Although fewer sickly endangered turtles have been washing up on Cape Cod shorelines this week, the stranding season for the animals is not over yet.
A historic number of sea turtles have ended up on the shores this year, as the waters became more frigid and the weakened turtles could not find their way out of Cape Cod Bay.
Bob Prescott, director of the Massachusetts Audubon Society’s Wellfleet Bay Wildlife Sanctuary, said most of the weakened turtles that were floating in the bay in the past month have already been carried to shore by the tides — 1,200 of them. The previous record was set in 2012 with 413 turtles, Prescott said.
In the beginning of the season in mid-November, about 80 to 90 percent of the turtles were found alive, Prescott said. Now, as the end of the month approaches, about 50 percent of the washed-up turtles are alive.
Before Thanksgiving, he said, the Audubon Society was collecting more than 100 stranded turtles on some days. This week, they have collected about eight from Cape beaches.
The majority of the turtles that have been stranded on shore are small Kemp’s ridley sea turtles, a critically endangered species. The other species include green sea turtles and loggerheads.
The stranding season for Kemp’s ridleys ends when the bay freezes over, which typically occurs by Christmas, Prescott said. But this year, temperatures have been much warmer, prolonging their stranding season, which could last until the start of the new year, he said.
“We don’t see a front in the horizon that will drive the temperatures down, and we’re not getting these prolonged cold fronts,” Prescott said.
Prescott said the Audubon Society will continue to pick up dead Kemp’s ridleys through the winter, as many get stuck in salt marshes, under boats, or behind barrier beaches.
While the stranding season for Kemp’s ridleys is coming to an end, the season for loggerheads is just getting underway, Prescott said. About 20 loggerheads have stranded since the beginning of the season — two of which were found this week.
Prescott expects more loggerheads to wash up toward the end of December into January. Loggerheads tend to strand later in the season than Kemp’s ridleys because they are larger and less susceptible to the cold.
The largest loggerhead found in the state in recent memory was about 280 pounds and was found on an Eastham beach in early November, which officials said was unusually early for such a large turtle.
“It’s not over until it’s over,” Prescott said.Trisha Thadani can be reached at firstname.lastname@example.org.