Manatees are back Boaters urged to watch for poky giants

Manatees are annual visitors to the waters around Charleston as was this one which showed up at Fort Johnson. S.C. Department of Natural Resources/File

Coastal waters have hit room temperature and right on cue, the first manatee of the year has been spotted in the Charleston area.

The manatee was reported Sunday in the Cooper River near Bushy Park, said Al Segars, of the S.C. Department of Natural Resources. DNR maintains a website for manatee sighting reports.

Watch out, he and others say. The poky mammals need to surface to breathe, and boat propeller strikes are a leading cause of deaths. The coastal animals have been spotted inland as far as the Marion-Moultrie lakes.

Use common sense, look for large swirls or signs of movement in the water as you would watch for debris when boating, said Patrick Rose, of the Save the Manatee Club.

Some 50 or more of the “sea cows” make their way to South Carolina each summer from their wintering grounds in Florida, about 1 percent of the estimated population. About half turn up around Charleston.

Some think the numbers here are increasing as threats in Florida multiply, but nobody really knows.

Sightings have increased dramatically in recent years, but wildlife experts can’t be sure if the manatees themselves are increasing, or just the awareness of people reporting them.

They are an endangered species, and they are in jeopardy at both ends of their seasonal migration.

They roam tidal waters like dolphins to search for food, the same waters crowded by boats during the summer. Meanwhile, the last manatee seen last year was found floating dead in Lake Marion in November, evidently killed by colder water after getting trapped in the dammed Marion-Moultrie lakes.

In Florida, this year is shaping up to be the worst on record. About 10 percent of the population has been found dead so far — some 600 mammals — three years after 766 deaths became the worst year on record.

So far, 260 have turned up dead in the Gulf of Mexico in lower Florida, victims of a lethal “red tide” algal bloom. More than 150 have died in Indian River on the state’s east coast, from a cascade of problems following a severe cold snap three years ago and two blooms of different species of algae. The red tide and problems appear to be dissipating, said Rose of Save the Manatee, an aquatic biologist.

But the outlook for the animals there is “very guarded,” Rose said.

The phytoplankton species responsible for red tide is not known to be a problem in South Carolina waters, said Dianne Greenfield, phytoplankton ecology assistant professor at University of South Carolina. But the waters here are monitored for other harmful species, she said.

Meanwhile, warming waters could bring more algal blooms; that and rising seas could disrupt habitats. That’s among “a whole host of things that manatee and their habitat are going to face,” Rose said.

Reach Bo Petersen at 937-5744, @bopete on twitter or Bo Petersen Reporting on Facebook.