Leatherback Nesting Season Week 8 Update: Body Condition Study

This has been a special and extremely exciting week for our night crew on Juno Beach.  In collaboration with Upwell, a California based marine research and conservation 501(c)3 nonprofit, and Cal Poly San Luis Obispo, we have been able to help weigh nesting leatherback turtles!!  Our goal is to examine and score the body condition of the nesting females at this point in the nesting season as well as finding a baseline weight for this population.

The process is fairly intensive and involves all hands on deck!  Once the crew encounters a turtle, LMC staff collects our normal samples: blood, a skin biopsy, and measurements.   

Pre-weighing procedures as Director of Research Justin Perrault takes a blood sample, Heather Liwanag of Cal Poly SLO take IR images of the turtle, night tech Kate Fraser records various data info, and Heather Harris of Upwell performs an ultrasound on Panda. (Photo: Derek Aoki)

As we collect our samples, two to four people dig a trench under the turtle at approximately her CCW (curved carapace width), or the widest part of her body, and two straps are fed under her and secured with rope. Then we attach the rope to a spreader bar, which is attached to a scale, which is attached to a pulley, which is all connected to an 11 ft. carbon fiber tripod that we place over the turtle.

Once the turtle finishes laying, two straps are fed under the turtle and secured with rope as seen by Kate Fraser and Upwell members Dr. George Shillinger and Dr. Heather Harris. (Photo: Derek Aoki)
The secured ropes are attached to a spreader bar, which helps evenly distribute the weight of the turtle and ensure she is not tilting or off balance. (Photo: Derek Aoki)

Once she is starts to cover her egg chamber with her rear flippers, one person will use the pulley and lift the turtle off the ground, which in most cases, means digging under the turtle even more to ensure her massive front and rear flippers are not touching the sand. 

The spreader bar is then attached to the scale and once that is secured to the tripod, she is ready to be lifted and weighed! (Photo: Derek Aoki)
Phoenix as she is about to be lifted off the ground! (Photo: Derek Aoki)

After we get an accurate weight, we gently lower the turtle, remove all of the gear, re-group, and hop back on our ATVs to find another!     

Over the duration of this exciting research, Upwell and LMC were able to weight six individual turtles!! The heaviest leatherback was June Bug, who came in at an astonishing 412 kg (908 lbs.)!! This was also the second time we saw her this season. Sydney Tuttle was the lightest at 262.8 kg (579 lbs). The remaining four females that we weighed were Marilyn (275.6 kg/607 lbs.), Panda (303. 9 kg/670 lbs.), Phoenix (352.8 kg/777 lbs.), and Gisli (370 kg/815.71 lbs.).

And that’s a wrap on this week. Special thanks to Dr. George Shillinger and Dr. Heather Harris of Upwell for allowing LMC to assist in their leatherback body condition research, to Dr. Heather Liwanag of Cal Poly for loaning her tripod and scale, and to everyone else who lent a hand in this fascinating project.

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-19-205.