Rehabilitators help cold-stunned turtles recover
PORT ARANSAS – More than 700 sea turtles were found frozen into a comatose-like state along the Texas Gulf Coast this winter.
The National Oceanic and Atmospheric Administration’s Galveston lab took in 26 turtles from Matagorda Bay in a single day in November.
Volunteers and scientists were able to rehabilitate most of the turtles found in the hypothermic state, commonly referred to as cold-stunned.
A quick drop in bay temperatures has always been a hazard for the cold-blooded creatures, who cannot warm themselves. But scientists have linked the uptick in the number of cold-stunned turtles to an increase in warming Gulf waters and a resurgence of green turtles in Texas.
While this winter brought a record number of cold-stunned turtles onto the shores of Massachusetts, fewer turtles were affected in Texas than last winter, when 1,181 cold-stunned turtles were found.
Most of the turtles found washing up on beaches and floating in the bays in Texas were threatened juvenile green turtles, said Donna Shaver, chief of the Division of Sea Turtle Science and Recovery at Padre Island National Seashore.
Though few green turtles are hatched in Texas, they migrate up the coast to feed on sea grasses in the bays. Instead of migrating south with the changing seasons, the turtles have stuck around with the warmer fall water temperatures, Shaver said.
When a cold snap hits, such as the ones in November and January, the dinner plate-sized juveniles can’t escape the cooler bay waters because of a lack of breaks in barrier islands along the Texas Gulf Coast.
The turtles become immobilized.
« When it gets very cold, their physiology just shuts down, and they will float to the surface, » Shaver said. « They’ll either be found bobbing at the surface or washed ashore from prevailing winds. »
If they’re not located quickly, the turtles can succumb to boat strikes, predatory animals or exposure to the elements.
Of the 705 turtles found cold-stunned in Texas, 184 were dead, Shaver said. Others died during rehabilitation.
Scientists and volunteers at rehabilitation centers, such as the Animal Rehabilitation Keep in Port Aransas and Sea Turtle Inc. in South Padre Island, work around the clock to take in cold-stunned turtles, heat them up and release them back into the sea.
The Animal Rehabilitation Keep took in so many cold-stunned turtles that they overflowed into the halls. Some of the scientists at the Marine Science Institute in Port Aransas shared lab space with the turtles in rehabilitation, said Tony Amos, director of the Animal Rehabilitation Keep.
When the turtles first come in, they’re kept out of water and heated about five degrees at a time, said Jeff George, Sea Turtle Inc. executive director.
If the turtles are put into water right away, they could drown because they cannot lift their heads up to breath, he said.
As the turtles come out of the cold-stunned state, which can take anywhere from a couple of hours to a day, they begin to crawl around. One of the first things the turtles do is poop, George said.
« You have a whole host of volunteers to cleanup after them, » he said.
The turtles are then placed into rehabilitation tanks before being released back into the wild.
« When you put them in the ocean, they take off, and there’s no turning back, » George said. « They’re gone. »
Treating large numbers of cold-stunned turtles has become an annual event in many parts of the country.
Because of the record number of turtles cold-stunned in Massachusetts this year, 50 of the 1,240 turtles found were sent to Galveston to recover, said Kate Sampson, National Oceanic and Atmospheric Administration’s sea turtle stranding and disentanglement coordinator for the Northeast.
Unlike Texas, the majority of turtles frozen in Massachusetts are endangered Kemp’s ridley sea turtles. The turtles get to Massachusetts through the Straits of Florida and are caught up in the Gulf Stream, which takes them up the north Atlantic Coast, said Ben Higgins, research fishery biologist and sea turtle program manager of NOAA’s Galveston lab.
Kemp’s get pushed into Cape Cod Bay in the summertime. Because the bay opens to the north, the turtles get trapped by blue northers.
« The water temperature drops very, very quickly. It gets cold really fast, » Higgins said. « The turtles there literally come in with frostbitten flippers and freezer burn on their shells. »
Kemp’s being treated for hypothermia in Massachusetts typically suffer from more severe symptoms than the green turtles found in Texas.
The Kemp’s have been washed up on shores of Cape Cod in freezing or below-freezing weather and have pneumonia, are dehydrated and emaciated, Sampson said.
Their body temperature can be as low as 37 degrees, and their heart rate as low as one beat per minute.
While the stranded green turtles in Texas take days to weeks to treat, the Kemp’s ridleys in Massachusetts take weeks to months to recover.
The 50 turtles sent from Massachusetts to Galveston are not expected to be released until May, Higgins said. The Galveston facility is also still treating 40 green turtles found stranded in Texas.
While Kemp’s ridleys are found in Texas, they tend to follow shrimp and crab south as it gets colder, Higgins said. But green turtles are vegetarians and stay to munch on algae and seagrass.
While the number of turtles stranded in Massachusetts this winter is likely an anomaly, there appears to be more cold-stunned cases in the state every year, Higgins said. Among the factors causing the trend are a recovering Kemp’s ridley population and climate change, which not only causes warmer waters but can cause currents to change.
The problem is predicted to continue in Texas, too, making it especially important for boaters and beach-walkers to be on the lookout during cold periods, such as the one covering the state now, Higgins said.
« As humans, we’ve pushed these animals to the brink of extinction, and we have a responsibility to help them back to where they used to be, » he said. « And they’re a long, long way from where they used to be. »