The team learned about the turtle's habitat needs during the nesting season by using ATRIS, a georeferenced, underwater camera system developed by the USGS to collect over 195,000 seafloor images. Researchers surveyed the areas frequented by turtles within Dry Tortugas National Park by photographing the seafloor in a series of parallel lines totaling 70 kilometers (over 43 miles). Using a habitat map derived from those images, they found that the turtles most commonly used shallow seagrass beds and degraded coral reefs that have been overgrown by a mixed assemblage of other organisms, such as sea fans, sponges, and fire coral.
"Our synergistic approach of combining satellite telemetry data with an extensive habitat map proved to be an effective way to find out exactly what habitats these nesting turtles were using in the Park," said Dave Zawada, a USGS research oceanographer and co-author on the study.
The Dry Tortugas' population made shorter migrations than that typically seen among other green turtle populations around the world; this was only the second published study showing green turtles taking up residence at feeding grounds located quite near their breeding grounds.
"We hope to keep pushing the frontier of what is known about in-water sea turtle habitat use, as this type of scientific information is vital for understanding whether conservation measures are effective," said Hart.
The study, "Habitat use of breeding green turtles Chelonia mydas tagged in Dry Tortugas National Park: Making use of local and regional MPAs," was publish
|Contact: Kristin Hart|
United States Geological Survey