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

 

Strike: Lyttelton Port Workers Vote To Escalate Dispute

Members of the Rail and Maritime Transport Union (RMTU) at Lyttelton Port today voted to escalate their industrial action. Around 200 RMTU members have been operating an overtime ban since 17 December and today they endorsed a series of full withdrawals of labour at the port. More>>

ALSO:

Scoop Business: NZ Dollar Falls To 3-Year Low As Investors Favour Greenback

The New Zealand dollar fell to its lowest in more than three years as investors sold euro and bought US dollars, weakening other currencies against the greenback. More>>

ALSO:

Scoop Business: NZ Govt Operating Deficit Smaller Than Expected

The New Zealand’s government’s operating deficit was smaller than expected in the first five months of the financial year as a clampdown on expenditure managed to offset a shortfall in the tax-take from last month’s forecast. More>>

ALSO:

0.8 Percent Annually:
NZ Inflation Falls Below RBNZ's Target

New Zealand's annual pace of inflation slowed to below the Reserve Bank's target band in the final three months of the year, giving governor Graeme Wheeler more room to keep the benchmark interest rate lower for longer.More>>

ALSO:

NASA, NOAA: Find 2014 Warmest Year In Modern Record

Since 1880, Earth’s average surface temperature has warmed by about 1.4 degrees Fahrenheit (0.8 degrees Celsius), a trend that is largely driven by the increase in carbon dioxide and other human emissions into the planet’s atmosphere. The majority of that warming has occurred in the past three decades. More>>

ALSO:

Scoop Business: New Zealand’s Reserve Bank Named Central Bank Of The Year

The Reserve Bank of New Zealand’s efforts to stifle house price inflation by using new policy tools has seen the institution named Central Bank of the year by Central Banking Publications, a publisher specialising in global central banking practice. More>>

ALSO:

Get More From Scoop

 
 
Standards New Zealand

Standards New Zealand
 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news