Tuesday June 18, 2024
NOAA Fisheries —
Drones not only take great photographs—they can also be used to take measurements. In our case, we use them to measure the size of sea turtles seen in the wild.
Photogrammetry is the process of getting reliable measurements from photographs. This technique has been used for more than 100 years, primarily to create maps from aerial photos. With advanced drone technology, biologists are using photogrammetry to measure sea turtle species like leatherbacks, loggerheads, and Kemp’s ridleys.
Collecting size information using photogrammetry helps us understand what age groups of different sea turtle species are using which areas, and when. For example, scientists from NOAA’s Southeast Fisheries Science Center recently used this method to measure juvenile green sea turtles in coastal Louisiana. At another site in North Carolina, we saw and measured adult and juvenile loggerhead sea turtles. This might suggest that different species of turtles occur within different regions. Collecting information on size and habitat use informs conservation management strategies and helps assess progress toward recovery. Another benefit: measurements can be made without having to capture and handle the turtles. This means more animals can be measured in a day and the turtles don’t even know we’re there.