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Sharks are Pentagon's
latest spy recruits By Roger Highfield, Science Editor Photos by Cory Hatch
Researcher Jelle Atema uses shark sensory organs to control the animals' movements. Shark brain implants that could turn the fish into "stealth spies" are being studied in a research project funded by the Pentagon. Swimming in a ship's wake, a remote-controlled shark could track an enemy vessel's movements without being noticed, and under its own power. The navy also hopes to exploit sharks' natural ability to sense delicate electrical gradients and follow chemical trails left by a vessel. The research builds on developments in brain implant technology which have already seen scientists controlling the movements of fish, rats and monkeys. Walter Gomes, of the Naval Undersea Warfare Centre in Newport, Rhode Island, said the team's next step would be to implant the device into blue sharks and release them into the ocean off the coast of Florida. The project, funded by the US Defence Advanced Research Projects Agency (Darpa), is described today in New Scientist. Another group, led by Prof Jelle Atema at Boston University, has already used implants in the olfactory centre of the brain to "steer" spiny dogfish in a tank, using radio commands sent to an antenna on the fish that stands proud of the surface. However, radio signals will not penetrate water, so the naval engineers plan to communicate with the sharks using sonar beamed from naval acoustic signaling towers, according to a paper presented by Mr Gomes to the Ocean Sciences Meeting in Honolulu, Hawaii, entitled Autonomous Shark Tag with Neural Reading and Stimulation Capability for Open-ocean Experiments. The towers, which are already in the area, are suitable for relaying messages to a shark up to 200 miles away. The team has designed a sonar receiver shaped like a remora fish, which species often attaches itself to sharks. The scientists will be particularly interested in the sharks' health to see how long they can control their movements in any one session without harming the fish. Other Darpa-funded researchers are working on using implants to record brain activity in sharks in order to understand which neurons are fired by scents, electrical or magnetic fields. These signals help the fish to navigate and offer the reward of food, so could in theory be manipulated for surveillance work. Fisheries scientists are also investigating the use of neural implants to control the behavior of farmed fish. The plan is to let the fish loose to forage for themselves and retrieve them when they are large enough to harvest. A team led by Prof Barry Costa-Pierce, of the University of Rhode Island, has already developed implants that can make fish surface on command in studies that focus on tuna, cobia and salmon. In Johnny Mnemonic, William Gibson wrote about Jones, a military surplus dolphin cyborg.
"He rose out of the water,
showing us the crusted plates along his sides, a kind of visual pun, his grace
nearly lost under armor, clumsy and prehistoric. Twin deformities on either side
of his skull had been engineered to house sensor units. Silver lesions gleamed
on exposed sections of his gray-white hide."
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