For instance, conducting focal animal behavioral follows on dolphins using drones allows us to detect fine-scale movements and responses to events with a higher level of detail and accuracy compared to vessel-based observations. In combination with boat-based observations, acoustic recordings, and data from hydrophones or digital acoustic archival tags (DTAGs), the approach can be even more powerful.
We have implemented drone use in our collaborative Strategic Environmental Research and Development Program project entitled “Towards
an Understanding of the Cumulative Effects of Multiple Stressors on Marine Mammals — an Interdisciplinary Working Group with Case Studies.” Although the turbid waters of Barataria Bay, Louisiana, make it challenging to view animals from above, we are still able to use this technology to observe their behavioral responses to approaching vessels.
In May 2022, we were joined by Fabien Vivier, studying under Lars Bejder at the University of Hawaii, to investigate the health and pregnancy status of individual dolphins through drone photogrammetry. This involved launching the drone from a boat and flying directly over top (at a safe and federally permitted altitude) to record video of the animals surfacing. Post-field work, the videos are analyzed and lengths can be determined via mathematical formulas. In Sarasota Bay, calibration of this technique is possible because of measurements obtained during health assessments. The results obtained will allow us to inform management agencies and implement conservation strategies on these populations more rapidly.
—Jonathan Crossman, SDRP Staff Researcher