Why Do Turtles Cry

As I paddle out clumsily to Flat Island in Kailua, I hear a goodbye call from the shore, “go, Turtle!”

My friend’s husband has nicknamed me “Turtle” after we went on a few surf sessions together and he noticed that I look very much like a turtle as I struggle to paddle out.

It turns out, I may have something else in common with turtles. 

It turns out… turtles cry. A lot. 

I’m currently reading “The Blue Machine: How the Ocean Works” by Helen Czerksi, and as the author explores the salinity of the sea, she also mentions the fact that turtls cry. A lot.

What Do Jellyfish Have to Do With Turtle Tears

Turtles and I may both cry a lot, but we definitely cry for different reasons.

My tears are the result of frustration at work, fighting with friends, watching a sad movie, watching a happy movie, sometimes listening to a song about an old man whose partner has died…

You get the idea. 

Turtles cry because they’re eating.

No, really! The example that Czerski uses is a turtle eating jellyfish. Less than one percent of jellyfish is organic material and a turtle (the author uses a leatherback as an example) must eat 80% of her body weight. 

Jellyfish have the same salinity as the ocean itself, so as you can imagine, this results in a TON of salt being ingested by turtles. 

It’s not just jellyfish, either. Other marine substances and creatures have the same salinity as the sea. For example, algae. 

To avoid ingesting all of this salt (which would kill the turtles), they expel it back out in the form of tears.

How Do Turtle Tears Work, Exactly?

This part is super cool - thank you to Mariluz Parga of “Submon” who posted here. She explains how sea turtles’ esophagi and lacrimal glands work.

I recommend checking out her post to see some visuals. To summarize, sea turtles’ esophagi have uniquely developed muscles and are lined with “spines” called papillae. The muscles of the esophagi are able to remove sea water as the turtle devours something like a jellyfish while the papillae spines ensure that the food does not escape with the water.

At the same time, lacrimal glands produce viscous tears, releasing salt through these glands. This process of releasing salt is otherwise known as electrolyte homeostasis. According to Czerski, turtles cry around eight liters of tears every hour. Still, there is a lot to learn about these glands according to one article from the National Center for Biotechnology Information.

All in all, I am happy that the tears you may see in turtles’ eyes has nothing to do with heartbreak (though the amount of plastic floating in our oceans, deceptively similar in appearance to the jellyfish they eat is heartbreaking).

The net time I’m seasoning a meal, I’ll certainly think about what it would be like to survive in an environment where my body had to optimize itself in order to expel enough of what it was intaking to survive.