January 20, 2021

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Bay Watch / Using drones to monitor box jellyfish on our beaches

3 min read
With stinger nets back in place on our local beaches, attention turns once again to the "stinger season". In a promising development, researchers from James Cook University in Cairns have demonstrated, for the first time, the potential for off-the-shelf drones to be used to detect these deadly box jellyfish.

JAMES COOK UNIVERSITY


With stinger nets back in place on our local beaches, attention turns once again to the impacts of “stinger season”. In a promising development, researchers from James Cook University in Cairns have demonstrated, for the first time, the potential for off-the-shelf drones to be used to detect these deadly box jellyfish.

The research, published this week in the journal PLOS One, focused on Chironex fleckeri – a large jellyfish capable of killing a human in under three minutes and considered the most venomous animal in the world.

Chironex fleckeri, the Australian box jellyfish, Image credit Science Mag

Chironex fleckeri is found in waters off northern Australia from October to May, when its liking for shallow, calm, coastal waters can put it on a collision course with swimmers,” said PhD candidate and project lead Olivia Rowley.

“Drone surveillance could help make our beaches safer, and reduce our reliance on time-consuming drag netting by life savers.”

JCU PhD candidate and project lead Olivia Rowley

Ms Rowley and colleagues from the Australian Institute of Tropical Health and Medicine set out to establish the reliability of lower-cost consumer-grade unmanned aerial vehicle (UAVs or drones) in detecting these large, near-transparent and logistically difficult jellyfish.

“The attraction of these devices is that they are more affordable, easily transported, and easier to use,” Ms Rowley said.

“They don’t require as much training and licensing as the higher-end versions and a large number of surf lifesaving clubs, particularly in Australia, already have them in their kit for rip identification, and crocodile and shark spotting.”

The researchers tested the drones’ accuracy as jellyfish spotters in waters near Weipa on Cape York Peninsula. They deployed 70-metre nets, and then recorded drone footage before pulling in the nets and counting and measuring any jellyfish.

During the experiment the drone pilot kept records of jellyfish spotted during each flight.  These records were later compared with the netted numbers, and with the accuracy achieved in a lab-based review of the footage.

The researchers confirmed that reviewing footage after the flights led to significantly high detection rates. They also quantified the effects of weather conditions such as cloud cover and wind on the drones’ success rate.

“This has huge implications. Most, if not all, beaches worldwide, from Japan to Europe and beyond, have issues with very harmful jellyfish and presently there is no way of telling if animals are there until someone gets stung,” Ms Rowley said.

Drones have the capacity to be used as an early warning system, and are fast, effective and cheap, helping to keep those on the frontline out of the water, and out of harm’s way.”

“Jellyfish are gaining increased attention worldwide due to the devastating effects of blooms on local ecosystems and, for some species, medical and economic implications due to their painful and potentially fatal stings. In areas around the world dramatic increases in the number and density of scyphozoan species has resulted in fishery collapses and caused significant losses to aquaculture stocks…

Cubozoans, a family of box shaped cnidarians which often occur in less dense aggregations but are known for their highly venomous sting, have caused millions of dollars in lost tourist revenue in several different geographical locations such as Waikiki beach Hawaii, Queensland Australia and the Mediterranean coast…however, despite these implications, there is a lack of data on distribution, density and spatial and temporal patterns for these marine invertebrates.

This absence has been directly related to problems with sampling and monitoring, as these organisms are not only difficult to visually detect but their physical nature make them inherently problematic to sample…”

STUDY RESULTS published in PLOS ONE Journal

The next stage of the project will see this research trialled with Surf Life Saving hubs along the Queensland coast. The trials are funded by the Australian Lions Foundation and will begin within the next month.

Full Report

Plos Journal / Bay Watch, Using unmanned aerial vehicles (UAV’s) to survey the box jellyfish Chironex fleckeri

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