Abstract
Quantifying the health of marine mammals is an important task in understanding how these animals behave and react to anthropogenic stimuli.1 It is possible that by examining the hormone cortisol, the relative stress level of small cetaceans can be discerned.2 This hormone can be analysed from examination of the breath and/or mucus of the mammal. It is known that the mucus found in the flow generated from dolphins’ blowholes can be tested for hormones that help understand the current health status of the dolphin. Recently, attempts have been made to capture this hormone in the breath of both whales and dolphins with multi-rotor uncrewed air systems (UAS) by flying through the “blow” of the mammal as it breaks the water surface to breathe.3
As UAS use increases in popularity and utility as a tool for monitoring and studying cetaceans a number of limitations have come to light with respect to current platforms.4 This includes but is not limited to harassment risk and behavioural alteration of subjects. These concerns are magnified when considering the challenge of obtaining blow samples with rotary UAS. Further complicating matters is the likelihood that these devices may deflect analyzable materials because of wind shear. There has been some success with whales as they are large, slow, with their expelled breath extending many feet into the air. Small cetaceans, on the other hand, have a much smaller expelled jet that doesn’t travel as far from the water surface. Yet, the emitted jets from dolphin blowholes have not been well characterized. In order to understand these jets, so that adequate samples may be obtained by UAS without alerting the population, a combined program of in situ measurements, experimental setups, and computational simulations has been designed. The current effort focuses on developing the capability to autonomously track a small cetacean specimen in the wild and capture samples using a UAS. This is demonstrated through surrogates that simulate the motion and exhalation of a dolphin allowing for a developmental program to test new UAS development. In our in situ efforts we will present data suggesting that the noise from standard multi-rotor UAS causes these animals to dive and elude the UAS preventing capture of breath.
We announce the development of a first of its kind UAS platform designed to mitigate the limitations of UAS platforms in the study of small cetacean health, through the use of acoustic and visual stealth advancements specifically built around the sensory capabilities and blow physics of small-toothed whales. We will highlight device development, capability, advantages and operation along with blow-field modelling and high-speed particle image velocimetry data granting a better estimation of successful blow collections. We will also preview new imagining technology and the implications for AI guided flight and approach.
Acknowledgements
We appreciate the assistance of Dolphin Quest facilities and staff in Bermuda, Oahu and Hawaii.
Literature Cited
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