When the water they are swimming in drops below 50 degrees suddenly it shocks sea turtles into a sort of catatonic state. They just float and wind up stranded on the shore where they can freeze to death, starve, or be eaten by predators. Right now conservation and rescue groups are recovering hundreds of stranded turtles a week in the Bay of Maine as juvenile sea turtles swim into it while it's warm and then get cold-stunned as the weather turns. Read more here.