All dolphins in Australian waters are protected species. While some dolphins found in Australia are relatively common elsewhere, others, such as the snubfin and humpback dolphins, are unique to Australia and vulnerable to extinction due to their low numbers and slow population growth.
Until recently, the information about the two native species of dolphins found off the northern coasts of Australia was scarce. But that is changing with scientists now gathering more information than ever before - thanks to the drones.
"The use of drones in marine mammal work is really at the beginning of its journey," says Dr Daniele Cagnazzi, a conservation biologist at the Marine Ecology Research Centre of Southern Cross University in NSW.
"So far drones have been mostly used for bigger animals that are easier to observe and less mobile than dolphins, like the humpback whales. We are using the same techniques on dolphins for the first time."
With the use of drones, researches are observing the dolphins more closely and can monitor their general well-being.
Daniele Cagnazzi and his team researching on the snubfin dolphins and the humpback dolphin in Queensland Source: Courtesy of Daniele Cagnazzi
"We basically fly the drone over the dolphins to estimate dimensions and bodily characteristics, their population dynamics and their unique behaviours."
However, close observation of this highly intelligent marine mammal by the drones revealed some of their interesting behaviours to the scientists for the first time.
"We were able to observe the snubfin dolphin's hunting technique: it spits the water out of the mouth to attract the fish to the surface. Before this, we could not see its prey, so we had no record of this specific behaviour," Dr Cagnazzi told SBS Italian.
Interaction with birds and dangerous feeding behaviour
He says the studies by drones also revealed an interesting interaction between the dolphins and birds.
"A snubfin dolphin killed a little fish with its flukes and turned around to grab the fish with the mouth, but a bird flying in the sky dives down to steal that fish from the dolphin."
He says the dolphin anticipating the bird's attempt to steal the prey was a "good" interaction to observe.
A Humpback dolphin and calf in Darwin Harbour. :By Carol Palmer Source: AAP
Before this, Dr Cagnazzi was able to identify "dangerous" feeding behaviour in humpback dolphins, known as 'strand feeding', in the Fitzroy River in Queensland.
“Strand feeding occurs where dolphins patrol the mud banks in search of prey; once the prey has been localised a dolphin swims at high speed toward the shore, catches the fish in its mouth and remains stranded for a short time before sliding gently back into the water,” he says.
This is risky because the dolphin can remain stranded in the mud.
Dolphins need up to six per cent of their body weight in fish every day. Dr Cagnazzi says strand feeding seems to provide dolphins important proportion of their daily food, as it's repeated routinely.
He says these behaviours weren't known to researchers before because they were observing the dolphins from the sea level.
Dr Cagnazzi will continue collecting new data off the coast of Yeppoon, in central Queensland, for a few more months in the hope it can contribute to the conservation of the native dolphins because he says "knowledge is the key for conservation."
He says the use of drones is limited to areas close to the coast currently, but he hopes researchers will be able to fly them to remote locations soon.
"I hope we will be able to use drones to explore some areas, especially the north side of the Great Barrier Reef and northern Queensland, where there is very little information and assessing the water can be very difficult and there is virtually no information on the threatened species. The drone can provide a new platform to collect data for the inshore areas."
Both the snubfin and humpback are coastal dolphins. Dr Cagnazzi says it is important to monitor the conditions of areas close to the habitat of these dolphins because everything that happens on the coast impacts the survival of these species.
The biggest threat to dolphins is from plastic pollution, industrial development on the coast, shark nets and commercial fishing nets.
"They are involved in boat accidents, can get entangled in nets, but also coastal building development that takes away their natural habitat is a problem. Their survival is linked to the quality of the environment and the availability of food. So if the coast is ruined, dolphins will also be affected."
Effects of the drone on dolphins
A part of Dr Cagnazzi's research is also to study the effects of drones on these dolphins.
"Dolphin is a very social animal, they use sound to communicate between them - to look for prey, to hunt. So, their behaviour can be affected by underwater sound, especially if it is from anthropogenic sources. We don't know yet to which point the noise emitted by the drone can affect dolphin behaviour.
"It's something we want to understand, not just to minimise the effect of the drone on dolphins but also to minimise its effect on the data that we collect."
Dr Cagnazzi also works with government agencies, such as the Great Barrier Reef Marine Park and the Queensland Parks and Wildlife Service, to promote awareness about conservation of endangered species.
Their survival is linked to the quality of the environment and the availability of food, so if the coast is ruined, dolphins will also be affected
"Many people are using drones for recreational purposes today, but not everyone knows that whales and dolphins in Australia are federally and state protected. If you see a whale and you have a drone, you can't just fly over the animal to take pictures; you have to keep a certain distance, you have to approach the animal from a certain angle, and it depends on whether the animal is accompanied by a baby."
A good place to start understand how to help protect whales and dolphins a is the Great Barrier Reef Marine Park Authority which lists the basic rules for whale and dolphin observation. These rules may vary in different states and territories.
