From investigating the potential of time crystals to developing self-guided bullets and intelligence-gathering bioengineered spy plants (yes, you read that right), the Defense Advanced Research Projects Agency (DARPA) has come up with some absolute crackers in its time.

Now for their latest batshit crazy enterprise, scientists at DARPA are looking to employ snapping shrimp as a radar detection system to spot incoming enemy subs. The idea being that the rambunctious clicking, clacking, and snapping of the shrimp bounce off nearby objects, affecting patterns in the "underwater soundscape" that can then be picked up by nearby sensors.

To make this story even better, the team investigating the super-sleuthing crustaceans has decided to name the project Persistent Aquatic Living Sensors – or PALS for short.

But why snapping shrimp? The snapping (or pistol) shrimp can be found in tropical and subtropical coastal waters worldwide, where they stun their prey using the sounds generated by their giant claw. They are able to shut their claw at extraordinary speeds of 100 kilometers per hour (62 miles per hour), producing tiny air bubbles and generating sounds of 190 decibels at close range. To put it into perspective, that is louder than a .22 caliber rifle shot and powerful enough to break a small glass jar. The sound itself is reminiscent of popcorn popping or sausages sizzling in a pan and is near-constant, allowing scientists to monitor any subtle changes.

Because they are ubiquitous in the world’s oceans and because they are self-sustaining, the team at DARPA hope they can offer a cheap but reliable way to detect human-made objects attempting to keep a low profile. Those human-made objects being enemy subs and, ever increasingly, underwater drones, which have the impressive but disarming ability to glide through the water near-silently. 

Or, as DARPA said in a statement: "Because marine organisms are ubiquitous in their environments, self-replicating, and largely self-sustaining, sensing systems that use marine organisms as their foundation would be discreet, cost-effective, and provide persistent undersea surveillance with a minimal logistical footprint."

But the snapping shrimp is not the only marine creature DARPA scientists have their eye on. As part of the PALS program, researchers are testing various sea beasties to calculate their potential for subterfuge. This includes schools of fish that may adapt their behavior in the presence of underwater drones, bioluminescent organisms that could display distinctive light patterns when faced with a mechanic vehicle, and microbes that may expose the magnetic signature of nearby metallic objects.

"What we call the biological soundscape is the collection of all the sound that all of the animals are making underwater," Alison Laferriere, a scientist at Raytheon BBN Technologies who is leading the team on snapping shrimps, told Discover, referring to the idea that animals that are naturally attuned to their surroundings will adapt their movements and behavior in response to an intruding force. By tracking these changes, the thinking goes, scientists may be able to use marine organisms as a biological alert system to detect unwelcome visitors.

"What we’re interested in, specifically, is monitoring the soundscape and determining if there's a change in the soundscape in some way when an underwater vehicle passes through," Laferriere added.

The next steps involve lab testing, which – if successful – will be followed by more tests. This time in the ocean. 

[H/T: Discover]