Student Research Projects

Swimming dynamics in loggerhead sea turtle (caretta caretta)

Student Kelly Jacobson ‘15 (Biology and Earth & Environmental Science)
Faculty Mentor(s)
Department Biology
Course Biology 489: Research in the Natural Sciences

Abstract

Sea turtle hatchlings and post-hatchlings employ multiple modes of swimming, including drag-based ‘dogpaddling’, drag-based ‘rear flipper kicking’, and lift-based foreflipper ‘powerstroking’ (Wyneken, 1988, 1997; Davenport and Clough, 1986; Davenport et al. 1984; Davenport and Pearson, 1994; Rivera et al., 2011). The utilization of these swimming patterns varies with ontogeny and species, with loggerhead (Caretta caretta) hatchlings and post-hatchlings exhibiting all three modes throughout their early life history stages (Wyneken, 1997). In addition to thrust production, the hind and foreflippers of loggerhead hatchlings may play an important role in maneuvering (Avens et al., 2003; Dougherty, 2009). While it is assumed that loggerhead sea turtles actively swim during their offshore migrations and subsequent pelagic life stages using the modes described above, it remains unclear how proficient they are as swimmers. This is, in part, because studies to date have not been performed in water tunnels, where the swimming speed of the turtle can be precisely controlled, using high-speed, multi-camera arrays, which can provide high resolution for detailed analysis. For this study, I used three high-speed cameras to videotape loggerhead sea turtle (Caretta caretta) yearlings swimming in a water tunnel, with the overall goal of assessing swimming performance in a quantitative manner. Specifically, my objectives were to: (1) determine the maximum sustained swimming speed and (2) measure body and appendage movements during active swimming with high spatial and temporal resolution to assess thrust and lift production. These data are important not only for understanding swimming performance of sea turtles during critical early life history stages, but also to provide a foundation for subsequent modeling studies that can help better understand how modifications to the animal (fouling by invertebrates, trauma to flippers, diseases, etc.) can impact swimming success and survival.

Grants

Recipient of a research grant from the Virginia Foundation for Independent Colleges (VFIC), summer 2014.