Carcasses of babies are up dramatically; explanation a mystery
David Fleshler, South Florida Sun-Sentinel 18 Jan 09;
A record number of baby manatees were found dead last year, despite strenuous public and private efforts to restore a species that ranks with the panther and alligator as a symbol of wild Florida.
State wildlife officers recovered 101 infant manatee carcasses in 2008, up from 59 the previous year. The young manatees died from a variety of natural causes — although decomposition was too far advanced to tell what killed many of them — and no one knows the reason for the sudden increase or whether it indicates any new threat to the species.
The Florida Fish and Wildlife Conservation Commission, which tracks manatee deaths, says the high number may simply be a result of more manatee births or more success in finding carcasses. But The Save the Manatee Club said it could be an indirect result of boat strikes, habitat loss and other threats that have shortened the endangered mammals' life spans, reducing the number of experienced mothers bearing calves.
In Palm Beach County, no dead babies turned up last year, although collisions with boats took a toll on adults. In Broward County Click here for restaurant inspection reports, authorities found three and are concerned about the fate of a fourth.
Last month, a female manatee with a calf was spotted in Hollywood, suffering from severe injuries from a boat collision. Wildlife officials have tried to rescue them, without success, said Pat Quinn, the county's manatee protection supervisor. If the calf is still nursing, he said it likely will die if the mother dies.
Statewide, the calves' causes of death varied: 26 were stillborn, eight orphaned or abandoned, five died from cold and the rest from various natural or undetermined causes, said Martine DeWitt, a scientist with the wildlife commission. The significance of the increase is unclear, she said.
"It's possible that a relatively high percentage of calves died," she said. "But it's always possible that more calves had been born, which is a good thing."
Katie Tripp, director of science and conservation for The Save the Manatee Club, said the state should consider whether the increase represents an emerging threat. In the difficult environment of America's fourth-largest state, she said manatees rarely reach their full 60-year life span. This means there are fewer experienced mothers.
"We know manatees are dying young," she said. "We know first-time mothers tend to be less successful."
No one knows how many manatees live in Florida, but aerial surveys generally count about 3,000.
Enormous resources have been devoted to protecting them, as scientists research red tide, police patrol for speeding boats and government agencies protect coastal habitats. Tripp said the 30-year protection effort preserves many of the environmental assets that originally drew people to Florida.
"When you protect manatees, you protect seagrass flats," she said. "When you protect manatees, you protect water quality. When you protect manatees, you protect springs. When you protect manatees, you protect all of coastal Florida."
The number of manatees killed by watercraft is a closely watched figure, invoked in debates over boating, environmental regulation and the impact of waterfront development. Last year watercraft killed 90, up from 73 the previous year but short of the record of 95 in 2002. In Broward County, they killed three, which is about average. But Palm Beach County saw six, a tie for the record.
Paul Davis, Palm Beach County's manatee coordinator, said he was surprised by the increase since the recession cut boat traffic, police increased water patrols and no manatees were killed by boats in the previous two years. He urged boaters to slow down, particularly in three manatee hot spots: the Loxahatchee-Jupiter Inlet, the Lake Worth Lagoon and Lake Wyman, in Boca Raton.
"We need to be concerned," he said. "We need to continue to monitor our enforcement and education efforts and hope it doesn't repeat the following year. If it does, then we're going to reevaluate what we're doing and see if we can do it better."
