Subject: Info: Diagnosis of Fatal Manatee Dis (fwd)

Michael Williamson (
Thu, 2 May 1996 18:30:20 -0400 (EDT)

---------- Forwarded message ----------
Date: Thu, 2 May 96 02:52:00 UTC 0000
Subject: Diagnosis of Fatal Manatee Dis

Diagnosis of Fatal Manatee Disorder Continues to ...
COMTEX Newswire
   ATLANTA, May 1 /U.S. Newswire/ -- The cause of the killer disease that since
March 1996 has claimed the lives of more than 150 of Florida's endangered
manatees has so far eluded a special national team of experts of wildlife
biologists and other marine mammal experts.
   In search of a diagnosis, many collaborators from federal, state and private
organizations have been assisting Florida Marine Research Institute scientists
with the ongoing investigation by testing the hypotheses most likely to
explain the record-breaking number of manatee deaths over the past 6 weeks.
   Since January 1, 1996, more than 255 manatees have been found dead in
Florida's waters.  Some 155 of these deaths, however, have inexplicably
occurred in Southwest Florida since March 5, 1996, and recent analyses of
blood and tissues are providing clues, but have so far failed to determine
conclusively the actual cause of death. The February 1996 U.S. manatee
population count turned up at least 2,639.  This shows that approximately 9.6
percent of U.S. manatees have perished in the first 4 months of this year, a
significant loss.
   Experts are testing three different hypotheses in their search for a cause
death: 1) death caused by a biological toxin, such as that produced by a red
tide; 2) death resulting from a disease caused by a virus or bacterium; and 3)
death caused by a contaminant, such as a pesticide.  It is also possible that
a combination of factors is involved.  Tissue samples collected from dead
manatees have been sent to laboratories across the country with expertise in
identifying biotoxins, infectious agents, and contaminants.  None of the
results received so far have been conclusive.
   The Florida manatee -- whose gentleness and approachability has endeared it
millions of Floridians and visitors to the State -- is a large herbivorous
marine mammal that was listed as an endangered species in 1967.  Its recent
high death rate was the main topic of discussion at an April 19, 1996, meeting
held at the Florida Marine Research Institute in St. Petersburg, Fla.
Biologists from the Florida Department of Environmental Protection, the U.S.
Fish and Wildlife Service, the National Biological Service, the University of
Miami, Mote Marine Laboratory, and Sea World of Florida presented findings and
discussed strategies to coordinate and enhance their fact-finding mission and
to determine the cause of these fatalities.
   The Florida Marine Research Institute has organized an effective team
to document this highly unusual manatee loss of life. Information has been
collected on dates and locations of dead manatees, and environmental data has
been gathered, including water temperature, salinity, and counts of the
phytoplankton (toxic microscopic marine organisms) that cause red tide blooms,
patches of red discoloration in the water caused by trillions of these tiny
organisms.  This information has been entered into a geographic information
database so that clues to the manatee deaths can be identified and analyzed.
A preliminary review of existing data has shown that there is a striking
correlation between the distribution of dead manatees and sites with high
phytoplankton counts; however, a definitive causal relationship between the
red tide and the manatee deaths has yet to be firmly established.
   A review of the Florida Marine Research Institute's red tide data for the
20 years indicates that in only two years, 1982 and 1996, have the
phytoplankton levels been high and persisted into March and April. A favorite
spot for Southwest Florida manatees to spend the cold winter months is in the
vicinity of the Florida Power and Light plant on the Caloosahatchee River near
Fort Myers.  In February 1996, more than 400 manatees were sighted
congregating at this location.  Typically, as the weather begins to warm in
late February and early March, these manatees start to make their way back
towards the Gulf of Mexico.  During the first weeks of the recent die-off,
this river proved to be a key area for fatalities. In 1982, however, only 37
manatee deaths were attributed to ingestion of the red tide phytoplankton,
which they encountered as they migrated downriver towards the ocean.
   Some live manatees, exhibiting apparent neuromuscular problems have been
rescued in Southwest Florida and taken to a rehabilitation facility at Lowry
Park Zoo in Tampa.  The recovery of three females took several days, during
which they required assistance to stay afloat to breathe. Caretakers used
flotation vests to help keep the disabled manatees from drowning.  A male
manatee was recently rescued by state biologists and is expected to recover.
   The U.S. Fish and Wildlife Service and the National Biological Service will
continue to assist Florida Marine Research Institute researchers in its
efforts to document and understand this tragic manatee die-off, and will
identify research and management needs to prevent or reduce such events in the