Dolphin deaths in fishing nets to be investigated through sonar detector

A A A

A new device could help to prevent vast numbers of whales, dolphins and porpoises becoming ensnared and drowning in fishing nets.

A new device could help to prevent vast numbers of whales, dolphins and porpoises becoming ensnared and drowning in fishing nets.

The new system, called T-POD, is being developed with the support of the British organisation Wildlife Trusts in an attempt to show exactly how and when the mammals meet their deaths.

The system was invented by Dr Nick Tregenza, a research fellow at Plymouth University's Institute of Marine Studies. He said: "One of the big problems is that, although it is known a lot of cetaceans are dying as a result of fisheries, we have very little idea what goes on below the surface.

"This device will give a clearer picture of the nature of this tragedy, for instance whether they are caught at any time when fishing is in progress or just at the point when the net is closed.

"It may help to identify when and where they are at risk. Knowing exactly what is happening will help the conservation movement draw up a strong case for measures to provide greater protection for marine mammals, a goal that is always going to be difficult to achieve because it will require multi-national agreement."

Whales and dolphins deliberately swim through the 40-metre-wide net openings to take the fish caught by boats.

But many pay a high price for the apparently easy pickings. An Irish observation on mid-water trawling for tuna recently found 30 dead dolphins in one haul. Observers from the Department for Environment, Food and Rural Affairs noted 53 dead dolphins from 116 bass-fishing hauls.

Throughout the whole international fishing industry this "by-catch" is huge. Conservationists estimate that in European waters alone, 10,000 harbour porpoises are killed each year in gill nets. The number of dolphins killed also runs to "thousands".

T-POD, which scans through six frequency settings each minute, is a self-contained system that logs the echo-location clicks made by porpoises and dolphins.

These mammals use sonar, sending out very short, high-pitched pulses of sound in a beam ahead of them and then listening to the echoes from everything it strikes. The sonar is so sophisticated that a dolphin can probably "see" whether another is pregnant or has fish in its stomach.

The time and duration of up to two million clicks can be recorded by T-POD and transferred to a computer where the data is interpreted.

One successful test, in Hong Kong waters, involved the use of a rig to tow the device behind a vessel two metres below the surface. It detected all porpoises within 250 metres.

Researchers are expected to find out about cetacean habitat use, interactions between dolphins and porpoises, trends in their activity levels at specific locations and their responses to possible or proposed by-catch deterrents.

News
news

Lincoln MP Karl McCartney 'denied all knowledge' of the Twitter activity

News
The author PD James, who died on 27 November 2014
people

Detective novelist who wrote Death comes to Pemberley passed away peacefully at her home, aged 94

Arts and Entertainment
Joel Edgerton, John Turturro and Christian Bale in Exodus: Gods and Kings
filmDirector said film would 'never have been financed' with ethnic minority actors in key roles
Life and Style
View of champagne glasses at a beach bar set up along the Croisette during the 66th edition of the Cannes Film Festival in Cannes on May 17, 2013
food + drink(and for now, there's a clear winner)
PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
News
Irradiated turkey and freeze dried mash potato will be on the menu this thanksgiving
video
News
Andy Murray with his girlfriend of nine years, Kim Sears who he has got engaged to
peopleWimbledon champion announces engagement to girlfriend Kim Sears
Arts and Entertainment
George Mpanga has been shortlisted for the Critics’ Choice prize
music
Arts and Entertainment
Roisin, James and Sanjay in the boardroom
tvReview: This week's failing project manager had to go
News
Ed Miliband visiting the Holocaust museum in Jerusalem. The Labour leader has spoken more openly of his heritage recently
newsAttacks on the Labour leader have coalesced around a sense that he is different, weird, a man apart. But are the barbs more sinister?
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

SThree: Trainee Recruitment Consultant

£20000 - £45000 per annum + uncapped: SThree: Key featuresA highly motivated ...

Recruitment Genius: B2B Telemarketing Consultant

£18000 - £19000 per annum: Recruitment Genius: A highly respected Telemarketin...

Recruitment Genius: Team of Female Support Workers Required - Competitive Pay

£8 per hour: Recruitment Genius: You will need to be able to follow instructio...

Recruitment Genius: Car Sales Executive - OTE £40,000

£10000 - £40000 per annum: Recruitment Genius: Due to expansion the Largest In...

Day In a Page

Cameron, Miliband and Clegg join forces for Homeless Veterans campaign

Cameron, Miliband and Clegg join forces for Homeless Veterans campaign

It's in all our interests to look after servicemen and women who fall on hard times, say party leaders
Millionaire Sol Campbell wades into wealthy backlash against Labour's mansion tax

Sol Campbell cries foul at Labour's mansion tax

The former England defender joins Myleene Klass, Griff Rhys Jones and Melvyn Bragg in criticising proposals
Nicolas Sarkozy returns: The ex-President is preparing to fight for the leadership of France's main opposition party – but will he win big enough?

Sarkozy returns

The ex-President is preparing to fight for the leadership of France's main opposition party – but will he win big enough?
Is the criticism of Ed Miliband a coded form of anti-Semitism?

Is the criticism of Miliband anti-Semitic?

Attacks on the Labour leader have coalesced around a sense that he is different, weird, a man apart. But is the criticism more sinister?
Ouija boards are the must-have gift this Christmas, fuelled by a schlock horror film

Ouija boards are the must-have festive gift

Simon Usborne explores the appeal - and mysteries - of a century-old parlour game
There's a Good Girl exhibition: How female creatives are changing the way women are portrayed in advertising

In pictures: There's a Good Girl exhibition

The new exhibition reveals how female creatives are changing the way women are portrayed in advertising
UK firm Biscuiteers is giving cookies a makeover - from advent calendars to doll's houses

UK firm Biscuiteers is giving cookies a makeover

It worked with cupcakes, doughnuts and macarons so no wonder someone decided to revamp the humble biscuit
Can SkySaga capture the Minecraft magic?

Can SkySaga capture the Minecraft magic?

It's no surprise that the building game born in Sweden in 2009 and now played by millions, has imitators keen to construct their own mega money-spinner
The King's School is way ahead of the pack when it comes to using the latest classroom technology

Staying connected: The King's School

The school in Cambridgeshire is ahead of the pack when it comes to using the latest classroom technology. Richard Garner discovers how teachers and pupils stay connected
Christmas 2014: 23 best women's perfumes

Festively fragrant: the best women's perfumes

Give a loved one a luxe fragrance this year or treat yourself to a sensual pick-me-up
Arsenal vs Borussia Dortmund: Alex Oxlade-Chamberlain celebrates century with trademark display of speed and intuition

Arsenal vs Borussia Dortmund

The Ox celebrates century with trademark display of speed and intuition
Billy Joe Saunders vs Chris Eubank Jnr: When two worlds collide

When two worlds collide

Traveller Billy Joe Saunders did not have a pampered public-school upbringing - unlike Saturday’s opponent Chris Eubank Jnr
Homeless Veterans Christmas Appeal: Drifting and forgotten - turning lives around for ex-soldiers

Homeless Veterans Christmas Appeal: Turning lives around for ex-soldiers

Our partner charities help veterans on the brink – and get them back on their feet
Putin’s far-right ambition: Think-tank reveals how Russian President is wooing – and funding – populist parties across Europe to gain influence in the EU

Putin’s far-right ambition

Think-tank reveals how Russian President is wooing – and funding – populist parties across Europe to gain influence in the EU
Tove Jansson's Moominland: What was the inspiration for Finland's most famous family?

Escape to Moominland

What was the inspiration for Finland's most famous family?