Washington, DC — This past year has been calamitous for Florida’s manatees, with the second highest mortality ever recorded, according to preliminary figures posted today by Public Employees for Environmental Responsibility (PEER). All told, more than 800 manatees died in 2018, a nearly 50% increase over the prior year, as Florida’s total manatee population starts to shrink.
Florida Fish & Wildlife Conservation Commission (FWC) tallies through December 21st show –
- A total of 804 manatee deaths, higher than any other year save the massive die-off in 2013 which saw 830 deaths;
- More than a quarter (209) were red-tide related, more than triple the toll taken in 2017 and again second only to the 277 red-tide deaths in 2013; and
- Compounding these losses was a record number of deaths from boating collisions, with 119 tallied so far this year, compared to 111 in 207 and 102 in 2016, both previous record totals.
“Nothing is going well for Florida’s manatees this year,” stated PEER Executive Director Jeff Ruch, noting that these totals could go much higher when year-end figures are finalized. “From pollution induced red-tides to speedboat propellers, humans are responsible for most manatee deaths.”
These losses appear to be reflected in a decreasing population. More than 13% of the estimated 6,131 manatees counted in January have already perished. That population estimate comes from FWC’s winter aerial surveys covering all manatees wintering habitats in Florida (called synoptic surveys). Those overall population estimates fell by nearly 500 since the beginning of 2017.
There is a growing question as to whether these losses threaten a sustainable population. The potential biological removal level (PBR) is defined by the Marine Mammal Protection Act as the maximum number of animals, not including natural mortalities, that may be removed from a marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population. In contrast to the hundreds of manatees lost each year due to human-related causes, the PBR for manatees is approximately 12 per year.
“How many more bad years can manatees endure before triggering an irreversible downward population spiral?” Ruch asked, pointing to mounting efforts to restore the manatee’s endangered status under federal law after it was downgraded in 2017. “In coming months, extreme weather, especially cold snaps, and loss of warm-water habitat will further imperil the Florida manatees’ already tenuous future.”
Cold weather also added to 2018’s manatee losses, with 72 cold stress deaths, more than triple those in each of the prior four years. Back in 2010, a disastrously severe cold spell caused 282 manatees to perish.
###
Compare 2008-2018 manatee mortality, including red tide-related deaths
View FWC synoptic survey results