For the first time ever, National Oceanic and Atmospheric Agency (NOAA) scientists have tracked endangered sea turtles remotely — using an underwater robot. The Autonomous Underwater Vehicle (AUV) uses side-scan sonar technology to detect the creatures swimming and resting on the sea floor at a known turtle hotspot near North Carolina.
“This is the very first time that we used our AUVs to look for living creatures,” says Rob Downs, AUV project manager at NOAA's Office of Coastal Survey. His team used the devices to inspect damage in Texas after Hurricane Ike, as well as checking for navigational obstructions at a naval air station in Jackson Hole, Fla. and searching for debris in a Florida Keys National Marine Sanctuary.
Unlike man-made debris, turtles are difficult to spot because they have rounded shells and spend most of their time on the sea floor. "They're living natural objects, they move about," says Downs. The turtle carapace does not strongly reflect sonar waves the way steel or concrete does. "We're looking for aspects of the acoustic signature that are turtle-shaped," explains Larisa Avens, a research fishery biologist at NOAA fisheries. The team found juvenile and adult Loggerhead turtles, as well as Kemp's Ridley turtles in Cape Lookout Bight in North Carolina's Outer Banks.
The AUV has a communication range of just 1500 meters, or less than a mile, so is best suited to shallow water exploration. It propels itself through the water along a pre-programmed course, powered by a lithium ion battery and surfacing periodically to get its bearings.
The expedition helped the AUV experts train their staff and gather meaningful data for the turtle researchers at the same time, says Downs.
Monitoring sea turtle populations is essential if you're trying to develop conservation strategies and measure their success. Seeing the population rebound after the introduction of Turtle Excluder Devices into fishing nets was one of her most rewarding moments, says Avens.
According to this post on the NOAA website, scientists usually count sea turtles from the air as they surface. The robot method allows for quicker and more accurate counting.
The AUVs expand the range of surveillance because they can access difficult areas without disturbing the sea turtles, who tend to avoid vessels for fear of being struck. "It's a quieter, smaller object just passing through," as Avens puts it — unnoticed by the endangered animals rooting through the mud.
External link: http://mashable.com/2014/06/24/underwater-robot-sea-turtle/