Why manatees need humans to slow down and pay attention.

Calliope, an orphaned manatee that had spent three years in Cincinnati for rehabilitation, mingles with others of her kind moments after being released back into the wild at Three Sisters Springs, in the Crystal River National Wildlife Refuge in Florida on Feb. 13, 2024. Since the start of the year, at least 31 of the sea cows — as the manatees are colloquially known — have been struck and killed by boats in Florida. (Jason Gulley/The New York Times)

By JOHNNY DÍAZ

In early March, a female manatee measuring 9 feet 5 inches long that was injured after being in the path of a boat was rescued in an estuary in Cape Coral, Florida, which is known to be a winter habitat for the rotund water mammals.

It’s not clear where the boat and the manatee collided, but the mammal suffered injuries to its ribs and lungs, which led to its death 10 days later at a rehabilitation center.

It was among the latest encounters between humans and manatees that contributed to the death of one of the aquatic animals.

Since the start of the year, at least 31 of the sea cows — as the manatees are colloquially known — have been killed in such collisions in Florida. The risk of such accidents grows in the spring, when the warmer weather attracts more boaters as manatees become more active in rivers and shallow coastal areas, experts say.

Cora Berchem, a manatee research associate for the nonprofit group Save the Manatee Club in Longwood, Florida, said “manatees are migrating back out to their summer ranges and can pretty much be found in almost all waterways in Florida.” Boaters should exercise more caution, she said, particularly until the winter season when manatees return to their sanctuaries in calmer waters around November.

The mammals are grayish brown with sparse hair across their bodies. Adults average 9 to 10 feet long and weigh about 1,000 pounds.

Last year, there were a total of 632 manatee deaths statewide, which was higher than for each of the previous two years, when 555 and 565 manatee carcasses were recorded.

Collisions accounted for 25% of their deaths in Florida last year, with other contributing factors being a colder winter and a red tide bloom, according to the Florida Fish and Wildlife Conservation Commission.

“Coexisting with manatees in Florida is a big topic, and with the human population increasing daily, sharing the habitat with manatees has become a growing problem or at least a topic that requires increased attention,” Berchem said.

Manatees are vital in Florida because they benefit the ecosystem by grazing on both native and invasive plants and help to keep the waterways clear, she said. Manatees are also economic drivers in the state because of their popularity.

“Florida lives from tourism, and many visitors come to Florida to see manatees,” she said.

As recreational boating season ramps up for the spring and summer in coastal areas along the Southeast, here are tips from manatee and wildlife experts on how humans can better protect manatees and coexist with them.

Where are they?

The Florida manatee is found in the state’s coastal waters, rivers and springs from the tip of South Florida to the Panhandle and Atlantic coasts.

Although the Florida manatee is a beloved unofficial mascot associated with the state, the large slow-moving mammal is known to travel up the eastern coastline into Georgia, the Carolinas, and as far north as Massachusetts during the warm months, officials said.

In the Gulf region, Florida manatees travel west through coastal Louisiana and are occasionally sighted as far west as Texas.

There are about 8,350 manatees in Florida, according to the U.S. Fish and Wildlife Service.

The sea mammals are a tourist attraction at a lagoon in Lake Worth, Florida, where dozens of them bask in the warm water discharge from a nearby Florida Power and Light power plant during the area’s manatee season, which runs from Nov. 15 to March 31.

First, slow down.

The animals, which cruise slowly by moving their tails and flippers, and sometimes idle just beneath the surface, are vulnerable to scarring and death because of collisions with boats.

Manatees typically swim about 3 to 5 mph but they can reach speeds up to 20 mph in short bursts. Recreational boats usually cruise between 15 and 30 mph.

“People can help manatees by observing slow and no-wake zones, especially in manatee protection zones,” said Elise Bennett, a lawyer and director for Florida and the Caribbean at the Center for Biological Diversity, a nonprofit wildlife conservation group.

She noted that Florida each year loses about 100 manatees to boat crashes.

From April 1 through Nov. 15, seasonal manatee zones require boaters to slow down in certain areas to prevent animals from being injured or killed by motorboats or personal watercraft, according to the Florida wildlife commission.

Experts also suggest that boaters use propeller guards on their vessels to better shield manatees from injury if they are hit.

Avoid shallow areas.

Manatees are plant eaters known to forage for food and rest in shallow waters, such as canals and springs, so boaters should avoid traveling in areas with sea grass.

“Look for large circles on the water, also known as manatee footprints, indicating the presence of a manatee below,” the Florida wildlife commission said.

The commission also suggested that boaters wear polarized sunglasses, which can reduce glare coming from horizontal surfaces, to better spot manatees underwater.

Look, but don’t touch.

Whether boating, paddling, swimming or diving in the wild, people visiting manatee habitats should not feed or touch manatees, even though they may naturally approach people.

Rather, they should give “the manatee sufficient space” and not interfere with its natural behavior, Berchem said.

“Manatees are naturally very curious and will oftentimes approach, but the behavior should not receive positive reinforcement,” she added.

Interacting with manatees can lead them to lose their natural fear of humans and boats.