- Deafening sonar booms are giving whales and dolphins
fatal doses of the bends, according to research.
- Scientists believe they may be startled by the sound
from submarines and forced to ascend too quickly. Researchers have shown
for the first time that deep diving marine animals can suffer from decompression
sickness - a potentially deadly condition experienced by divers who resurface
- They are calling for more research into the dangers of
sonar and tighter controls on its use.
- Post mortem examinations on 14 whales stranded during
a naval exercise in the Canaries last year revealed bubbles of gas in their
blood and holes in their internal organs - symptoms of the condition. Tests
on dolphins and whales stranded on Britain's coasts over the past decade
have revealed similar damage.
- A team at the Zoological Society of London and the University
of Las Palmas, Gran Canaria, studied beaked whales and Risso's dolphins
stranded on Britain's coasts between 1992 and 2003.
- Dr Paul Jepson, from the society's UK Marine Stranding
Project, who reported the findings in Nature, said: "We discovered
that a small number of stranded animals had gas bubbles and associated
- "Although decompression sickness was previously
unheard of in marine animals, we concluded that a form of marine animal
decompression sickness was the most likely cause.
- "This new evidence from our study of marine mammal
diseases in the UK challenges the widely held notion that cetaceans (whales
and dolphins) cannot suffer from decompression sickness."
- The link with sonar emerged when 14 beaked whales were
stranded in the Canary Islands four hours after a Spanish-led naval exercise
in September 2002. Ships in the area were using mid frequency sonar. The
exercise ended when the stranded whales were discovered.
- Post mortem examinations of 10 whales revealed more evidence
of the bends.
- © Copyright of Telegraph Group Limited 2003.