The year that just ended was a deadly one for manatees in Florida.
Preliminary data shows that 538 manatees were found dead in Florida waterways last year, according to state officials.
This is the third-highest annual death toll on record for the large sea cows, with 71 deaths reported in Pinellas, Hillsborough and Manatee counties.
Collisions with watercraft and red tide-related fatalities were among the major contributors to last year’s high mortality rate. The Florida Fish and Wildlife Conservation Commission (FWC) says there were 106 watercraft-related deaths and 63 Red Tide-related deaths during 2017.
Red tide comes from a toxic algae bloom that starts offshore and drifts inshore through currents and winds. The algae produce toxins that can kill fish and deplete oxygen in the waters. During the spring of 2017, southwest Florida experienced a persistent red tide bloom, which state officials say may account for the high number of manatee deaths in those areas.
Michelle Kerr, a public information specialist with the commission, says one out of every nine deaths last year were caused by the poisonous algae bloom.
“Manatees ingest red tide through food – the toxins can be built up on sea grass,” said Kerr. “They can also inhale it through the air and water intake. These toxins then paralyze the manatees, causing them to drown."
The highest annual death toll for the large marine mammals occurred in 2013, with 830 manatees reported dead as a result of weather changes and a red tide bloom, as well as a still-unknown malady in the Indian River Lagoon that led to 111 manatee deaths. The record is followed closely by 2010, when 766 manatees were reported dead.
The U.S. Fish and Wildlife Service downlisted manatees from endangered to threatened in early 2017 after officials saw an increase in manatee populations and an improvement in its habitat. However, if deaths continue to rise, they may be placed back on the endangered species list.
To report a dead or distressed manatee, call the FWC’s Wildlife Alert Hotline, at 888-404-3922 (FWCC). Florida residents can also purchase a specialty ‘Save the Manatee’ license plate or decal at their local tax collector’s office; proceeds go directly towards manatee research and conservation efforts.