Learning from sea turtle piggy-backers

Targeted conservation efforts depend heavily on collecting geographical location data from turtles. Traditionally, tracking has been achieved by tagging, but promising new research into isotope analysis may allow researchers to take advantage of turtles’ built in tags—epibiont barnacles. This new technique is being utilized to help shed light on turtles’ habitat use and  distribution patterns. So, what do barnacles have to do with sea turtle tracking? 

Epibionts, the marine invertebrates that attach or rise on sea turtles are essentially just turtle hitchhikers. The majority of epibionts are barnacles which attach to and grow on the turtles’ body, and each turtle has its own unique makeup of epibionts that may reflect where the turtle has been feeding. Most sea turtle biologists remove barnacles and throw them away, while Upwell researchers and partners find that they can serve as keystone species in the sea turtle epifauna, sea turtles serve as a microecosystem.

These tiny animals act as mini data-loggers and can provide information about where the turtle has traveled recently, thereby increasing our understanding of their habitat use. There are over 50 species of epibionts documented that use sea turtles as their habitat but Upwell’s research focuses on one barnacle species Chelonibia testudinaria, that is only found on sea turtles. Currently, our research in northwest Mexico is focused on a combination between carbon and nitrogen stable isotopes, which have a reliable distribution in otherwise highly dynamic ocean ecosystems. 

This summer, Upwell volunteers Kajsa Williams and Vanessa Pelayo processed 710 barnacles by cleaning, measuring, photographing, and extracting material for stable isotope analysis in the Centro Interdisciplinario de Ciencias Marinas (CICIMAR) lab in La Paz, Baja California Sur. Soon, Upwell and our partner Grupo Tortuguero de Las Californias A.C. will be publishing a barnacle protocol for sea turtle research centers in Pacfic Mexico with the aim of reaching 5,000 barnacle measurements for our online database. As this is a novel field of inquiry and little is known about the growth patterns  of these epibionts, our collaborative project also aims to establish biometric baselines so that researchers can determine not only where the sea turtle has been in the ocean, but with biometrics, we can place a timing on that location.In Kajsa’s own words, 

“The heart of the 5,000 barnacle project is necessarily citizen science. While I believe that this experience has both benefited me personally by exposing me to much needed scientific experience, it has also benefited the project as a whole by providing a substantial foundation for the analysis of biometric data from all 5,000 barnacles. Thank you to Upwell biologist Stephanie Rousso and Grupo Tortuguero for inviting me into the field. Reflecting now on my time in La Paz, I realize what a quantity of work we accomplished.”

Kajsa Williams in the lab at CICIMAR. Photo: Stephanie Rousso

Kajsa Williams in the lab at CICIMAR. Photo: Stephanie Rousso

Upwell scientists in Mexico are asking sea turtle biologists throughout the Pacific Mexico region to save the barnacles they remove from sea turtles and help collect vital measurements that will contribute to better understanding the stable isotope findings. Upwell will also be presenting a poster at the 2nd International Conference for the Conservation of Eastern Pacific Sea Turtles to generate interest from biologists who are currently permitted to work with sea turtles in Mexico to help collect data on barnacles.