Grant: 23-037R
Project Title: Swimming kinematics to understand neonate sea turtle dispersal
Project Manager: Jeanette Wyneken
Organization: Florida Atlantic University (Research and Educational Institute)
Grant Amount: $14,859.32
Completion Date: 2024-05-16
Summary: Swimming behavior switches occurs with habitat and life stage. However, the predominate swimming gait that is used throughout life for covering distances effectively and efficiently is the powerstroke. The life stages between when sea turtles first enter the ocean as hatchlings and when they return to coastal waters as benthic juveniles or nesting beaches as adults is particularly data deficient regarding offshore swimming. Yet, tracking literature suggests that although ocean currents play a major role in hatchling and neonate dispersal, passive drifting alone does not explain where these very young turtles end up. Investigation of the fine-scale swimming mechanics of neonates will improve the understanding of movement and behavior at sea by these "lost years" turtles. The objectives of this study are to (1) quantify several key parameters of swimming kinematics in neonate leatherback (Dermochelys coriacea), loggerhead (Caretta caretta), and green (Chelonia mydas) sea turtles, (2) improve the understanding of movement behavior at sea, and (3) refine our understanding of the dispersal of turtles at sea in and out of currents. The results of this study will be used to refine our understanding of tracking data by providing fundamental understanding of how powerstroking is similar or divergent and what these three species achieve with their routine swimming behavior.
Results: We have purchased the ADInstruments Teaching Force Transducer (0-50g), the ADInstruments Teaching Force Transducer (0-500g), and the PowerLab 2/26 with LabChart Pro. With this equipment, we have completed the collection of high-speed video on 36 leatherback, 21 loggerhead, and 32 green turtles as both frenzying hatchlings and pelagic-stage neonates. This brings our numbers to 89 of the proposed 108 turtles for this project. Sub-second thrust measurements have been collected in concert with the high-speed video for all frenzy and pelagic swimming trials to date (178 trials). These measurements were made possible with force transducers and PowerLabTM system acquired with these grant funds. All turtles from the 2023 nesting season have been recorded (with video and force measurements) swimming as both hatchlings and neonates as of January 31, 2024. Each species appears to exhibit a distinct pattern of force production over time.