FALMOUTH, Mass. (AP) — Two torpedo-shaped marine robots have been busy detecting, and protecting, rare North Atlantic right whales in the Gulf of Maine.

The robots, called gliders, were deployed by Woods Hole Oceanographic Institution researchers between mid-November and early December.

The gliders have acoustic monitoring instruments that help detect calls from four species of baleen whales, including right whales. On the recent deployment, the gliders found nine right whales, leading regulators to request a voluntary speed restriction to help prevent ship strikes on whales.

Traditional whale detection methods include human surveys from ships or planes. But the robot gliders don't need good weather to work and they can "see" underwater.

Their mobility is also an advantage over an existing system which uses underwater microphones placed on buoys near a shipping lane into Boston to listen for whales.