So some biologists are turning to less obtrusive unmanned aerial vehicles (UAVs) to spot species including whales, dolphins, sea lions and penguins. From small helicopters to planes with a 10-foot (3 meters) wingspan, the battery-powered craft could become a popular new tool.

 

"What makes these things so effective is they capture a tremendous amount of information," said NOAA marine biologist Wayne Perryman, based at the Southwest Fisheries Science Center in La Jolla, Calif.

 

For years, Perryman has experimented with military reconnaissance techniques to track marine life.