Remote-Controlled Sharks: Next Navy Spies?
for National Geographic News
|March 6, 2006|
For millions of beachgoers, the sight of a dorsal fin sticking out of the water means a shark with one thing on its mind: prey.
But what is really going on in the shark's head? If scientists knew, could they control some of the animals' thoughts and movements?
Jelle Atema, a marine biologist at Boston University in Massachusetts, hopes to find the answers.
He is one year into a four-year project to develop brain implants that could allow humans to remotely guide some shark behavior.
The study is funded by a U.S. $600,000 grant from the Arlington, Virginia-based Defense Advanced Research Projects Agency, known as DARPA.
According to an article published last week in the British magazine New Scientist, the U.S. military hopes to use the technology to turn sharks "into stealth spies, perhaps capable of following vessels without being spotted."
On the Odor Trail
According to Atema, sharks have a large snout, sensitive nostrils, and a good portion of their brain dedicated to smell. They use their keen sense of smell to locate food and mates.
The brain implants consist of a series of electrodes that allow scientists to see which neurons fire in a shark's brain in response to a smell.
"We want to understand what kind of neurological info it's getting and is processing when it is swimming in a real odor trail," Atema said.
The research complements earlier work in which Atema showed how lobsters use smell to determine where they fit in their local community.
(Read "Lobsters Use Smell Test to ID Buddies, Bullies.")
The marine biologist says his research goal is to understand how animals sense their environment. The implants, he says, are a window to the inner workings of animal brains, a "holy grail" of neuroscience.
Similar research, he added, is done on humans with magnetic resonance imaging, or MRI. The noninvasive technique can give scientists a view of which neurons fire in the brain in response to various stimuli.
Once the researchers understand how shark brains work, they may be able to use the electrodes to mimic stimuli, Atema says, effectively feeding instructions directly into the fish's brain.
The team's work, combined with MRI studies, may eventually help scientists find a cure for paralysis in humans, he said.
From Tank to Ocean
Atema and his colleagues discussed their progress on the shark brain research on February 21 at the American Geophysical Union's Ocean Sciences Meeting in Honolulu, Hawaii.
To date, the researchers have succeeded in outfitting spiny dogfish, a small shark species, with neural implants and stimulating the brain region sensitive to smell.
When the researchers stimulate the left side, the fish turn to the left. When the right side is stimulated, the fish turns right. Stronger signalsmimicking a stronger smellcause the fish to turn more sharply.
"We want to create in an animal brain the kind of stimulus pattern they normally get from a true odor plume in the environment," Atema said.
The implants were tested using radio transmitters to communicate with fish in a laboratory tank.
Walter Gomes, a project engineer with the Naval Undersea Warfare Center in Newport, Rhode Island, told the ocean science meeting that the next step is to outfit blue sharks with the devices and release them in the open ocean off the Florida coast.
Since radio waves are unreliable in open water, the researchers plan to use sonar to communicate with the sharks, according to New Scientist.
The U.S. Navy has acoustic signaling towers in the region capable of relaying messages from ship to shark over a distance of 186 miles (300 kilometers), the magazine reported.
The shark sensor research group is one of several teams working on implant technology with the goal to monitor and influence animal behavior, according to the British magazine.
John Chapin at the State University of New York Health Science Center in Brooklyn has developed implants to stimulate a part of the rat brain wired to whiskers.
(Read "Scientists 'Drive' Rats by Remote Control.")
Understanding these processes could allow people to use rats in disaster response scenarios.
A team led by Tim Tricas at the Hawaii Institute of Marine Biology is using implants to study how hammerhead sharks use electric-field sensors to navigate.
Atema said that, as with any scientific research, these studies raise ethical concerns that are best addressed by public forums.
"Any research being done could be abused, and that needs to be controlled by society," he said.
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