Researchers from the Auckland University of Technology have found the safest distance to fly drones over marine mammals.
AUT conservation biologist, Associate Professor Barbara Bollard, and Master of Science student Ticiana Fetterman wanted to understand whether marine wildlife is stressed or disrupted by drone use.
In consultation with the Department of Conservation, they researched a pod of bottlenose dolphins off Great Barrier Island, in Auckland’s Hauraki Gulf.
Fetterman conducted boat-based surveys to assess short-term responses of resting bottlenose dolphins to a lightweight vertical take-off and landing UAV flown at altitudes of 10, 25 and 40 metres.
Changes to the group’s swimming direction and frequencies of above-water activity, including jumping out of the water, were recorded from an anchored research vessel before (as a control) and during the use of the UAV.
Dr Bollard says, when dolphins are stressed, they slap their tails, chin slap the water and the pod changes direction to avoid the drone. Recordings of this behaviour increased significantly when the UAV was flown at 10 metres over the animals.
The behaviour was reduced in a buffer zone of 10 to 25 metres and there was no significant detection with the aircraft at 25 metres and above.
The findings have been published in the journal Scientific Reports and will be used by marine researchers worldwide.
Dr Bollard says although the study was on dolphins, the findings inform best practice for all marine mammals.