Winter could be even more deadly for manatee population, wildlife experts say

Many sea cows dying of starvation

Manatees have been dying at alarming rates since the beginning of 2021. (WKMG)

Wildlife biologists fear another cold, harsh winter in store for Florida’s starved sea cows, according to News 6 partner Florida Today.

They worry when Florida waters chill and seagrass recedes in a few months, manatees again will die by the hundreds on the heels of a year in which 890 sea cows already have perished, mostly from starvation.

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So they’re scrambling to figure out how to spend $8 million in state manatee recovery money and to streamline permits that rehab facilities such as SeaWorld are required to get to save more sea cows.

“We’re working to expand the facilities and we’re doing that in case we have more mortalities this winter,” said Larry Williams, a manatee biologist with the U.S. Fish and Wildlife Service. “There are a very high number of abandoned calves. So preparing for next winter, we’re working with groups to expand and make sure they have the permits.”

Manatees are crashing in 2021 like never before. Already, the deaths broke the 2013 record of 830, and have more than doubled the five-year average of 396 deaths, according to the Florida Fish and Wildlife Conservation Commission. And while the rate of deaths seems to have decreased in recent weeks, winter’s yet to come, with countless emaciated, weakened survivors and orphans at large.

Stress from cold waters killed an average of 42 manatees (11% of overall deaths) over the past five years. of manatee deaths. But harsh winters can kill many more.

FWC met in Bonita Springs Wednesday to talk about the federally declared Unusual Mortality Event that has claimed 316 sea cows in Brevard’s stretch of the Indian River Lagoon, or 36% of the overall deaths this year. The death toll got so bad that in April, the National Oceanic and Atmospheric Administration declared the die-off an Unusual Mortality Event, which frees up federal funding and other resources for the response.

Still, biologists don’t know much more than that manatees are starving from seagrass loss that happened over decades, caused by polluted runoff, fertilizers, leaky septic tanks and sewage spills, especially in the lagoon.

“What hampers that investigation is the hot summer,” Martine deWit, the FWC veterinarian who runs the agency’s necropsy lab in St. Petersburg, said late last month. “They decompose so quickly, so we’re not even transporting across the state right now.” (A necropsy is an examination on a dead animal).

Adding to the trouble, in mid July FWC’s cold room that holds manatee carcasses and remains at the St. Petersburg lab broke down, complicating logistics of examinations. The costly new condenser they need won’t be ready until the end of this month.

“So we currently necropsy on the fly, with use of dumpsters and landfill, and added complicated logistics,” deWit said via email.

While manatees seem to be doing better recently, deWit said the long-term impacts of malnutrition could cause future reproductive and other health problems, especially this winter. “Obviously, we can expect some sub-lethal effects,” deWit said.

Gil McRae, director of FWC’s staff, told commissioners the problem goes beyond the recent die-off.

“Ultimately it is not a manatee problem,” McRae said. “It’s more complicated than that. And we want to make sure commissioners understand the sense of urgency.”

The Legislature this year approved $8 million to restore manatee access to springs and improve habitat in other manatee hotspots. The agency has 18 months to designate how to spend the money and five years to complete the projects. FWC staff are in the process of identifying and prioritizing those restoration projects.

FWC plans to finish seven eelgrass restoration projects within the lagoon’s tributaries this year. Staff also is conducting aquatic vegetation restoration near springs in the St. Johns River and a restoration project at Blue Spring State Park.

With the population nearing 8,900, some at Wednesday’s meeting said the overall manatee story should be positive and should focus on how well the animal has recovered in the past three decades. Yearly winter counts that 20 years ago typically found just a few thousand manatees in recent years topped 6,000 sea cows.

Boating advocates in the lagoon region have long argued that the species’ population has outstripped the capacity estuaries like the lagoon to support such large numbers long term. Runoff and sewage pollution spur excess algae that chokes out seagrass, which has done way more to harm manatees than their boats, they say.

McRae said death rates have returned to more normal levels on the east coast, pointing out that the state has experienced a year’s worth of manatee deaths in six months.

“We had manatee deaths along the entire Atlantic coast from lower St. Johns to southeast Florida,” McRae said. “By May of 2021 the number of carcasses had returned to normal levels. But because of this big slug of manatees on the east coast, we’ve already set a record six months into the year.”

McRae said the agency is trying to deal with a large number of calves that are often in poor health after losing their mothers.

“One thing that’s unique to this particular event that we haven’t seen before is a number of motherless calves,” McRae said. “These calves require a great deal of care and they often have to be bottle fed and it can be two years until they’re ready to be released from captivity.”