Monday, 25 March 2013

One-Eyed, Six-Legged, Flying Whale Chaser

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, California.

For years, Perryman has experimented with military reconnaissance techniques to track marine life. He collaborates with former Navy officer Don LeRoi of Aerial Imaging Solutions in Connecticut. Their latest device is a hexacopter. With six quiet engines, internal gyroscopes, an accelerometer and a GPS, the mechanical bird has great maneuverability. For the past two years, Perryman has snapped shots of penguin and seal colonies in Antarctica with the hexacopter. Future trips include a jaunt to Alaska to survey stellar sea lions.

"When you get into aggregations of thousands of animals, humans are lousy at determining how many animals there are," Perryman said. "With photography, you can go back in time and see something you maybe wouldn't have noticed," he adds.

In February and March, Perryman and LeRoi helped an international science team track sperm whales near New Zealand by capturing whale photos with the copter. The scientists attached tracking tags to the whales, and knowing their size and shape from the photos improves understanding of how the whales dive underwater, Perryman said. It was the first ship-based test for the 'copter, named Archie by the scientists onboard.

Even with a gyroscope-stabilized platform brought on ship to calibrate the hexacopter's stabilizing systems, Archie ended up in the ocean on one flight. "We picked it up and rinsed it off with fresh water, and within a week, we were flying again," Perryman said. For their ease-of-use and cool aerial photos and videos, hexacopters are also popular with hobbyists, who can build a bird with off-the-shelf parts.

Perryman said it would cost $60,000 to design a hexacopter for marine research, and he hopes to find funding for a pilot trainer. "We need to build a tough little aircraft that has all the same components as our sampling bird, but one you can crash and knock it into things and fly into trees and it keeps on ticking," he said.

Researchers at Murdoch University in Australia are also testing a small fixed-wing plane to survey and count marine life, including dugongs and humpback whales. Perryman sees potential for using aerial devices to place tracking tags on animals, collect skin specimens and sample breath, which contains information about an animal's health. Currently, scientists invest many hours following whales and other species to collect this information and place tags, typically in small rubber boats.

The photographic detail achievable with these vehicles could also help differentiate between species, Perryman said. "In the Antarctic, there may be four undescribed species of killer whales. If you're going to ask questions about size and shape and growth, you have to have a way of collecting very accurate information without handling the animals, and that's what this can do,".

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