October through December is the time of year when sea turtles experience cold stunning. For the past 30 years the numbers have been on the rise. Climate change appears to be a major factor in this increase. The waters are staying warmer longer, and getting warmer farther up the coast towards Maine. The Kemp’s Ridley migration has extended into the Gulf of Maine. As long as the water is warm, the turtles stay longer, and when the temperatures drop they travel south, but because of their location, they can end up in Cape Cod Bay. The decrease in temperature along with strong winds cause them to stun and they are unable to swim. They get trapped in the hook shape on the bay and can’t escape. When they wash up on shore, they are hypothermic, and can appear dead.
Sea turtles are ectothermic (cold-blooded), and can’t regulate their body temperature if the water temperature drops below 50 degrees. They become lethargic, unable to swim, and float to the surface where they become vulnerable to boat strikes, or wash ashore with the tides and become stranded. Their condition is critical because by the time they strand they have had weeks of hypothermia and an inability to feed. Cold stunning can lead to shock, pneumonia, frostbite and potentially death.
On Cape Cod we mostly see Kemp’s Ridley turtles (rarest and most endangered), Green turtles and Loggerheads. Each year the number of turtles found varies. In 2019, 300 turtles were recovered. In 2014, 1200 were recovered, a record that still stands. If the turtles have an internal temperature above 50 degrees, they have a greater chance of survival. If their internal temperature is below 30 degrees there a poor outcome. BY late December most turtles found do not survive. On a good year 70-80% of the turtles can be saved.
Mass Audubon Wellfleet Bay Sanctuary has 250 volunteers who patrol the beaches from October to December looking for turtles. Two volunteers, Tom and Margi O’Neill have been patrolling the Sandy Neck beach and dunes since 2015. When the wind is blowing North to Northeast, and it’s just after high tide (many times in the middle of the night), they don their turtle hunting gear. These outfits are a combination of rubber boots, ski clothing and rain gear. Turtle searching is a cold, wet job. They have spotlights and headlamps and search through seaweed, wet sand and the nasty foam that sticks to all their clothing. They have to go up into the dunes and check the scrub brush. It involves concentration and attention to detail. The biggest fear they told me is “missing one and leaving it behind”. Their most memorable turtle found was a 90 pound loggerhead. The most common turtle they rescue is the Kemp’s Ridley, and one night they found twelve.
Searching is repeated by on all the Cape Cod Beaches at each high tide every day during the season. A huge thank you to all the volunteers and to Bob Prescott for establishing this program and contributing to this article. What do you do if you find a cold stunned turtle?
- Move it carefully to the above high tide line
- 2) cover with seaweed, dry seaweed if possible
- 3) Mark with a vertical stick
- Call 508 349 2615. Ext 6104
DO NOT MOVE IT. If you bring it into your warm car, you can kill it.
These turtles are treated at the National Marine Life Center in Bourne, The New England Aquarium and Mystic Aquarium. They first are put in a dry tub and evaluated for vital signs and any additional injuries. They are warmed slowly with heat lamps, blankets and warm fluids. They are released when they can swim and eat normally. They are released both up here and in Florida. Despite all this effort, another 10-20% of turtles die in treatment.
Another turtle species, the endangered Diamondback Terrapin, experiences “cold shock” versus cold stunning. Many of the symptoms are the same, but it is usually caused by a disturbed dormancy (brumation). These turtles live in brackish water in estuaries and marshes. They have specific habitats in Wellfleet, Wareham, Sandy Neck, and Orleans.
Terrapins for the first two years are relatively freeze tolerant. If they get washed ashore in a hibernated state, then they need to be rehabilitated. If a terrapin is floating in the water, that terrapin is in trouble. Many times, when they are in shock, they are predated by other animals and have injuries that include loss of limbs and facial damage.
IN 2019 the Cape Wildlife Center cared for 30 terrapins. They were slowly warmed, had any injuries treated, and surgery if necessary and given nutrition. In the Spring they were released once the water temperature approached 60 degrees. These terrapins over-winter and can be kept for 6 months.
If you find a stranded terrapin, or wish to donate to help with their care, call the Cape Wildlife Center 508 362 0111 9-4 seven days a week or visit www.capewildlifecenter.com .
Caryn Ritchie is the volunteer coordinator for the Cape Wildlife Center and holds both a Massachusetts State Wildlife Rehabilitation License and a Federal Migratory bird permit.