Everything you ever wanted to know about leatherbacks
First of all, Leatherbacks are GIANT. Our largest turtle measures more than 170 centimeters long - about six feet! They are mostly black with white and grey spots over their carapace, head and flippers. Leatherbacks are unique in that they do not have a solid bony carapace like other sea turtle species instead, their shell is composed of a thick layer of fibrous fatty tissue which contains a mosaic of tiny bones. Their carapace is rather soft and it sort of feels like the sidewall of a car tire.
Leatherbacks have giant front flippers that are almost as long as their body.
The jaws of the leatherback are specialized to eat they only prey - jellyfish.
Threats
Leatherbacks may be more susceptible to injury than other sea turtle species because they lack a true hard shell. Instead of a typical turtle ‘shell’ on their backs, leatherbacks have a thick layer of fibrous fatty tissue overlaid with a mosaic of tiny bones (separate from the underlying ribs), all covered by a thin, fragile skin. The main documented threats to leatherbacks include boat strikes, plastic ingestion, longline hooks and entanglement in fishing gear.
Recently we’ve begun to document injuries on leatherbacks that are nesting on our beach. We have seen some pretty severe fresh and healed wounds. Here we’ve included some pictures of Juno Beach nesting females, and each one has a unique story.
Hydra is a turtle that we first tagged in 2002. She nested once on our beach, but likely nested elsewhere in Florida that season. She had no injuries at that time, only her left rear flipper had a chunk missing from it, but it was not a fresh injury. This year however when Hydra showed up to nest, she had been through some major trauma. You can see wounds on her shoulder and carapace that are still raw and rotten. She still was able to nest successfully but her white blood cell count seemed rather high (indicative of infection) and we’ll be interested to see what the rest of her blood profile looks like when it is analyzed.
Hydra 04/29/2004
In a reversal of Hydra’s story, Delphinia was a turtle that we observed nesting in 2001 with terrible wounds around both of her front flippers. It looked like she had been wrapped up in ropes and fishing gear, and they had cut into her flippers and rubbed off her skin. At that time we noted all injuries and took pictures of her wounds. It really was a terrible sight. Delphinia came back in 2003 and we were happy to see that her wounds had cleared up, and although she was heavily scarred, she appeared to be ok and nested successfully twice on Juno Beach.
Pesca was observed once in 2003. She was one of our candidates for a satellite tagging program we were participating in. When we got close to her to tag her and attach the transmitter, we saw that she was completely bound by longline monofilament and still had a large hook in her shoulder. The monofilament was attached to the hook and went into her mouth, all the way through her digestive tract and was sticking out of her cloaca, which was also dropping eggs into her nest! We were able to cut much of the monofilament off and remove the hook, and we just hoped that the rest of the monofilament would work its way through her body and be expelled. Pesca was equipped with a satellite transmitter and we followed her movements for several months until her signal was lost east of the Grand Banks in the Northeast, where fishing by longlining is done intensively.
This male leatherback was first spotted at Oregon Inlet, NC. It had stranded on the beach and was barely alive.
Matt Godfrey and Wendy Cluse from the NC Wildlife Resources Commission responded to the stranding along with veterinarians from the area. The turtle was lethargic and was very beat up looking, with lots of cuts and scrapes. Because of the turtle’s severe injuries and lethargy (males are rarely found on beaches), it was decided it would be most humane to euthanize the turtle. A necropsy was done after the turtle died and along with other samples being sent for analysis, the stomach was sent to Niki Desjardin (our own Niki, finished her masters degree at Florida Atlantic University).
Here’s her report –
“ We all think it's pretty neat that leatherbacks can grow so large on a steady diet of jellyfish. However, because of this dietary specialization, floating debris in the ocean can cause major problems for these turtles. A few studies have reported plastic in the stomachs of leatherbacks. Some people have guessed that the turtles think floating plastic resembles jellyfish in the water and so they accidentally eat the trash.
I have been examining the gut contents of leatherbacks for my thesis project and have found quite a few interesting things. Many of them have had small pieces of plastic or plastic bags lodged in their intestines. Sometimes, the tissue in the intestine will recognize the foreign material and "package" it up within the lining of the gut. These small obstructions don't seem to hinder digestion too much. However, one turtle that recently stranded in North Carolina had a much more serious problem. As I worked my way down from the esophagus to the stomach, a large protruding mass became apparent. I cut away the tissue and realized that the large mass was a giant chunk of balled up plastic that was completely blocking the GI tract. I removed the mass, and it turned out to be larger than a football! When I unraveled the mess, the ball appeared to be made up of a large trash bag and a mylar balloon (the kind you fill with helium and give as gifts). Once all the plastic was spread out, it measured about 3 feet across and took up the whole table. This turtle apparently thought it was ingesting a yummy meal when it consumed this plastic trash.
Sometimes we don't think about the consequences of trash in our environment. If it doesn't bother us, what harm is it doing? Well, this story helps to illustrate that all of our actions have consequences. We should think twice before discarding trash and do our best to generate minimal amounts of waste.”
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.
