Scientist have revealed that they have a long history of trying to use animals as spies, weapons and warning systems, but the latest plans to use marine organisms as motion sensors may be the strangest yet.
When a beluga whale was spotted wearing a harness recently, some speculated that it had been trained to spy for the Russian army.
That’s not as far-fetched as it sounds. Ever since the 1960s, the US Navy has been training dolphins to detect mines and help rescue lost naval swimmers. Russia’s been known to do the same.
And sharks, rats and pigeons have been enlisted over the years as eavesdropping devices, with mixed results.
The latest project from the US Defense Advanced Research Projects Agency (Darpa) aims to improve military intelligence by using a range of aquatic creatures – from large fish to humble single-celled organisms – as underwater warning systems.
“We’re trying to understand what these organisms can tell us about the presence and movements of all kinds of underwater vehicles in the ocean,” says Dr Lori Adornato, programme manager of the Persistent Aquatic Living Sensors (Pals) project.
Living creatures react in various ways to the presence of vehicles. One of the most familiar is the phenomenon of bioluminescence – some marine organisms glow with light when disturbed. This is the focus of one of Darpa’s strands of research.
“If you have an organism like noctiluca present on the surface of the ocean and an underwater vehicle that’s close to the surface, you will be able to see that from the air because of the bioluminescent trail,” explains Dr Adornato.
But the Darpa team is hoping to gain a far more detailed picture of the movements of submarines and underwater drones.
“We’ll be using advanced processing techniques, including machine learning, to analyze the signals and identify distinguishing features.”
The teams are looking at a range of creatures and behaviors. Goliath groupers, for example – which can grow up to 2.5m in length – are known to make a booming sound when approached by divers and also show curiosity when a new object enters their habitat.
These elements of the project involve monitoring what’s known as the soundscape, explains Alison Laferriere of project partner Raytheon BBN Technologies. Many species of fish constantly make sound to communicate or in response to external threats.
“If a vehicle comes in to their environment, the thought is that they might change their behavior in some way that we might be able to detect,” she says.
Behavior is an important indicator that potential sub-sea interlopers may be around. Why bother using a lot of energy to detect underwater vehicles when you could get a colony of shrimp to do it for you?
But are these projects really feasible or merely the fevered imaginings of grant-seeking researchers?
“There is a global push to work with animals for remote sensing,” says Dr Thomas Cameron, lecturer at Essex University’s biological sciences school, “both in the case of free living animals or in farming and aquaculture.
“Harnessing the behavior of animals to give us signals about the environment around us is not new to humans – we have done this with canaries in the mine and with our domestic dogs.
“What is unique in this program is the focus on wild free living organisms and the push to see what we can learn about signaling in the marine environment by focusing on vocal, visual and movement behaviors.”
The animal and plant kingdom could be as much a part of “the big data revolution as humans”, he concludes.