Report: As many as 11,730 manatees remain in Florida, despite famine from seagrass loss

Jim Waymer, Florida Today
Updated ·4 min read

Sea cows seem to be fending off famine, at least as an overall population.

Despite recent years of starvation, there were as many as 11,730 manatees in Florida last year, only one year after a record 1,100 sea cows died, according to a new report.

But researchers warn that the data is too uncertain to read population trends.

What report?

The report is entitled, "2021–2022 Statewide Abundance Estimates for the Florida Manatee," written by the Florida Fish and Wildlife Conservation Commission and the U.S. Geological Survey. It updates a 2018 report, based on the newly available data.

What did they find?

They estimate there were 9,790 manatees in Florida in 2021 to 2022, but the population could range from as low as 8,350 to as high as 11,730 manatees, of which 4,630 (3,960–5,420) were on the west coast of Florida and 5,160 (3,940–6,980) were on the east coast.

How does that compare to previous estimates?

Similar efforts estimated 8,810 manatees (7,520–10,280) in 2015–2016 and 6,810 (5,680–8,110) in 2011–2012.

Is this good news or bad?

Depends on who you ask. Boating advocates who have challenged slow-speed manatee zones for years say it's great news and shows that the only reason so many manatees are dying is because there numbers have increased so much. They say the much bigger risk than their boats is the warm-water discharge from power plants that lures too many manatees too far north in the winter, killing them from the stress of the cold.

FWC, USGS and nonprofits that advocate for manatees have warned for years against reading too much into population estimates from any one year, given the remaining threats to manatees from pollution, seagrass loss and boats.

Manatee debate pits activists against boaters

In February 2023, state and federal wildlife officials invited media to document manatee feeding at the Florida Power & Light’s Cape Canaveral Energy Center on US 1 in Cocoa. For the past two winters, officials have fed manatees there to keep them from starving. A recent report shows manatees numbers stayed stable last year, despite many that starved because of seagrass loss.

Can these surveys be used to plot population trends?

The researchers recommend against inferring population trends by comparing the estimates of these surveys. Instead, they say these estimates are just one of multiple sources of information that can be used to infer trends.

Why is it important?

Knowing the manatee's population size is vital for protecting the species and managing its habitat.

What is the manatee's federal listing status?

They were "downlisted" to threatened in 2017 but nonprofits are pushing the U.S. Fish and Wildlife Service to restore the species status to "endangered."

What legal actions are going on to protect manatees?

In May 2022, three conservation groups filed a second federal lawsuit blaming poor water quality in Florida for “catastrophic mortality” of manatees. The Center for Biological Diversity, Defenders of Wildlife and the Save the Manatee Club filed the suit in federal court in Orlando.

The groups want to require the U.S. Environmental Protection Agency to re-engage in talks with the USFWS and the National Marine Fisheries Service about water quality in the Indian River Lagoon, where most manatees live and die.

In February 2022, the same groups filed a separate lawsuit in federal district court in Washington, D.C., contending the USFWS violated federal law and failed to take final action on a 2008 petition to revise “critical habitat” designation for manatees.

In November 20222, an environmental nonprofit called Bear Warriors United Inc. also filed suit in the Middle District of Florida in Orlando against the Florida Department of Environmental Protection, accusing the agency of failing to protect manatees under the Endangered Species Act.

How many manatees have died this year?

According to the latest FWC figures, at least 502 manatees had died this year through Nov. 17, including 46 in Brevard. The most, 107, were found dead in Lee County.

By comparison, there were 745 manatee deaths statewide by the same date last year and a record 1,012 in 2021. The 5-year average for that same period of time is 695 manatee deaths.

What killed them this year?

Of the 502 that have died this year statewide, the causes were as follows:

  • 84 by watercraft;

  • 7 by a flood gate or a lock;

  • 83 died within a year of birth;

  • 11 from cold stress;

  • 80 of natural causes;

  • 186 had no examination to determine cause;

  • 38 of undetermined causes;

  • 13 of other human causes.

Brevard tops the state with more than half the manatee deaths in 2022

Where can I read the FWC/USGS manatee report?

It's posted here: https://f50006a.eos-intl.net/ELIBSQL12_F50006A_Documents/Final_1.5_TR27_231027.pdf

This article originally appeared on Florida Today: Report: As many as 11,730 manatees remain in Florida, despite famine