About This Project

Unlike hard-shelled sea turtles, the leatherback’s soft-shell changes shape relative to their nutritional condition and can be used as a visual indicator of their health. These gentle giants can weigh over 1000 lbs. when foraging, making them a challenge to study at sea. Aided with biotelemetry tags, our goal is to conduct the first study to validate drones as a new, noninvasive technique to analyze leatherback health by analyzing leatherback body condition on nesting and foraging grounds.

Ask the Scientists

What is the context of this research?

The population of northwestern Atlantic leatherbacks has decreased by 60% since 1990. Climate change may be primary driver of this decline, as warmer sea surface temperature could cause alterations to important food stocks. Nesting leatherbacks have to eat and store enough energy on foraging grounds to facilitate their migration, egg production, and survival between nesting events, and any changes in food availability and locations could affect their nutritional status as they reach nesting grounds. Therefore, there is a need to keep track of current foraging grounds of sea turtle populations, so researchers can assess the current state of their food stocks and understand how foraging and migration conditions influence their health once they arrive to nesting beaches.

What is the significance of this project?

This will be the first study to use aerial photography to estimate body condition on sea turtles. Drones have been used to assess sea turtle population size and location, mating behavior, and other morphological traits, but have not been used to evaluate body condition. Because leatherback body thickness fluctuates with nutritional condition, drone imagery could allow us to detect changes in body shape from their nesting grounds to foraging areas. By comparing measurements from aerial photographs to those taken by field researchers, we hope to create a novel, less invasive method to study leatherback body condition.

What are the goals of the project?

The goal of this project is to evaluate aerial photography as an appropriate method to measure leatherback body condition. The study will commence during the 2021 nesting season, where we will use a DJI Phantom 4 Pro drone to take aerial photos of nesting leatherbacks throughout the nesting season. These photos will be analyzed in ImageJ, and if successful, we will travel to foraging grounds and compare turtle body condition between these two habitats.

We will tag up to 20 turtles with satellite tags over the 2022–2023 nesting seasons to identify current foraging grounds. This will allow us to track individuals throughout their inter-nesting habitats and on their migration to foraging grounds and update the last report for this population, published in 2006.