WEEKI WACHEE GARDENS, Fla. — A manatee biologist is using her expertise to hypothesize what may be behind a rash of recent manatee deaths in Hernando County.
As we’ve reported, six manatees have been found dead in the Mud River, which is located near Weeki Wachee Gardens.
Tuesday, the Florida Fish and Wildlife Conservation Commission (FWC), which is officially investigating the deaths, released some of its preliminary findings.
“Investigations attribute these deaths to an acute lethal gut shock from a sudden dietary change,” the FWC wrote, in part.
Tiare Fridrich with the Save the Manatee Club believes the "dietary change" is happening because of an environmental change caused by Hurricane Idalia.
“One of my first thoughts was, well, there is less available eel and sea grass in the area due to the hurricane that came through,” she said. “With that storm coming through, a lot of the grasses died.”
According to Fridrich, Idalia’s surge may have temporarily changed the salinity and turbidity in the Mud River, which contributed to the die-off of grass. Manatees in the area may have eaten less nutritious algae as a result. Doing so can alter a manatee’s gut biome.
“Imagine you go on vacation, and you eat a bunch of new food you’re not used to. Your body’s going to be shocked by it,” she said.
Fridrich added that manatees are already under more stress than usual during cooler winter months. They may have isolated themselves in the Mud River because they were already in a “compromised state.”
However, she said manatee research in Hernando County is largely lacking when compared to other areas of the state.
“It’s possible that the Mud River is more important to manatees in that area than we ever thought,” she said.
Though she said the grasses manatees eat traditionally respawn in the springtime, external man-made stressors — like excessive nutrient pollution and shoreline erosion — have made the natural regeneration less of a sure bet.
“Our aquatic habitats in Florida are not able to rebound the way they did historically because they are not healthy,” Fridrich said.
Fridrich ultimately believes the rash of deaths illustrates why greater manatee protections are needed in Hernando County, where boat strikes have also been documented in past years.
“We do know that they do get hit by boats and have been killed by boat strikes in the area, so on top of now having less access to food, it’s another threat that they’re facing in this area — and there is very limited protections for manatees there,” she said. “We need to do more to make sure we’re protecting our marine environment.”
In a Tuesday meeting of the Hernando County Board of County Commissioners, commissioners largely agreed.
Some floated the idea of reducing boat speeds along the entire length of the Mud River to protect manatees and the grasses they eat.
However, commissioners said local rule has been diminished, and they aren’t sure what actions they can take without the state’s cooperation.
