From ANIMAL PEOPLE, April 1996:
Theories are many but proof lacking
concerning the causes of recent multiple
mysterious mass deaths of marine mammals
in different parts of the Atlantic. First, from
mid-January to February 22, five or six
northern right whales––the count was disputed––were
found dead in their wintering and
calving area off Georgia and Florida. On
March 11 yet another right whale washed up
at Wellfleet, Massachusetts. The current
northern right whale population is believed to
be no more than 300, and the deaths equal
the total known number of calves from 1995.
Fourteen calves are known to have been born
this year, but three were among the dead.
On March 13, International
Wildlife Coalition staff scientist David Wiley
and Humane Society of the U.S. marine
mammal advocate Sharon Young argued in a
joint statement that, “The deaths coincide in
time and space with naval maneuvers that
involve gunnery practice and bombs.” One
whale was clearly rammed by a ship.
Concussion from explosions, according to
Wiley and Young, could account for several
of the other deaths.
Biologist Jose Manuel Azevedo of
the University of the Azores reported 21 dead
cetaceans of eight species washing up in the
Azores between February 7 and March 10,
where usually no more than one or two wash
up per year. The only evident explanation
was a run of unusually cold weather.
Finally, at least 61 manatees died
during February and early March near Fort
Myers, Florida, including 33 within 10
days, March 5 through March 15, rapidly
depleting a record statewide count of 2,639,
posted just before the first deaths were noted.
All were well-fed; all had a form of bacterial
pneumonia, but investigators were inclined
to believe the infection was a symptom rather
than a cause of the underlying problem.