Manatees dying at an alarming rate in Florida
NBC News — Florida’s manatees are dying at unusually high rates this year, and experts said the sustained loss of a key food source is to blame.
The Florida Fish and Wildlife Conservation Commission’s most recent report, which spans Jan. 1 to May 28, recorded 761 manatee deaths in 2021. Researchers are concerned that the current death rate could surpass the record 804 manatee deaths recorded in 2018.
“If this continues through the rest of the year, this is going to be one of the highest mortality years ever,” said Jon Moore, a marine biologist and oceanographer at Florida Atlantic University in Boca Raton.
Moore said the main issue is worsening water quality in Florida’s waterways from wastewater contamination and nutrient runoff that trigger toxic red tides and overgrowths of algae, known as algal blooms. These recurrent problems are killing off seagrass, seaweed-like plants that grow underwater and are a main food source for manatees.
Algal blooms happen when microscopic organisms grow at a fast rate and generate dangerously high levels of toxins in the water. These blooms can occur naturally, but nutrient pollution from toxic wastewater, fertilizers, stormwater runoff and other contamination sources can intensify outbreaks of algal blooms — and make them more frequent.
“The algal blooms are clouding the water and cutting off light, so the seagrass can’t photosynthesize and sustain themselves,” Moore said, adding that manatees face starvation and malnourishment as a result.
Decades of nutrient pollution are compounding the environmental stresses on Florida’s fragile ecosystems, said Patrick Rose, executive director of Save the Manatee Club, a nonprofit that was established in 1981 by singer Jimmy Buffett and former Florida Gov. Bob Graham.
“River systems and lagoons can absorb these nutrients to a degree, but once you pass a tipping point, we start to get these massive algal blooms,” Rose said. “This shows that we need to completely re-examine how we grow and develop sustainably.”
Manatees were considered “endangered” by the U.S. Fish and Wildlife Service, but a politically contentious decision in 2017 changed the animals’ conservation status to “threatened.”
“This year’s mortality event may require greater protection for manatees, and we might need to bump them back up into endangered status,” Moore said.
Scientists are also concerned about potential ripple effects throughout Florida’s ecosystems. Algal blooms don’t just affect manatees: They can also impact crucial fisheries and other marine habitats.
“Rays feed on seagrass, as well as turtles,” Rose said. “This will also affect different species of fish, and the fish that feed on those fish. It’s something that will affect the entire food chain. When these systems collapse, it gets pretty ugly.”