As hurricane Milton approaches, Crystal River wildlife researchers and advocates are concerned about how a second hurricane in less than two weeks will further affect manatee habitat.
Manatee biologist Tiare Fridrich said the effects of climate change are intensifying every year, which could create conditions for more storms in the Crystal River area.
Manatees have historically migrated to Crystal River in colder months, but climate change has become one of the primary factors making it difficult for manatees to recover and survive.
Manatees are a threatened species since 2017 when they were removed from the endangered list, according to the U.S. Fish and Wildlife Service. But the increasing number of weather events in the area have some scientists concerned about their recovery.
Vegetation in Kings Bay, Crystal River’s headwaters, was significantly impacted by the past couple of hurricanes, said Fridrich.
“I suspect we will see losses,” Fridrich said about Hurricane Helene and Hurricane Milton, which is expected to make landfall in the Tampa Bay area late Wednesday.
“Scientists have known climate change is the issue for a long time, but I think we’re going to be starting to see worse and more frequent storms,” Fridrich said.
Although Florida-native manatees have adapted to extreme weather events, Fridrich said hurricanes can cause them to go far inland, where they normally would not go, and become trapped when water levels go down.
“Even in areas that are typical manatee habitat... waters that recede to irregularly low levels can also leave manatees stranded,” they said.
“If you have increases in tides, increases in sea level, increased number of storms, storm surges from hurricanes, they drive saltwater up into the freshwater areas,” said Mike Walsh, clinical associate professor of aquatic animal health at the University of Florida. “They affect food source, and then the animals can’t handle that lack of food.”
Walsh said that while there were successful increases in the number of manatees in Crystal River, hurricanes cause saltwater to intrude on the freshwater vegetation. This saltwater can knock back the freshwater vegetation toward the Gulf because it cannot handle the amount of salt there.
A few years ago, an aquatic restoration company replanted seagrass in the Crystal River area which ultimately helped the species, said Walsh. However, this meant that the younger manatees got used to having their food source close by, and most were likely unaware that food was also in the Gulf.
“When the last hurricane threw saltwater up into the Crystal River area, it didn’t kill it all. But it knocked it back enough to where there was less food available for the increased number of manatees,” Walsh said.
He said there could be a delay in how fast a manatee population can react to climate change-related activities, such as needing to search elsewhere for food.
“The climate change changes their behavioral needs and what they’ve adapted to. And they adapt to new things, which then makes it harder for them to go back when something bad happens,” he said.
Pat Rose, 73, is the executive director of Save the Manatee Club, an advocacy group in Florida. He remembers the moment more than 50 years ago when he saw a manatee underwater for the first time in Kings Bay, Crystal River.
He said the first thing he noticed was the manatee’s huge scar -- taking up nearly its whole right side. The manatee was gray-brown with a white scar – a scar he saw in the cloudy water before even seeing the large manatee.
“That, for me, just helped develop my empathy and my commitment to wanting to do something, even then as a teenager,” he said.
Some of the club’s priorities include reducing the causes of manatee mortality and rescuing sick or injured manatees and nursing them back to health before returning them to the wild.
Food sources are threatened by a major saltwater or freshwater intrusion, which is a large amount of water moving into the space, said Rose.
He said as climate change causes sea levels to rise, especially with Crystal River being so close to the coast, plants have less access to sunlight hindering plant sustainability.
“It just shows you how these, you know, vegetative species are impacted by both the ability to have enough light, but also have the proper, you know, solidity for the particular species,” he said.
Seagrass is salt-tolerant vegetation, and Vallisneria, commonly called eelgrass, is a freshwater vegetation. So, either of these receiving an influx of the other water is deadly to the vegetation.
“If over time, you have very slow changes from one to the other, either the salt-tolerant seagrass would make its way upward, or if you have lots of freshwater, the freshwater’s species will, sort of, extend its range downstream, towards the Gulf,” he said.
When these intrusions happen too quickly, Rose said, it eliminates the chance for either of the food sources to survive.
“Once that [sea]grass gets submerged, it doesn’t survive,” said Jim McCarthy, an environmental regulation commissioner and former CEO of North Florida Land Trust.
McCarthy said the lack of vegetation is affecting manatees' ability to survive. McCarthy said sea level rise is a large issue, and he wishes more people would get involved in trying to help.
“I think most people have the tendency to think it’s too big for them to impact,” he said, “And that’s just not the case.”
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