More than 150 sea turtles were found frozen solid on Cape Cod shores in Brewster and Orleans Wednesday and Thursday after temperatures dropped to single digits overnight, according to a marine expert.
The turtles, all but four of which were Kemp’s Ridleys, were most likely caught out on sand flats, making them more susceptible to the cold temperatures, said Jenette Kerr, spokeswoman for the Massachusetts Audubon’s Wellfleet Bay Wildlife Sanctuary.
“The flash freezing that occurred quickly overnight left the beaches all frozen up,” Kerr said. “Sadly, everything coming in this morning were like ice cubes.”
Most of the 82 turtles that washed ashore Wednesday night after the 10 p.m. high-tide were found alive, Kerr said, but nearly all of a second group of 87 found on Thursday night did not survive.
Three of the turtles were Green turtles, and another one a Loggerhead, Kerr said.
According to the National Weather Service, temperatures in Hyannis Thursday at about 3 a.m. were 22 degrees, and had dropped to 17 degrees by 7 a.m.
The water was in the upper 40s Thursday, Kerr said; turtles begin to shut down when the water hits 50 degrees, and they are vulnerable to the wind, waves, and tides.
Kemp’s Ridleys in particular are more vulnerable in such frosty conditions, Kerr said, because they are the smallest of its kind, and they are considered one of the world’s most endangered sea turtles, especially in Massachusetts waters.
Many of the turtles can contract pneumonia as well, Kerr added.
Reports of stranded turtles were first called in Wednesday night after the 10 p.m. high-tide, Kerr said. But by Thursday morning, beach walkers and Wellfleet Bay Wildlife volunteers spotted dozens more, most of them completely immobile.
The turtles that survived were immediately put into boxes and transported to the New England Aquarium where they will go through a gradual re-warming process.
After the turtles return to a healthy state, they will be flown to warmer waters anywhere between South Carolina and Florida, Kerr said. Turtles that stay in the aquarium due to illness or injury will be released back into Cape Cod waters in the summer.
Turtle strandings are a seasonal occurrence that begin around November, Kerr said, but have been increasing over the past few years.
“Because sea turtle conservation has been more successful, there are more successful hatchings, so we are probably seeing the result of 10 to 15 years of success at the nesting beach level,” Kerr said. “Temperatures have been increasing, so more turtles are probably hitting colder waters unexpectedly, becoming trapped in [Cape Cod] when they go south.”
But Kerr said there “is no hard answer” as to why more and more turtles are washing ashore.
During the 90s, turtle strandings started to become a phenomenon, with several hundred occurrences; in 2014, the Massachusetts area had 1,200 turtles wash ashore, Kerr said.