The Florida manatee is a conservation success story, with as few as 1,000 remaining in the wild just a few decades ago. Unfortunately, this docile, lovable marine mammal faces new threats.
Learn more about the Florida manatee, and what we can do to conserve this species along with its fragile habitats.
Crystal River Eelgrass Restoration
Thanks to direct access to the Gulf of Mexico and the presence of several artesian springs, Crystal River and King’s Bay have been critical habitats for manatees for thousands of years. In recent history, however, human impacts (nutrient runoff and physical stressors) have resulted in the collapse of important eelgrass meadows and the invasion of nuisance algae, especially lyngbya.
Concerned citizens and conservationists banded together to form the grassroots organization Save Crystal River, and launched a restoration project in 2011 to bring back the traditional, lush beds of eelgrass. They began by sucking off tons of lyngbya and muck from the bay using, basically, giant underwater vacuum cleaners.
Next, two species of eelgrass were selected, cultivated and replanted throughout King’s Bay. In order to allow those out planted areas to take root and spread, temporary, underwater cages were installed to prevent manatees from eating up the new grass.
Today, the transformation of King’s Bay is remarkable. Acres of healthy eelgrass continue to spread, water clarity has improved dramatically, and now the resident manatees have plenty of food to eat.
The Florida Manatee
“So everyone comes here to Crystal River to swim with these manatees, they’re such a fun, lovable, peaceful, docile creature. They’re so ugly, that you gotta love them. Them big, huge snouts and the whiskers, um, they’re absolutely adorable.”
How can you argue with that. Crystal River, on Florida’s west coast, is often called the manatee capital of the world, and people from all over come to visit these docile marine creatures. This is, in fact, the only place where it is legal to swim with manatees in the wild.
Most guides, like Don, make sure their guests practice passive observation. Pursuing, touching and surrounding manatees can disturb their behavior. We don’t want to chase them away from their habitats or get slapped with a hefty fine. If you go to Crystal River to see manatees, keep that in mind.
So what, exactly is a manatee? Until recently, this docile mammal was mythologized and misunderstood.
Sirenians, often called “sea cows,” are aquatic mammals distantly related to elephants.
There are two sub-species of the West Indian manatee: The Florida manatee and the more widely distributed Antillean manatee.
How about some Florida manatee facts:
This species can grow to over 9 feet long and tip the scales at more than 1,000 pounds.
Manatees have some interesting adaptations for a life aquatic. Densely mineralized rib bones act as ballast, or weights, allowing the animals to sink to the bottom while resting or feeding. Also, they have elongated lungs and specially designed diaphragms. Think of these features as buoyancy control devices, like what scuba divers wear. Super handy for a marine mammal.
The only strong social bond is between the mother and her baby. If you listen closely, sometimes you can hear the calf’s chirping vocalizations. So cute.
Mothers typically only give birth to a single calf and on very rare occasions, twins.
“Manatee calves are dependent on their mothers for 2 years. And in that time they learn everything from their mothers: where to find food, where to find warm water, those migration routes, they nurse from them in that time, and it’s critical for manatees to have that exposure to be able to go out after they reach a sub adult age and be productive animals.”
Calves nurse from nipples located near the mother’s armpits. Weird, but hey… it seems to work for them.
Manatees are herbivores. They can consume as much as 10% of their body weight in veggies each day, grazing and browsing for up to 8 hours. They are primarily found in the warm, coastal waters of Florida, and seagrass is their favorite food. They’re teeth wear down quickly since they spend so much time munching. Fortunately, they have what are called “marching molars” which constantly replace themselves over time. This is a feature shared with their distant relatives, the elephants.
Many of the waters they navigate can be quite turbid. Their beady little eyes aren’t very perceptive, but nerve endings on the follicles of the wiry hairs distributed all over their bodies allow them to feel their way around quite effectively.
Manatees have no natural predators, emphasis on “natural.” But they face many threats.
“So manatees were probably always hunted by the original peoples, in fact they have found evidence of manatee bones in middens and things like that, and then Europeans came and they were also hunting manatees. There were advertisements in New York, for example. “Come to Florida to hunt manatees.
But then that hunting pressure was replaced by manatees being killed and harmed by watercraft.”
Boat strikes are such a constant threat, in fact, that most manatees in Florida bear the scars. But it’s not the nasty gashes that are often fatal. It’s the impact. Their bones are hard, but brittle. Broken backs and ribs are the real killers.
And then there’s habitat loss due to human development and pollution.
“ Manatees have no natural predators, but they rely on healthy seagrass meadows and shoreline vegetation for their nutritional needs.”
But these food sources are disappearing.
Manatees are a tropical species and are very sensitive to cold weather. Although they look chunky, they’re surprisingly lean. They do not have a substantial, insulating layer of blubber like whales and seals, and cannot survive sustained temperatures below 68 degrees Fahrenheit. During the winter months, Florida’s ocean waters often dip into this dangerous territory. When this happens, manatees look for warmth, and they can find their temperate, crystalline refuges in Florida’s springs, where the water is a constant 72 degrees regardless of the season.
Manatees conserve their energy during cold weather events: eating less, resting a lot. They’re simply trying to survive. While you may find a few in the springs during the summer, most are spread out along their coastal feeding grounds. But here in February, Blue Springs is the place to be for over 600 manatees. Can you blame them? The water is balmy, pure, and the setting is gorgeous.
The Florida manatee is a conservation success story and as few as 1,000 individuals could be found in Florida just a few decades ago. Today their numbers have grown enough to upgrade their conservation status from “endangered” to “threatened.” Still, they face an uphill battle.
“ So manatees are a pretty rare animal. We have about 6,000 of them here in Florida, and last year alone, unfortunately, we lost over 1,100 manatees, which is a really high number. If you’re thinking about 6,000 at first that may sound like a lot, but manatees don’t reproduce very quickly. They usually have one calf at a time, take care of their calf for about 2 years, so it’s a very very slow reproduction rate.”
Imagine that. As much as 20 percent of the total population of Florida manatees perished in a single year. Referred to as an “Unusual Mortality Event,” or UME for short, most of these deaths were attributed to starvation in coastal habitats where seagrass, their main food source, has been disappearing.
“ So as a human species we usually love what we know and protect what we love. So the more we learn about a creature such as the manatee, the more we care about it and the more we want to protect it.
The thing is, a lot of what’s happening to manatees right now is human related. So I think, because it’s human caused, it’s also our task, as humans, to do something about it and fix it.”
I couldn’t agree more. And in the case of the Florida manatee, as well as countless other marine creatures, saving the animals means preserving their habitats: The crystal-clear springs and lush coastal estuaries which make Florida such a beautiful place to live and explore.
