Don’t water the manatees, federal wildlife biologists are stressing. The slow-moving mammals ought be well on their way back to Florida by now, but recent reports indicate they might be overstaying their Lowcounty summer haunts.

S.C. manatee sightings

72 — Number of 2013 sighting reports statewide through Monday.

48 — Charleston County reports.

5 — Berkeley County reports.

Source: U.S. Fish and Wildlife Service.

That could kill them. People “watering” them, or supplying a fresh water feed, might be keeping them around.

“Providing manatees with food and water is not only a violation of federal law, but it also creates significant problems for the manatees, as they will easily acclimate to hand-outs of food and fresh water,” said Jennifer Koches, of the U.S. Fish and Wildlife Service.

The water temperature in Charleston Harbor on Monday was 68 degrees — a drop-dead point for manatees. They can’t survive in water that cold for very long. The animals usually move when temperatures drop below 70.

At least six sightings have been made in the state in the past week or so, three in Charleston. The most recent report was Friday — in Horry County to the north. A few of those sightings were made near running water, Koches said.

The animals tend to turn up near docks, particularly where a freshwater spigot runs. It’s enough of an attraction to keep them around even as waters chill, especially if they’re getting fed too, said Katie Tripp, Save the Manatees science and conservation director.

“Those manatees need to be getting the signal that’s it’s time to go home,” she said. For people to leave water running or feed them, “is like holding open the buffet table too long.”

Manatees are bulbous, seal-like creatures whose lolling, seemingly serene behavior has delighted onlookers for generations. They are said to have inspired the myth of mermaids.

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.

Sightings in the Lowcountry have increased dramatically in recent years, but wildlife experts can’t be sure if the manatees themselves are adding population, or people are becoming more aware of them and reporting.

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

In late November 2012, a dead manatee was discovered in Lake Marion. It apparently had gotten trapped in the lake and died of the cold.

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