MIAMI -- The homely manatee may be among the best-loved animals in Florida -- its picture is on a fund-raising license plate -- but it is a creature shadowed by extinction.
So far this year, 47 manatees have been found dead in Florida -- double the rate at this time last year, when a total of 192 perished. An aerial survey last month spotted 1,443 of the animals -- down from a high of 1,856 three years ago.
Scientists are alarmed.
"Unlike the extreme cold temperatures in 1990 -- the highest single year for manatee mortality, with 206 deaths -- no single large natural event occurred in 1994 to which we can attribute the high mortality," said Pat Rose of the Florida Department of Environmental Protection.
More than 20 years after they were listed as endangered and given federal protection, the manatee's fate still rests in the balance between preserving natural ecosystems and meeting people's wants.
Most manatee deaths result from collisions with boats and propellers, getting crushed in flood-control gates and from unknown causes that produce a high infant mortality rate.
A spate of adult female deaths has left a record number of manatee orphans unable to fend for themselves. Seven were being cared for at the Miami Seaquarium, where veterinarian Greg Bossart lamented, "We're killing off the species."
"The good news is that 11 Florida coastal counties have protected thousands of miles of waterways with go-slow zones," said Judith Vallee, executive director of the 38,000-member Save the Manatee Club. "The bad news, however, is that manatees are still dying because the waterways are unsafe, and the state has relied on voluntary compliance with the speed laws."
Manatees also are threatened by pollution and turbidity that impedes growth of plants on which they feed.