The manatee

Looks like a fat seal with a whiskery puppy dog face.

Grows to more than a half a ton and 14 feet long.

Is among any number of marine, avian and other species that migrate in and out of the Lowcountry, moving in spring or fall when the waters warm or cool. Wildlife officials urge people to be alert for them, give them room.

Is a federal endangered species - fewer than 5,000 are known to exist; boat strikes are a major threat.

Of the 50 or more sightings made in South Carolina estuaries each year, nearly half are around Charleston.

Sources: U.S. Fish and Wildlife Service, S.C. Department of Natural Resources and Sea to Shore Alliance

MOUNT PLEASANT - On a busy holiday weekend like Labor Day, Shem Creek might as well be a water park. The usual bustle of shrimpers, anglers and paddlers is crowded by pleasure cruiser after cruiser.

"You have a lot of them moving at high speed" once they leave the creek, said resident Randy Friedman. So what he saw in the Mount Pleasant channel this week has him worried - manatee, a pair of them, frolicking at the surface. "I'm afraid one of them is going to get killed."

That's not a misplaced concern. The channel is a recently dredged, popular smaller boat route in and out of Charleston across Crab Bank from the shipping channel. No place for manatee, you would think. But they're there, like they are in the creek and all around the Charleston estuaries, and they won't be headed out until the water cools.

Four manatee in a group were reported sighted in Charleston Harbor on Thursday, among 84 manatee reported so far this year, said Jennifer Koches, of the U.S. Fish and Wildlife Service. That number might include some repeated sightings of the same manatee.

The bulbous, seal-like mammal with the puppy dog face is a summer visitor to the Lowcountry, migrating up from Florida wintering grounds. Some 50 or more sightings are reported each year, about half near Charleston. They like to loll on the surface and are slow swimmers, so boat strikes are a major threat.

So is feeding or offering water to the sea creatures. That encourages behavior that attracts them to marinas, putting them more squarely in harm's way.

So watch out, please, said Friedman, echoing wildlife biologists. The manatees are a federally endangered species; fewer than 5,000 are known to exist and the numbers are dropping.

They return to Florida each fall in a mass movement so distinctive that it's said from the air you could see a line of them swimming down the coast. But they don't usually head out until water temperatures drop below 70. The harbor temperature this week was still in the 80s.

"The (recreational) stress on the Shem Creek area is so much more than it ever was, and it's more dangerous for the animals," Friedman said. "The channel really needs a speed zone. But nothing is being done, and I'm afraid nothing will be done until one of these animals is killed."

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