Where are the ocean's fish? MIT to try to find out

Researchers at MIT, Northeastern and the Naval Research Laborartory have come up with a sensor system that will track fish shoals, or populations, over a 10,000 square kilometer area. Current technology only scans for 100 square meters.

Under standard scanning techniques, ships send high-frequency sonar beams into the ocean. Scientists then track the bouncing of the sonar waves to determine the size of objects in the ocean. The new system uses low-frequency sonar that can travel much greater distances and still return useful information.

"The world's fish stocks are being depleted at a horrible rate," said Nicolas Makris, an MIT mechanical engineering professor and principal researcher on the project, in a prepared statement. "One of the reasons (for the inaccurate counts) is the darkness in the ocean. You don't know what's going on."