Drones for Marine Mammal Research
Marine mammals are inherently cryptic species; they spend most of their time underwater and have very wide geographic distributions, making it difficult to study these animals up close. Recent advancements in the technology of remotely piloted aircraft systems (RPAS, more commonly known as "drones") have allowed for unique opportunities to study marine mammals at sea. The aerial perspective allows researchers to obtain stable, full-body, high-resolution imagery of animals. Still photographs can be used to measure body parts (called photogrammetry), assess health (by quantifying parasite loads or evaluating body condition), and investigate human impacts (by looking for entanglements, injuries or scars). Videos are also being used to analyze the behavior and social interactions of marine mammals.
For Gina’s PhD research, she’s using a drone to measure whale body condition and body temperature. A high-resolution drone camera allows her to obtain precise ratios of body length to body width, which serve as proxies for body condition. A drone thermal sensor can remotely measure heat that radiates from a whale’s body and blowholes when it is at the surface. By looking for individual, temporal, and geographic differences in these metrics, Gina hopes to identify healthy versus compromised whales and establish baselines for future health monitoring.
There are many advantages to using drones rather than traditional boat-based or manned aircraft approaches to studying marine mammals. First, as drones become more popular, they are becoming less expensive, and the technology is becoming more user-friendly. Flights require fewer personnel, with some operations only needing one pilot and a visual observer. Second, drones can get closer to marine mammals without the risks involved with putting people in airplanes or approaching animals by boat. Still, some worry that conducting drone operations around marine animals is exposing them to more human disturbance, due to the unfamiliar sight and sound of the drone in the air. Therefore, it is important to monitor animal behavior when conducting drone research. As a side project, Gina is measuring the amount of sound produced by the lab’s DJI Matrice drone when flown at different altitudes and speeds. She will measure the sound using a microphone on land as well as a hydrophone underwater. This way, she can evaluate whether right whales will be able to hear the drone during research operations. Based on the results, she will adjust her flight logistics to minimize the potential of disturbing whales.