Sea Turtle Research Projects
Centuries of exploitation have depleted sea turtle populations to a fraction of their historical numbers. Successful conservation depends on protection of these endangered species, their habitat and predators – all of which vary greatly among coastal communities. The continued decline of sharks, sea turtles’ natural predators, and human driven changes in habitat can affect turtle behavior and habitat use. The Heithaus Lab has been involved in sea turtle research since 1997 when initial studies began as part of the Shark Bay Ecosystem Research Project (SBERP) in Western Australia. Studies have since expanded to several locations including the Caribbean Sea (French West Indies and Abaco, Bahamas), French Polynesia, and Madagascar. Using a combination of observational and experimental studies, we investigate the role of predation risk from large sharks in shaping sea turtle behavior; the effects of environmental factors on diving behavior, foraging ecology, and individual specialization in behavior; and the role of sea turtles in seagrass and coral reef ecosystems.
The lab continues to employ and improve technology to study sea turtles. In 1999 we first used Animal-Borne Video and Environmental Data Collection (AVED) systems with the deployment of National Geographic’s Crittercam on both green and loggerhead turtles. Now several types of custom-built systems are used, featuring cameras (now primarily GoPro®) and tags to gather detailed data on turtle diving, foraging, and social behavior. We conduct abundance and density surveys by boat, on snorkel and unmanned aerial video (UAV), using DJI Phantom quadcopter drones. Through international and multi-institutional collaborations, we also incorporate data, from Global FinPrint and longer-term monitoring programs of turtle distributions, into our studies.
Hawkbill Sea Turtles
Hawksbills (Eretmochelys imbricata) are understudied relative to other species. Known to be predominantly sponge eaters, they spend their adult life on coral reefs. Previous research indicates that hawksbills have the potential to play a vital role in shaping marine ecosystems despite their small population numbers; however, the effects of turtle foraging on community dynamics between prey and habitat remain largely unclear. The goal is to develop a better understanding of how habitat quality affects hawksbill sea turtles and what role these turtles play in coral reef ecosystems. We are conducting research on hawksbill foraging in Nosy Be, Madagascar using Animal-Borne Video and Environmental Data Collection (AVED) Systems, tow diver surveys, stable isotopes and exclosure cages; and we are analyzing data collected in French Polynesia and from Global Finprint.
Green Sea Turtles
Many regions are implementing sea turtle and even shark protection, but many marine ecosystems within these regions are strongly affected by human generated stressors. In Abaco, Bahamas, the lab has a rare opportunity to study the non-human factors affecting a recently protected green turtle population so that management agencies can apply ecologically meaningful conservation tactics. Using unmanned aerial video (UAV), baited remote underwater video (BRUV), and seagrass surveys the lab studies green turtle foraging ecology including how food availability, food nutritional quality and predation risk affect turtle habitat use and the impact of turtle grazing on seagrass communities. In 2014, the Heithaus Lab expanded their study of Caribbean sea turtles to Guadeloupe, Martinique and St. Martin. More >>