Researchers unsure why Florida manatees are appearing in Mexico and Cuba

Several sightings of a manatee and her calf in a power plant intake canal near the Cuban town of Santa Cruz del Norte, about 33 miles (54 kilometers) east of Havana, occurred throughout the winter and spring of 2007.

Manatees aren’t known to frequent the canals of Cuban power plants. This type of behavior is more common in Florida, where the creatures are forced to seek out warm industrial rivers due to the cooler temperatures.

The information was shared with the USGS Manatee Individual Photo-identification System, which has been collecting and registering images of manatees around the country for over 40 years, typically through unique body scars left by passing boats. There are currently around 3,000 manatees in the system’s database.

This particular manatee had several scars over its left flipper and across its tail, allowing researchers to confirm it was the same manatee spotted in December 1979 in Crystal River, Florida and again in other rivers in 2005 and 2006.

At the time of the new sighting, it seemed like an anomaly. Although some Florida manatees have been known to travel hundreds of miles along the coast to places like Massachusetts and Texas, they had never been documented traveling to Cuba and aren’t known to cross large bodies of deep water.

“It was not only the first report of a Florida manatee resident in Cuba but, to me, it was also a revelation that the waters of the Gulf of Mexico and Florida Strait might be bridging or connecting, instead of separating, two populations,” Anmari Alvarez-Alemán, the Caribbean Director for Research and Conservation at the Clearwater Marine Aquarium Research Institute, told Mongabay.

Because there had been no other sightings, some researchers thought the manatee might have accidently wandered out of its Florida habitat and, by luck, stumbled into another one. But what if this was a sign of previously undiscovered migration patterns? Could manatees be traveling to Cuba regularly?

In the years since that sighting, several other Florida manatees have appeared in different parts of the Caribbean, challenging what researchers know about the animal’s behavior and what it might say about changing ecosystems along Florida coasts.

Dwindling habitats, and other theories

There are two subspecies of the West Indian manatee (Trichechus manatus): the Florida manatee (Trichechus manatus latirostris) and Antillean manatee (Trichechus manatus manatus), which is found around Caribbean islands, Central America and the northern coasts of South America. Previously, researchers believed the strong currents of the Florida Strait were keeping the two subspecies separated.

Manatees live in warm coastal waters and come into rivers and bays to drink freshwater. In Florida, popular areas like the 251-kilometer (156-mile) Indian River Lagoon have suffered from habitat degradation, including algae blooms and a loss of seagrass bed feeding sights.

While Florida manatee populations have been going up in Florida, last year also saw a historically high number die from boat accidents and starvation, among other things, causing officials there to start a feeding program to supplement the seagrass beds.

“There is a lot of evidence showing the decrease in seagrass density, not only in the east but in the west coast of Florida,” Alvarez-Alemán said.

Many manatees have been forced to travel farther south to find vegetation, potentially exposing them to temperatures below 68⁰ Fahrenheit (20⁰ Celsius), which can induce deadly “cold stress.” Traveling to Cuba might be their solution to — or a symptom of — that problem.

Another possible explanation for the manatee sightings is that the animal has always migrated to different parts of the Caribbean, but a lack of information-sharing between countries, coupled with inadequate technology, may have hindered the discovery.

Today, more fishermen travel with cell phones and can capture photos and videos of the marine life while out on the water — something that wasn’t as common several years ago.

“Before we had cell phone technology available, perhaps these sightings were taking place in places where people weren’t able to share information,” Alvarez-Alemán said. “We need to keep doing research in order to see if this is the case or if this is something taking place because of changes to the habitat in Florida.”

More sightings, more research

After the 2007 sighting, a decade would pass before another Florida manatee was reported in Cuba. Like the first sighting, it was a mother and a calf with enough scarring that researchers could confirm the adult had come from Florida. Earlier that year, a photo had been taken of it in Fort Myers. The animal would also be sighted in Cuba in January 2020.

Between November 2020 and February 2021, two Florida manatees appeared not in Cuba but in Cancún— the first-ever sightings in Mexico. Researchers noted that they were larger than the local manatees, and had several scars on their bodies that are rarer in those waters, as boat accidents don’t affect animals in Mexico as often. They were also extremely friendly like Florida manatees, coming close to humans.

This February, another Florida manatee was spotted by fishermen in Santa Cruz del Norte, Cuba, where the first sighting had originally been reported back in 2007. The fishermen were surprised by how friendly it was, and gave it freshwater from a hose.

“All it did was drink water from a hose that the fishermen were giving it,” Aniushka Borroto Bermúdez, a resident of Santa Cruz del Norte, told Mongabay. “I was amazed that such a big animal, one that seemed so alone, could interact so well with humans.”

The increase in sightings has encouraged Alvarez-Alemán and other researchers to step up their efforts, carrying out increased monitoring and genetic testing to determine whether the different subspecies are interbreeding more than previously thought.

“We’re trying to piece together information and obtain photographs from areas outside of Florida to compare them to our database,” Kari Rood, of the Florida Fish and Wildlife Conservation Commission’s Florida Manatee Program, told Mongabay.

The jury is still out on what Florida manatees are doing in different parts of the Caribbean, and what it means about previously unknown evolutionary trends. But with these efforts, an answer may come soon.

“As partnerships grow stronger and we’re able to obtain information more quickly,” Rood said, “we can better identify the connections that are being made.”

Citations:

Alvarez-Alemán, A., Beck, C. A., & Powell, J. A. (2010). First report of a Florida manatee (trichechus manatus latirostris) in Cuba. Aquatic Mammals, 36(2), 148–153. https://doi.org/10.1578/am.36.2.2010.148

Alvarez-Alemán, A., Austin, J. D., Jacoby, C. A., & Frazer, T. K. (2018). Cuban connection: Regional role for Florida’s manatees. Frontiers in Marine Science, 5. https://doi.org/10.3389/fmars.2018.00294

Castelblanco-Martínez, D. N., Alvarez-Alemán, A., Torres, R., Teague, A. L., Barton, S. L., Rood, K. A., Ramos, E. A., & Mignucci-Giannoni, A. A. (2021). First documentation of long-distance travel by a Florida Manatee to the Mexican Caribbean. Ethology Ecology & Evolution, 1–12. https://doi.org/10.1080/03949370.2021.1967457

This article by Maxwell Radwin was first published by Mongabay.com on 29 April 2022. Lead Image: An Antillean manatee. (Photo courtesy of Patrick M. Rose/EFE).

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