|12 September 2002||
Loughborough innovation prevents fishing net deaths of dolphins and porpoises
Loughborough University researchers
in co-operation with Aquatec Subsea Ltd are at the forefront of research
to halt the decline in the worlds population of dolphins and porpoises.
Dolphins and porpoises are known to
respond to ultrasound, they use high frequency sounds to communicate and
to hunt their prey. However dangers such as static fishing nets are virtually
undetectable to their sonar sense and often have fatal consequences.
Loughborough Universitys Underwater Acoustic Research Group and
Aquatec Subsea Ltd have developed AQUAmark, a series of high tech acoustic
warning devices which have now been shown in commercial fisheries to be
very effective in saving marine mammal lives.
When activated by immersion in seawater,
the AQUAmark pingers transmit a complex series of pre-programmed acoustic
signals, comparable or less than the sound intensities produced by the
marine mammals themselves. These signals act as a warning, repelling the
mammals from fishing nets, and at close range can actively mask echoes
from the fish they may be targeting with their sonar.
Dave Goodson, Chief Experimental Officer
at Loughborough University, and part of the team working on AQUAmark commented,
Our aim has been to significantly reduce and if possible eliminate
the risks to marine mammals of fishing nets. He continued, This
is a significant problem that the fishing industry wants to solve but
where traditional approaches have been ineffective. The digital technology
we have developed is electro-acoustically very efficient and the randomly
timed wideband warning signals we chose were selected only after detailed
studies of porpoise and dolphin behaviour. AQUAmark is not only effective
as a porpoise deterrent but offers a much longer operating life and includes
management features which are not possible with analogue technology traditionally
used in pingers introduced in the USA.
One of AQUAmarks biggest successes
has been in Denmark where after very thorough testing new regulations
were introduced two years ago that required this pinger to be used in
the North Sea wreck net fishery for cod. So far the protection provided
has been 100% successful and no porpoises have been killed in the nets
equipped with AQUAmark devices. Further successful trials took place in
the French Mediterranean in 2001 where an AQUAmark device adapted for
use with dolphins produced an impressive reduction of 87.3% in the number
of dolphins caught.
Recent press reports have focused on
the large numbers of dolphin carcasses being washed up on the English
Channel coastline, which are believed to be linked to pair-pelagic trawlers
targeting sea bass. The Loughborough team, together with European partners
from Holland, France, Denmark and Sweden, have investigated dolphin behaviour
around pelagic trawls and found that dolphins and other small sea mammals
are attracted to these nets, often deliberately swimming inside the mouth
of the structure to prey on fish as they gather there.
As a result of these Loughborough studies,
the Irish Sea Fisheries Board, commissioned the consultancy services of
Loughborough University Enterprises Ltd. and Aquatec to develop a remotely
controlled research tool to help solve a perceived problem in the Irish
pair-pelagic fishery for Albacore tuna. Incidental catches of dolphins
and porpoises can occur in this fishery which operates along the continental
shelf edge between Spain and Ireland. The experimental system was recently
delivered and the current trials are examining the effectiveness of this,
together with the use of standard AQUAmark devices in this more difficult
Andy Smerdon of Aquatec concludes,
We expect to continue our previous successes with this project,
our development work is ongoing and working with Loughborough we now have
the technology and the expertise to tackle new fishery/marine mammal interaction
problems as they occur.
For further information
Notes to editors
1. The Danish Institute for Fisheries
Research commissioned a large-scale trial of the Loughborough deterrent
during 1997 and the results showed a highly significant reduction in harbour
porpoise bycatch on nets fitted with the pre-production acoustic device.
The positive outcome just one animal caught in a net equipped with
deterrents although 23 were killed in nearby unprotected nets during the
study prompted a Danish regulation requiring the use of such acoustic
deterrents on all wreck nets (one type of gillnet) from August to October.
One thousand AQUAmark 100 devices were supplied to Denmark in 2000, when
the regulation came into force. Since then, not one porpoise has been
reported caught in these nets, although statistics had predicted that
415 animals should have died in this period.
2. The preliminary trials in the French
Mediterranean Thonaille fishery using AQUAmark 200, a lower
frequency device adapted for use with dolphins, showed an 87.3% reduction
in the number of dolphins caught, and a further 1600 devices were subsequently
purchased to support an extended study involving the whole fleet. Similar
benefits are now being reported in Greece, Sicily and in other Mediterranean
countries where the devices are being deployed to help artisanal fishermen
reduce the frequent damaging attacks on their nets by dolphins.
4. Pair-pelagic trawls are large fishing nets towed by a pair of fishing vessels in order to catch fish swimming in mid-water or near to the surface.
5.. Loughborough has an established reputation for excellence in teaching and research, strong links with industry, and unrivalled sporting achievement. Assessments of teaching quality by the Quality Assurance Agency place Loughborough in the top flight of UK universities, and industry highlights Loughborough in its top five for graduate recruitment. Around 30% of the Universitys income is for research. The University has been awarded three Queens Anniversary Prizes: for its collaboration with aerospace and automotive companies such as BAE Systems, Ford and Rolls Royce; for its work in developing countries; and for pioneering research in optical engineering.
S.P.Rowbottom@lboro.ac.uk, September 2002 Copyright © Loughborough University Publicity Office. All rights reserved.