The agency wants to know if sea life ranging from bioluminescent plankton to goliath grouper can serve as components of underwater surveillance systems capable of detecting the enemy’s oceangoing drones, large nuclear submarines and other underwater vehicles. The research effort is called Persistent Aquatic Living Sensors (PALS).

Many marine animals respond audibly or visibly to sound, optical, electromagnetic and chemical shifts in the water around them. For instance, schools of black sea bass change their behavior when disturbed by underwater vehicles, and certain microbes react to the magnetic signatures of submarines. Existing surveillance technology can pick up this behavior but typically has treated it as background noise.

“The PALS program was developed to leverage the great sensitivity that organisms have in the ocean to changes in their environment,” says Lori Adornato, manager of the initiative, which is administered by the federal Defense Advanced Research Projects Agency (DARPA).