Forwarded from "J.W. Broekema" <[EMAIL PROTECTED]>
Date: Mon, 7 Jul 2003 23:38:25 +0200
This is the final statement by the Council of the European Cetacean
Society, based on the request of the ECS membership at the 2002 Annual
Conference at Las Palmas de Gran Canaria. The statement and more info
on the ECS can be found at the ECS web site.
Marine mammals are acoustically diverse and present wide variations
not only in ear anatomy, but also in hearing range and
sensitivity. Cetacean middle and inner ears are structurally modified
from those of terrestrial mammals in ways that accommodate rapid
pressure changes. The same adaptations may, perhaps, provide
protective mechanisms that lessen the risk of injury from acoustic
impact, but no behavioural or psychometric studies are available to
support or even address this issue.
Given the fact that marine mammals depend on sound for all aspects of
their life, there is no doubt that they are extremely vulnerable to
man-made, underwater noise. In light of an alarming recent increase in
mortality events, it is becoming clear that man-made noise, at
different intensity levels, negatively affects cetacean populations in
important ways (17th European Cetacean Society Conference, Las Palmas
de Gran Canaria, March 2003: "Marine Mammals and Sound"). This
includes, for example, the animals'displacement, avoidance reactions,
collision with ships, stranding and death.
Evidence is particularly strong that high intensity active sonar, and
probably other loud noise sources, like those from shipping, gas
exploration, seismic surveys, etc., cause lesions in acoustic organs
which are severe enough to be lethal. The same sources may also
produce behaviours that cause acute lesions which eventually lead the
animals to strand and die (Active Sonar Workshop, 17th ECS Conference,
The current scientific knowledge on the effects of noise on marine
mammals and their habitat is insufficient to understand the
relationships of frequencies, intensities, and duration of exposures
that produce injury.
In the face of this uncertainty, the European Cetacean Society Council
1 Research on the effects of man-made noise on marine mammals is
urgently needed and must be conducted to the highest standards of
scientific and public credibility, avoiding all conflicts of interest;
2 Non-invasive mitigation measures must be developed and
3 In areas of cetacean concentration, the use of underwater powerful
noise sources should be limited until their short- and long-term
effects on marine mammals are understood and can be taken into
Objective parameters must be designed to assess the conservation of
marine biodiversity and to help implement national and European
policies on marine noise pollution.
European Cetacean Society <a href="http://www.broekemaweb.nl/ecs"
Jan Willem Broekema
Member of Council, web manager
<a href="[EMAIL" rel="nofollow">[EMAIL</a> PROTECTED]