Thursday, February 26, 2009

Chilly temperatures take toll on manatees

Manatees congregating at FL power plants to keep warm.

An orphaned manatee suffering from cold stress

If you see a sick or injured manatee, call the Florida Fish and Wildlife Conservation Commission hot line at (888) 404-3922.

Cold Weather Killing Twice the Number of Manatees

Twice the usual number of manatees died from the chilling temperatures this winter in Brevard County, and more may succumb as lingering effects of cold snaps take their toll.

"Even if the water temperatures go up, manatee can still suffer cold stress for the next few weeks or even months," said Martine de Wit, associate researcher at the Fish and Wildlife Research Institute in St. Petersburg.

In a year with a record manatee count, cold spells claimed at least 11 manatees in Brevard from Jan. 1 through Sunday and 29 statewide. That compares with a five-year average of 5.6 cold stress deaths in Brevard for the entire year and 28 statewide.

This winter's cold stress deaths in Brevard were the most since 1990, when 28 died from cold.
During cold snaps, sick and emaciated manatees wash up dead with a slew of skin sores and infections that have puzzled marine mammal pathologists for decades.

Cold stress syndrome stems from a succession of physiological changes and diseases triggered by the cold. But why they die in water that only drops to 68 degrees remains a mystery.

Uncertainty over the issue is one of the key reasons state and federal biologists cite for keeping manatees listed as endangered.

Warmth seekers

Natural warm springs over the past century have dried up as humans pulled more groundwater from Florida aquifers.

Now power plants provide much of the warm winter havens, luring manatees farther north than they'd otherwise go during winter months.

On the coldest winter days, more than 600 manatees huddle at Florida Power and Light Co.'s plant in Port St. John and Reliant Energy's plant less than two miles to the north. The plants lie near the northernmost wintering range of most East Coast manatees, federal marine mammal biologists say.

Manatees seeking sparse winter seagrass sometimes venture too far from the warm water areas, exposing themselves to cold water for too long.

Without the north Brevard power plants' discharge, the Indian River Lagoon's temperature could drop into the 50s, weakening manatees' immune systems and subjecting them to disease and death. The discharge warms the nearby lagoon 8 to 13 degrees.

Power plants help

State wildlife officials are trying to come up with a plan for keeping manatees from dying as old power plants convert to newer technology that might not require warm-water discharges.

FPL, for one, vows to keep warming the manatees at its new natural gas plant, expected to be decommissioned in 2010 and built by 2013.

How FPL handles the manatee issue as it takes the Cape Canaveral plant offline next year could set precedent for how other power companies tackle the problem, conservationists say.

While few specifics have been decided, one scenario discussed includes rolling in a "donkey boiler," a diesel generator that would literally boil large vats of water to keep the manatees comfy. That's what FPL did from 2000 to 2002 when it converted its Fort Myers plant to natural gas.

"The decline of warm water habitat is definitely one of the key threats to manatees," de Wit said.
Between Jan. 19 and Jan. 23, state officials counted a record 3,807 manatees in Florida.

Contact Waymer at 242-3663 or

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