The Truth About Turtle Tears

The sea turtle moms are really popping up like crazy on Juno Beach!  The loggerheads are here in full force and the green sea turtles are getting into the swing of nesting as well.  The leatherbacks are still here, finishing out their nesting season with a bang. This week we encountered a couple previously tagged leatherbacks.  This was the first time we’d encountered them nesting on Juno Beach this season, and one was a new girl for our database.  First this week we had a midnight nester, Charlie.  Charlie measured at 146 cm, or about 4.8 feet long.  She was a slow nester, giving us lots of time to work with her.  Charlie was first tagged in 2006.  Charlie was interesting for a couple of reasons.  She had a gooseneck barnacle on one of her flipper tags, something unusual for our nesting population, but commonly found in leatherbacks that nest in the Caribbean.  Charlie also had very large salt gland secretions, or tears hanging off her face.  Leatherback sea turtle tears are highly viscous, with a consistency best described as what one would imagine troll snot to be.  All sea turtle species secret these salty tears, but the tears from the leatherbacks are the largest, longest, and certainly the goopiest.

 Charlie nesting, with salt glad secretion ‘tears’ visible.

Why the tears?  Sea turtles secret excess salt from the salt glands behind their eyes.  This is a necessary adaptive trait that allows them to live in the salty ocean and maintain lower concentrations of salt inside their bodies.  The salt level of sea water would be lethal to sea turtles if it was matched in their internal salinity.  Maintaining water balance is important for leatherbacks because of their salty salt water habitat, and because they have a salty diet as jellyfish, their favorite food, are mostly sea water.  The tears are more obvious when a sea turtle is nesting, but they are being secreted all the time to maintain this water balance.

A closeup of Charlie’s tears hanging off her face.  She’s not sad! Sand gathering on the faces of nesting females make the tears more obvious.

Our research team is processing salt glad secretion samples to look for contaminants known to diminish sea turtle health and examine the relationship between the presence of contaminants found in the tears to the level of found in the blood.  Collecting the tears is a quick, non-invasive process.  We hope to be able to move to this minimally invasive technique to further reduce our impact on individuals encountered nesting while still being able to monitor the health of our leatherback population as a whole.


Left: Lemon taking a break from the hard work of nesting.  Center:  Lemon pauses while covering her nest.  Right: Lemon front flipper covering.

Later in the week we encountered a pint-sized leatherback named Lemon.  This is our first encounter with the nesting mother.  At 143 cm or just over 4.6 feet, she’s on the smaller side, but was very vocal while exerting herself in her nesting effort.  Lemon came up unusually early in the night, nesting before 10:00PM.  Based on our workup of her we suspect that she still has a few clutches left to lay this season.  We’ll keep patrolling to catch the return of this little girl, or any other leatherback mom, to Juno Beach!

Disclaimer: All marine turtle images taken in Florida were obtained with the approval of the U.S. Fish & Wildlife Service (USFWS) and the Florida Fish & Wildlife Conservation Commission (FWC) under conditions not harmful to this or other turtles. Images were acquired while conducting authorized research activities pursuant to FWC MTP-17-211.