Other Environmental Themes

New Ways of Seeing

Animal tracking has come a long way since the days of Jim Bridger and Kit Carson, 19th-century trappers who relied on their knowledge of animal behavior, footprints, and scat to pursue their quarry. Today's animal trackers have a variety of high-tech tools to draw from, and they believe the insights gained by following the detailed meanderings of fish and other creatures is essential for designing effective conservation strategies. Simply put, if we know where marine animals spend their time, we can identify key feeding and breeding grounds and thereby afford them better protection.

Equipped with radio transmitters and a satellite system scientists can accurately track the migration and, non-migratory movements of tuna, salmon, swordfish, sharks, sea turtles, seals, and other creatures across the globe. Autonomous underwater vehicles have also successfully followed and recorded the vocalizations of baleen whales for five days as part of an ambitious effort to track where these mammals over long periods. Ultimately, these findings could shield endangered whales from fishing gear entanglements, ship strikes, and other hazards.

Although technologies such as this provide clues to a fish's whereabouts, they don't tell us the extent to which fish stocks are depleted or how many fish actually remain in the sea. A new sonar device developed by MIT ocean engineer Nicholas Makris can simultaneously track tens of millions of fish, spread across an area the size of Connecticut, to help identify populations in greatest need of protection.

Federal regulators believe Makris' sensor could offer a valuable complement to existing fish counting methods. "Our mission covers 4 million square miles and 900 species, and anything that gives us new information is helpful," says Steve Murawkski of the National Marine Fishery Service.

Rather than enhance their protection some fear that the same animal-tracking technology could be used to facilitate the more efficient removal of fish from the seas. Given the problems brought on by overfishing, says oceanographer Peter Etnoyer, "one of the last things we need right now is a better way to catch fish."