Continuous wildlife monitoring using blimps as an aerial platform: a case study observing marine megafauna

Abstract

Aerial surveys are a powerful means of collecting ecological data in terrestrial and marine systems that may otherwise be difficult to acquire. Increasingly aerial observations are made with Unmanned Aerial Vehicles (UAVs), such as drones. As this technology has improved in reliability and affordability it has replaced the traditional use of fixed-wing aircraft and helicopters. Drones do, however, have limitations; primarily in their limited flight duration, potential to disturb wildlife and concerns over safety. Here we introduce an aerostat, a ground tethered blimp, as a logistically simple and economical alternative to drones and other aircraft. Blimps differ from drones by using helium for lift, thereby conserving battery life. This technology offers the advantage of near-continuous coverage of locations, as well as providing a safe and accessible alternative aerial platform for a range of applications. We demonstrate the viability of blimp-mounted cameras in a notoriously difficult area to conduct research: the high-energy nearshore marine zone. Specifically, we sought to determine the likelihood of encountering marine megafauna using real-time video and whether their presence was correlated with the occurrence of baitfish. Stingrays were observed more often than other species and the occurrence of seals was correlated with the presence of baitfish. The continuous coverage allowed the observation of foraging behaviour in sharks and seals for extended periods. This demonstrates the utility of this novel technique to improve human safety and enhance ecological research.

Determining Stingray Movement Patterns in a Wave-Swept Coastal Zone Using a Blimp for Continuous Aerial Video Surveillance

“…Aerial video surveillance is an emerging technique with great potential to provide behavioural information in high-energy coastal zones [23,27]. Unlike tagging methods, this non-invasive technique gathers continuous and direct information about animal locations and interactions [28,29].…”

“…Unlike tagging methods, this non-invasive technique gathers continuous and direct information about animal locations and interactions [28,29]. Moreover, aerial video surveillance is relatively cost-effective given that, besides scientific staff, it only requires a platform to keep a camera suspended in the air [27]. Despite the potential environmental limitations related to light, wind, and water clarity conditions, this technique can provide access to areas where other tracking methods are unsuitable, even when they are remote or dangerous to access [27,28].…”

“…Moreover, aerial video surveillance is relatively cost-effective given that, besides scientific staff, it only requires a platform to keep a camera suspended in the air [27]. Despite the potential environmental limitations related to light, wind, and water clarity conditions, this technique can provide access to areas where other tracking methods are unsuitable, even when they are remote or dangerous to access [27,28]. The use of this technique for gathering information on megafaunal habitat usage and spatial ecology in coastal zones promises to contribute significantly to improving the understanding and management of these ecosystems [29][30][31].…”

“…Furthermore, researchers need to simultaneously operate the drone and monitor the field of view, which requires experience and can induce fatigue [34]. Aerostats (balloons or blimps) may constitute a more suitable aerial platform for particular cases by overcoming some of the limitations of drones [27]. Aerostats differ from drones by using helium for lift, offering a near-continuous coverage of study areas since they are only limited by the battery of the camera, which can exceed 8 h. In addition, they are silent, reducing potential impacts on wildlife [27].…”

“…Aerostats (balloons or blimps) may constitute a more suitable aerial platform for particular cases by overcoming some of the limitations of drones [27]. Aerostats differ from drones by using helium for lift, offering a near-continuous coverage of study areas since they are only limited by the battery of the camera, which can exceed 8 h. In addition, they are silent, reducing potential impacts on wildlife [27]. Aerostats have been used for monitoring the occurrence of marine wildlife, including whales [35]; dugongs [36]; sharks [37]; and, complimentarily to the present study, seals, sharks, and stingrays [27], although no movement patterns have been analysed.…”