Bio 125/Env 227L, Biology and Conservation of Sea Turtles


The hot many sea turtles ever make it to the sea. The ones that do are con-sidered delicacies by the greater oceanic world and are mostly eaten up in a gulp or a chomp. The few that do make it, though, become loggerheads or leatherbacks or one of seven other species of large, colorfully encased creatures passionately researched, observed, and protected by a man named Larry Crowder.

To his students at the Duke Marine Laboratory in Beaufort, North Carolina, Crowder, who has spent the last twenty years assessing sea turtles’ endangered state and the last four teaching the course, likens his work to, of all things, selling insurance. “Population modeling was first invented by insurance men in Babylonia. They would take your information and calculate whether you would die by forty or fifty or sixty in order to figure out how much to charge you,” he says. “We’re just working with turtles. ‘How do they survive? How many eggs do they lay? How old are they? Do they smoke?’ And we use mathematical techniques to determine whether the population is likely to increase or decrease.”

Crowder’s cross-listed course is designed around the premise that, in order to protect the turtle, one must know the turtle—in totality. First lectures cover sea-turtle anatomy, physiology, and phylogeny; diving adaptations; and habitat destruction before moving on to the technologies used in the field, effective conservation strategies, and analyses of the law and policy in place. In the spirit of the Marine Lab’s goal of experiential learning, students conduct necropsies on washed up carcasses, take boat trips to observe live sea turtles, visit a sea-turtle hospital, and aid in the research of lab-raised hatchlings. “This is a very hands-on course. We like to give students access to the critters and, since we have a good cooperative relationship with the State Department of Environmental Conservation, we can.”


Larry Crowder, the Stephen Toth Professor of marine biology in the Nicholas School of the Environment and Earth Sciences, specializes in conduct models and statistical analyses to assist in endangered-species management for both aquatic and terrestrial species (He also studies red-cockaded woodpeckers.) The bulk of his work has been devoted to developing programs in marine conservation. For instance, he was among the scientists who conducted research on the “turtle-excluder device” used by trawling fishermen to keep Kemp’s ridley sea turtles out of their nets. After his group’s findings showed the device was the single factor that most aided Kemp’s ridley populations, the number of that species rose from 300 in 1996 to more than 6,000 today.


The course includes lecture, discussions, lab work, and field trips—occasionally at night. Students take two quizzes, write one paper based on library research, and submit a final presentation based on the paper.


The Biology of Sea Turtles, edited by P.A. Lutz and J.A. Musick.

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