised its people of the proposal to permanently close the site, and has discussed potential transfer options to its other sites in the region as part of the consultation process...
More>>

ALSO: