Sunday 14 October 2018

What manatees do during hurricane season

The gentle giants have ended up in golf courses, forests, and backyards.

On Wednesday afternoon, Hurricane Michael slammed into the western coast of Florida. It was, as my colleague Robinson Meyer described, “one of the most damaging and powerful storms ever to wallop the continental United States.” Several neighborhoods were devastated, more than a dozen people were killed, and hundreds of thousands were left without power.

And in the midst of all the destruction, a pair of manatees living in Crystal River, a city on Florida’s northwest coast, followed the rising flood waters into parts unknown. As the waters receded, the duo—a mother and calf—found themselves trapped in a canal.

Fortunately, the local people are well-practiced at rescuing manatees. A large team, including Florida Fish and Wildlife officials, sheriffs, and community volunteers, herded the pair into open water, draped them in nets, and hoisted them onto a gurney—no small feat for an animal that can weigh up to 1,300 pounds. They then drove the animals back to the river, and released them.

This happens a lot.

A manatee and her calf at Crystal RiverSCOTT AUDETTE / REUTERS
Crystal River describes itself as the manatee capital of the United States, and is home to hundreds of these large, endearing mammals. Manatees have famously gentle dispositions, and spend most of their lives slowly punting along shallow water with their flattened tails in search of sea grass to graze upon. They’re endangered, and although their numbers have increased in recent years, there are just over 6,000 individuals left. And many of them live in areas that are increasingly buffeted by intense tropical storms.

Being a tropical species, manatees do have some experience with major storms. Based on data from GPS tags, scientists have shown that they tend to ride out storms by hunkering down in sheltered cays. Still, storm surges—the rapidly rising waters that accompany hurricanes—can sweep them out of their safe zones and carry them to unfamiliar locations. And even if they aren’t swept up, they’ll sometimes go exploring in the storm’s aftermath, and become trapped when the high waters recede. They’ve ended up in people’s backyards, in drainage ditches, and in the middle of roads.

In 2016, after Hurricane Hermine, seven manatees became stranded in a pond at Crystal River’s golf course. At first, no one even knew how many there were. Manatees might not seem difficult to spot, but they are quiet, slow, and frequently found in dark water. When they come up for air, they break the water surface with just the tips of their nostrils, and then only for a moment. “It’s not like a dolphin that’s coming up and down,” says Cathy Langtimm from the U.S. Geological Survey. “They can be quite stealthy.” There have been situations when teams have rescued groups of marooned manatees only to later find that they somehow left an animal behind.

After counting the golf-course-stranded manatees with a drone, a team of rescuers went into the pond with kayaks and banged their paddles to herd them into one corner. They then encircled the animals with nets, pulled them out, moved them into a large trailer, and returned them to the river.

Meanwhile, another pair—a mother and her calf—had become stranded in a forest. “It was just by luck that someone was clearing a logging road and saw something moving,” says Margaret Hunter from the USGS. “They weren’t really underwater any more. They were sort of wallowing in a mud puddle.” They were dehydrated and sunburnt, but again, both animals were saved.

That’s not always the case. Last December, another pair of manatees drowned in the same golf-course pond, after swimming over a land bridge that had been destroyed by Hurricane Irma. And there are likely many deaths that are never recorded.

Sadly, these slow-moving animals are so often hit by boats that scientists can identify individuals by the scars on their backs. For decades, researchers have used this technique to track the animals over time. Langtimm and her colleagues have used that data to show that manatee survival rates drop after major storms. It’s not clear why. They might get hit by debris in the water. They might get disoriented, head too far out to sea, and die from exposure to cold water. Even once the skies have calmed, manatees face ongoing threats, including boat collisions, entangling fishing lines, and blooms of toxic “red tide” algae.

Still, the team at Crystal River and surrounding areas do what they can for animals affected by storms and other dangers. So far, they’ve rescued over 150 individuals. “We’ve got a team that’s well trained and the state has a lot of these operations,” says Langtimm. “The best thing people can do [after a hurricane] is to keep watch for manatee activity in unusual bodies of water, and to call the Fish and Wildlife Commission if you suspect something.”

(Source: The Atlantic)

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