A few months ago, my husband and I made our first trip to Cape Cod. We went after the summer tourist season had died down but before winter weather reached the area. Or I should say winter weather for Cape Cod. Since I’ve spent most of my life in the southeastern United States, New England’s fall felt more like winter to me. Nevertheless, I persisted.
We traveled all over Cape Cod visiting museums, historical sites, and, of course, the beach. One day we walked along the National Seashore. It was overcast and clouds hung low in the sky. The wind had picked up and was whipping around us, nearly penetrating my windbreaker and the many layers underneath. The ocean was fierce that day as white-tipped waves ran over each other trying to be first to reach the shore.
Despite the cold, the marine biologist in me couldn’t resist reaching a hand into that swirling grey water. And it immediately recoiled. I had expected it to be cold. But it was COLD. I marveled at the organisms that spent any period of time in that water.
I thought back to that afternoon on the Seashore a few days ago when I came across an article discussing the number of cold-stunned sea turtles that had been washing up on Cape Cod as New England’s winter weather truly hit the area.
Like all reptiles, turtles are cold-blooded. They rely on their environment to regulate their internal body temperature. This is the reason why you might see a lizard or snake sunning itself on a rock. It needs the sun’s rays to stay warm. If a reptile gets cold, then its body slows down. It won’t move as often, and its digestion will slow. It also can become more prone to infection as its immune system malfunctions.
If sea turtles spend too much time in colder water than they can handle – normally below 50°F (10°C), then their body goes through this same process. They are less active and become more susceptible to infections including pneumonia. They also float to the surface and may end up being hit by a boat. Often, these cold-stunned sea turtles end up washed ashore where, if they’re lucky, they will be found quickly by a volunteer who can get the animal to a special care center for rehabilitation.
As the ocean temperature drops, cold-stunned sea turtles are more likely to wash ashore off some shores – particularly Cape Cod. A recent news article stated that over 100 sea turtles had washed ashore between November 17th and 29th alone. Higher number of cold-stunned sea turtles have been documented in recent years than ever before. Why?
Part of the answer is climate change. But to understand how climate change leads to cold-stunned sea turtles we first need to discuss sea turtle migratory behavior. Like some other marine animals, sea turtles travel the currents in the pursuit of food. And many of them on this side of the world, including the critically endangered Kemp’s ridley turtles, migrate to New England in the summer from places as far away as the Gulf of Mexico for the food. As the temperature begins to drop, they leave the area to overwinter in warmer waters.
Now here’s where climate change comes in. A still common misconception is that climate change only leads to global warming. However, climate change is more than that. For example, it changes precipitations patterns so that you see droughts and floods. It also makes some things – like temperature more unpredictable.
In the Gulf of Maine, the water stays warmer longer making the sea turtles think it is still safe to stay there. Then the temperature changes suddenly before the turtles have time to get out of harm’s way. And we see more cold-stunned sea turtles that need our help.
Are we sure that climate change is a contributing factor? Could it just be that turtle populations are higher, so we see more strandings? Scientists considered that in their research and accounted for it. It wasn’t the reason (see the original paper below). They suggest that more than 2,300 Kemp’s ridley sea turtles may cold stun annually by 2031 due to climate change.
So, what can we do? If you live in an area where sea turtles may be susceptible to the cold, then keep an eye out when you’re on the beach. And if you do see a stranded turtle (or any animal for that matter) contact the proper authorities. Don’t try to release it back into the water. It should be examined by a professional to make sure it is healthy first.
Warming seas increase cold-stunning events for Kemp’s ridley sea turtles in the northwest Atlantic: link