Hear that whirring above your head while you’re at the beach? Doesn’t sound quite like a helicopter… but it’s a familiar whooshing sound. I promise you it’s not a lyrebird that’s learned a new trick – look up, it’s a drone!
Over the past decade, drones (the common term used for unmanned aerial vehicles – UAVs) have become a popular tool for wildlife management and research. As technology has rapidly evolved, along with increasing visualization capabilities and cost-effectiveness, observational studies have become trendy, particularly in the field of marine science. In addition to aerial monitoring from planes and helicopters, drones are a natural extension of this research technique.
Drones are increasingly being used in several marine science fields, such as animal monitoring, coral health analysis, and marine geomorphology, among others. They’re easy to deploy and recover, and can be used in polar, temperate, and tropical marine environments. Drones can repeat observations within a single day with their variety of sensors, thanks to batteries being easily changeable. I should know – I’m using them for my current PhD research in Western Australia where I’m doing transects to study shark behaviour in a remote, coastal lagoon.
“Drones [also] in general have very little effect on animal behaviour. This means we can observe natural behaviours that were previously difficult to see because they would require finding the interaction in question and then boating/swimming/diving to the area to observe it, which involves a lot of noise and big things in the water,” explains Dr. Vincent Raoult, a postdoctoral researcher at Macquarie and Deakin Universities, who has previously used drones in his research.
However some agencies, like the Queensland Department of Parks and Forests, have guidelines for use, to avoid disturbing animals, and in some places ban drones completely.
In 2016, the NSW government began trialling drones for shark-spotting, and Surf Life Saving NSW has done so since 2018. Queensland has also been considering this non-lethal alternative, successfully spotting the big predators at Alexandra Headland.
Not only are they useful for tracking and identifying sharks, this can be combined with alerting beachgoers to remove themselves from the water, as well as closing beaches to reduce the risk of attacks. Helicopters passing over beaches on the lookout for sharks may soon be a thing of the past.
In a survey conducted in 2020, the public overwhelmingly say drones are preferable for protecting beachgoers from shark attacks. “Historically beach patrols from helicopter were common, but studies have shown they weren’t too effective at spotting sharks, and they were obviously very expensive to run,” Raoult says.
“In Australia, most busy beaches now have regular drone patrols for this purpose, with the added bonus that those drones are also very useful to find swimmers in distress or other risks to beach users, so using drones to ‘spot sharks’ is a clear win to me.
“The proliferation of drones on our coastlines has shown us that completely harmless shark/human interactions are likely to be much more common than we thought. How many videos are produced each week showing large ‘dangerous’ sharks swimming within meters of oblivious swimmers? Over time, I hope that this imagery will really change the attitudes towards sharks on our beaches.”
Drones can change attitudes and also bring us new insights that traditional research has missed. For example, drones have shown us white sharks, which regularly patrol along long beaches, generally do so only in one direction before moving to other areas.
But collecting robust data on large marine animals is expensive, so sharks aren’t the only big animals that marine scientists are studying using drones.
“A recent study from New Zealand used drones to spot manta rays so that a boat could then find them and tag them much more efficiently than before,” says Raoult, who also says some drones take specific measurements (for example, ‘weighing’ baleen whales and assessing their health), and the flight data they collect can be used in a similar fashion to satellite/acoustic tags, but without the distress that tagging can produce.
A new citizen science whale monitoring program off the coast of NSW is also using drones to monitor, track and ID southern right whales (Eubalaena australis).
Elsewhere, scientists from the Royal Netherlands Institute for Sea Research and Wageningen Marine Research, hope to use drones to study harp seals (Pagophilus groenlandicus) in the Arctic, use thermal drones to detect and observe sea turtles, detect pregnant dolphins, and for examining penguins in Antarctica. And while drones are usually used for non-invasive methods, Ocean Alliance recently became the first team to tag whales using a modified DJI drone to drop suction cup tags onto blue (Balaenoptera musculus) and fin whales (Balaenoptera physalus).
But there are limitations to this technology. “One is their flight time, though that has improved dramatically over the last decade (from about 15 minutes of useable flight time to more than double that).
Another is that they can only see into the water if the conditions are good. In perfect conditions, that means seeing to about 10 meters, but most of the time drones can only see what’s in the first two or three meters of the water column,” says Raoult.
“There are some uncertainties about how drones affect behaviours, some species (like seabirds) can react very negatively to the presence of drones, while others (like sharks) presumably don’t care much.
“This is something that needs to be explored further, but we can limit those impacts with the precautionary principle – generally meaning flying further away from the animals, but thankfully zoom lenses on drones are becoming more common!”
Still, the benefits outweigh the costs of using drones. With continued advances in the drone field, this technology promises to complement conventional scientific methods to studying our oceans. “I really see drones as being a necessary tool that marine scientists take on their fieldwork in the future. It’ll be viewed in the same way as quadrats and transect lines: something you take with you whenever you go in the field because it’ll likely be handy at some point.
“What I’d like to see is the strengths of drones work hand in hand with other cutting-edge techniques like tagging, to really build some comprehensive views on the lives of marine creatures.”
If you are in Australia and keen to take to the skies The Victorian Department of Environment, Land, Water & Planning has funded citizen science drones to survey the state’s coastline to provide critical information for determining the dynamism of beaches.
Sixteen sites have been established across Victoria from Portland to Seaspray involving more than 100 community members and 25 council & state government employees. Over a year’s worth of data has already been collected at most sites!
Do you care about the oceans? Are you interested in scientific developments that affect them? Then our new email newsletter Ultramarine, launching soon, is for you. Click here to become an inaugural subscriber.
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