This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:


reputable news agency


Manatee die-off season looms as trial of feeding them lettuce begins again

Credit: Pixabay/CC0 Public Domain

When the state's wildlife department flung the first handful of lettuce to a starving manatee in the Indian River a year ago, it was an act of desperation driven by a catastrophic die-off and violating an environmental golden rule that animal behavior should not be messed with that way.

A Florida Fish and Wildlife Conservation Commission cop might jail an ordinary citizen for such an offense.

The stated goal of providing Florida-grown lettuce to wild manatees was to prevent a repeat of the grim pace of mortalities during the of 2020-21 and to dial back the number of animals that had declined to bleeding, listing, emaciated and organ-failing hulks in need of rescue by private zoos, aquariums and theme parks.

Did the unprecedented provisioning of lettuce for much of last winter at a Florida Power & Light Co. electric plant at the Indian River in Brevard County make any difference?

The state wildlife department's gut answer is most likely. But its biologists say they don't have the science to sort out the intertwined mysteries of manatees' incredible toughness and the Indian River's lethal ecology to quantify a difference.

They do point out that this year will finish with significantly fewer dead manatees in Florida, 783 through Dec. 23, than in 2021, which saw a toll of 1,101, or the most in a year since records began a half-century ago.

But those statistics belie an ongoing massacre.

In 2021, 358 dead manatees were retrieved from Brevard County waters. This year through Dec. 23, after hand feeding the animals with a mass of romaine and other lettuce nearly equivalent in weight to two M1 Abrams battle tanks, 100 tons, just 4% fewer deaths were recorded in Brevard, or 344. No other county is anywhere near that toll.

With this winter already bringing a sting of cold weather, the Florida Fish and Wildlife Conservation Commission and its U.S. Fish and Wildlife Service partner say they have mobilized a more capable lettuce-feeding task force than last year's.

"Going into this year, we still consider this a trial," said Ron Mezich, a state biologist supervising feeding at the FPL plant. "We are adapting daily, finding out new things every day we do this and the goals remain the same—reducing mortalities and rescues."

Winter has become the prime killing season in Brevard's share of the Indian River, a vein of Atlantic along five counties.

Seagrass beds have been eradicated because of a legacy of pollution, leaving the grazers, sometimes called sea cows, with too little to eat.

Weakened by starvation, they are finished off by water temperatures in the 60s and below, which is why they gather by the hundreds in the warm waters of the FPL plant.

State biologists cautiously suspect that the death toll has reached a turning point and may ease this winter.

Last year in December, the state counted 22 deaths in Brevard County waters. Through the 23rd this December, there have been two mortalities.

Some of that optimism is from varied and limited observations recently that manatees in Brevard are not as stricken as they were last year perhaps because they had better success in foraging during warmer months.

Pat Rose, executive director of Save the Manatee Club, said that could be wishful thinking based on thin evidence. Another explanation may be that only the more robust manatees have lasted this long.

"The most vulnerable manatees likely and unfortunately suffered and died first because of the dire situation that had been allowed to fester over so many years," Rose said.

So far, dozens of manatees have been examined or observed, but the conditions of nearly 1,000 others remain unknown, Rose said.

January likely will be a real measure of the perils that manatees face in Brevard County.

In 2021, Florida's deadliest recorded year for manatees, the January toll in the county was 73.

This year in January, the number of dead rose to 82. More than half, 45, were recovered from Indian River waters adjoining the Florida Power & Light Co. plant.

Carcasses were towed in sporadically during the first three weeks of the month. As winter deepened, they arrived in waves: 5 on the 21st, 5 on the 27th, 11 on the 28th, 5 on the 29th and 5 on the 31st. They were taken ashore at a public boat ramp just a football field away from the power plant.

"I will easily go out on a limb and say it would have been much worse had they not done the feeding last winter," Rose said.

February last winter was far and away the deadliest in Brevard with a toll of 177.

With January and February looming again, Rose said he is encouraging the state and federal wildlife agencies at the FPL plant to provide more lettuce to manatees, if, as during last winter, they eat every scrap down to quarter-inch flecks.

"We want to see enough provided that the manatees are showing that they are willing to leave some behind," Rose said. "If they are completely consuming everything you are feeding them, then they want more and there is a need for more."

He also would like to see the regular use of water heaters installed at the feeding site as backups for occasional periods when the power plant is down and not discharging warm water.

The feeding site is nearly a mile from where warm waters are discharged, with the two locations separated by a long jetty.

Last January, when the plant and its warm-water discharge temporarily were shut off and the heaters at the feeding site were turned on, manatees responded, Rose said.

"It literally wasn't until the heaters went on on the 19th of January, and I was out there, and right after they went on, more manatees began showing up, and they kept increasing because they were more than happy to eat in that warmer ."

So far, he said, manatees have to make the "terrible choice" of staying warm or finding food at the plant site.

2023 Orlando Sentinel. Distributed by Tribune Content Agency, LLC.

Citation: Manatee die-off season looms as trial of feeding them lettuce begins again (2023, January 3) retrieved 22 May 2024 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further

Manatees' starvation may be easing in Florida, authorities say


Feedback to editors