2005 Press Releases
Major International Survey of Whales, Dolphins and Porpoises
Throughout the month of July, seven ships and three aircraft will be
conducting an intensive survey of the European Atlantic continental
shelf to map the distribution and estimate the abundance of the whales,
dolphins and porpoises, collectively know as cetaceans, that live in
these waters. The survey is part of the SCANS-II project (Small
Cetaceans of the European Atlantic and North Sea) supported by the
European Commission LIFE Nature programme and 12 European governments.
SCANS-II is coordinated by the Sea Mammal Research Unit (SMRU) at the
University of St Andrews in Scotland and involves researchers from all
over western Europe, including three from University College
Cork. Two survey vessels will operate in Irish waters, covering
the western seaboard and Celtic Sea. The Irish Sea and coastal
waters will be surveyed by air plane.
The survey will determine the numbers of different species of cetaceans
in European Atlantic waters, which will be compared with numbers
obtained from a similar survey (called SCANS) conducted in 1994, also
with LIFE Nature and European government support and also coordinated
by the SMRU. These numbers are needed to assess the sustainability, or
otherwise, of the numbers of cetaceans killed incidentally in fishing
gear (know as bycatch), a particular problem for the harbour porpoise
in European continental shelf waters. Other aims of SCANS-II are to
develop cost-effective monitoring methods for cetaceans in these waters
and to develop a management framework for assessing the impact of
bycatch and determining safe bycatch limits.
The results of the survey will be presented to the European Commission
and to the participating governments in 2006. The aim is that the new
information will help to minimise the impact of cetacean bycatch in
European waters and to ensure that populations of whales, dolphins and
porpoises remain in a healthy state.
METHODS
The surveys will use line transect sampling methods, which use data on
sighted animals and the amount of time spent searching for them to
estimate abundance. Conventional line transect methods assume that all
animals directly on the transect line are detected. Because cetaceans
may be underwater when the ship or aircraft passes by, this assumption
is violated. Consequently, enhanced methods are used to collect data
that allow this problem to be overcome. These enhanced methods also
allow any movement of animals in response to the survey ships to be
accounted for.
In addition, each ship has acoustic equipment that will record the
sounds made by some cetacean species. The sounds are picked up by a
hydrophone towed 200 metres behind the vessel and relayed to computers
onboard. These data will be compared with the sightings data to assess
the value of using acoustic data for monitoring purposes.
Each ship has eight cetacean observers and each aircraft has three
observers. These scientists are of many nationalities - one of the aims
of the survey is to generate a European pool of experienced observers
for future cetacean surveys. The ships will also carry seabird
observers, who will also record data on cetaceans for comparison with
the survey data.
After the survey, it will take many months to process and analyse all the data. Results are expected in the middle of next year.
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