Low-frequency sonar killed whales, U.S. Navy and NMFS admit

From ANIMAL PEOPLE, January/February 2002:

WASHINGTON, D.C.–A joint report by the U.S. Navy and
National Marine Fisheries Service confirms the February 2001
allegation of Center for Whale Research founder Ken Balcomb that
sound waves from Navy sonar exercises caused 16 small toothed whales
and a spotted dolphin to beach themselves in the Bahamas in mid-March
2000.
Seven of the animals died. The other 10 were pushed back out
to sea by would-be rescuers, but are also believed to have died.

Released on December 20, 2001, rhe U.S. Navy and NMFS
report “marks the first time that underwater noise other than from an
explosion has been shown to cause fatal trauma in marine mammals,”
said Washington Post staff writer Rick Weiss. “The acknowledgement
of responsibility also marks a sharp departure from earlier
statements by the Navy,” which had denied any link between sonar
exercises and mass strandings of marine mammals.
Spokesperson Patrick McNally said the Navy would introduce
policies to prevent further injuries to whales and dolphins due to
sonar use, and would increase spending on marine mammal research to
$9 million in the next fiscal year.
The British Royal Navy announced similar but more extensive
measures in August 2001. The British Navy is reportedly to upgrade
the sonar systems of 16 frigates and eight minesweepers, at cost of
$530 million–but the retrofitting will not start until 2006.
“To the maximum extent practical, the U.S. Navy will adopt
measures in its future peacetime operations and training, including
the use of tactical mid-range sonars, to avoid injuring or harassing
marine mammals,” a joint U.S. Navy/NMFS press release said.
But the Navy response did not satisfy longtime critics of the
SURTASS-LFA sonar program and other sources of underwater noise that
may be deadly to whales.
“Beaked whales may be at risk from loud mid-to-low-frequency
sounds throughout their largely unknown distribution,” said retired
University of Calgary zoologist Paul K. Anderson. “The U.S. Navy
commitment to ameliorating the impat of powerful mid-frequency range
sonars, used by all the world’s navies, extends only ‘to the
greatest extent practicable’ in peacetime training. Naval commanders
have obligations to their governments, crews, and vessels that will
take precedence even in peacetime. In wartime, there will be no
restrictions.
“The U.S. Navy/NMFS report calls for more research. This is
not good enough,” Anderson added. “The only responsible approach is
a search for international agreements banning such powerful
mid-to-low frequency sonars.”
Balcolm and his wife Diane Claridge were in the Bahamas
managing the Bahamas Marine Mammal Survey on the island of Abaco when
the U.S. Navy emitted 16 hours of low-frequency sonar signals within
a 36-hour interval. The whales ran aground within the next 24 hours.
Balcolm and Claridge, strongly critical of the SURTASS-LFA
sonar program since 1999, recognized immediately what they were
seeing. They cut the heads off of two dead whales, stored them in a
restaurant freezer, and flew with the heads to the Woods Hole
Oceanographic Institute on Cape Cod, where the heads were studied by
CAT scan before decomposition destroyed the evidence of sound-induced
internal trauma.
“We got there at 11 p.m. and did scans all night,” Balcolm
told Weiss. “By 3 a.m. the damage was evident.”
Agreed NMFS accoustical research chief Roger Gentry, “There
is no question that tactical mid-range sonars were the sound source
that caused the trauma.”