Warm water discharge creating trouble for manatees?

Goose, the wayward manatee rescued last year from the Cooper River, has been netted there again. The “sea cow” was one of four trapped recently and relocated to Florida after surrounding waters became too cold for them to survive.

The water temperature was fine where the manatees were: in the warm water discharge from the KapStone Paper and Packaging mill in North Charleston.

However, the surrounding waters are cooling, threatening the manatee.

That might be an emerging problem.

Last year, Goose had to be pulled from the discharge waters below Williams Power Station in Bushy Park in Goose Creek.

Five manatee have had to be rescued in the Cooper in the past two years. Before that, only one or two had to be rescued from S.C. waters across a decade or so, said Jim Valade, U.S. Fish and Wildlife Service manatee rescue coordinator.

“We haven’t seen manatees using Cooper River warm water discharges like this in the past. We’re not sure why there’s been a change in use,” he said.

Meanwhile, wildlife biologists and KapStone are watching for a fifth manatee that swam away from the rescue attempt and apparently has returned to the discharge. They are looking at another potential rescue attempt.

Last year, a second manatee was spotted but swam away. What happened to it isn’t known.

In Florida, the discharges have become a winter haven for the species. Hundreds at a time gather during cold spells at power plants.

Whether that could happen along the industry lined Cooper River isn’t certain. The jump in numbers in the past two years could be an anomaly.

But the difference in water temperature between Florida and here could be life and death for the protected species.

The animals can’t survive for very long in water temperatures lower than 68 degrees. Charleston Harbor waters are now in the 50s.

“It’s really hard to say if it’s a sign of things to come. It’s possible it is,” Valade said. “Clearly, we need to be keeping a close eye on this.”

Extending their winter range?

Manatees are bulbous, seal-like creatures. Their whiskery, puppy-like faces and lolling, seemingly serene behavior often delights onlookers.

About 50 are thought to migrate from Florida to the Lowcountry each summer, about 1 percent of the population, and then return to the Sunshine State when S.C. waters cool.

Occasionally, however, stragglers that lull in warmer pockets of water here get trapped.

As their numbers grow in Florida, concern is growing among wildlife biologists that manatees, like other subtropical species, could be trying to extend their winter range.

South Carolina is among a number of states in the region that now keep tabs on the animals into the colder months, said Erin Weeks of the S.C. Department of Natural Resources.

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

The coastal animals frequent the Cooper River and Tailrace Canal. They have been spotted inland as far as the Marion-Moultrie lakes.

Partly the problem is the Lowcountry — with its relatively clean water and thick vegetation for food — is just too good for them, Valade suggested.

“We’re seeing animals attracted to that.”

‘Pretty feisty’

When he was pulled from the frigid water of the Cooper River last December, Goose was emaciated and struggling. This time, “he was pretty feisty when we caught him. He didn’t look the worse for wear,” Valade said.

After Goose recovered last winter, he returned to the estuaries around Charleston Harbor in May with a radio transmitter attached, providing researchers with valuable data about species movements. But the transmitter eventually detached.

As with last year, the recent recovery was coordinated among federal and state agencies, the company and a Sea World Orlando team. It was a remarkable effort to pull out as many as four large animals without injuring them, Valade said.

In Florida, wildlife agencies have negotiated agreements to protect the species while they mass at power plants. Those agreements include the utilities agreeing not to shut down the discharge while manatees are massing. Fishing also has been discouraged in the waters in order to keep out boats that could injured the manatees, Valade said.

“If we see an increase in the animals in South Carolina, we'll have to work with the state and industry partners,” Valade said.

This story was originally published January 2, 2017 at 5:32 PM with the headline "Warm water discharge creating trouble for manatees?."