Aerial Drones Give NOAA Scientists a New Perspective
Wayne Perryman with a group of penguins on Livingston Island in Antarctica.
A hovering aerial drone.
Leopard seal on Livingston Island bares its teeth at researchers. Using a drone to get close to these aggressive predators might be a good idea. Credit: Ray Buchheit.
October 3, 2012
From a rare rocky outcrop on the otherwise ice-covered surface of Livingston Island, near the end of the peninsula that Antarctica extends like a tentacle toward South America, a team of scientists from NOAA's Southwest Fishery Science Center is about to launch a whole new era in marine mammal research. They just have to wait for the wind to die down.
When it does, biologist Wayne Perryman flips a switch, and an unmanned aerial vehicle the size of a hubcap shoots straight up into the sky, its sharp insect buzz fading quickly as it races away. This drone has 6 helicopter rotors, allowing it to take off vertically and hover motionlessly, and a high-resolution digital camera. Perryman maneuvers it into position above a small group of leopard seals hauled out onto the rock, and then starts taking pictures.
Very little is known about the role of leopard seals in this ecosystem, and the drone, which Perryman also uses to study penguins and fur seals, will provide a better look. “You can tell a lot about the reproductive and nutritive condition of an animal based on its shape,” he says. From the photos, scientists can measure the length and width of individual animals and so generate estimates of their weight. By monitoring weight gain among the seals, scientists hope to better understand the energetics of the species and how they structure their ecological community through predation.
A typical season of fieldwork involves anaesthetizing a sample of animals on the ground and physically examining them. “The reason you want to work with them remotely is that it’s safer for the human and safer for the seal,” says Perryman. “A leopard seal is about a thousand pound animal, it’s mostly teeth, and it’s a very dangerous animal to work with.” They’re also particularly sensitive to anesthesia, which means that there’s a very fine line between using too much, which can be dangerous for the animal, and using too little, which can be dangerous for everyone."
Perryman served as a hydrographic surveyor in the Navy during the Vietnam War. Soon after, he joined NOAA and helped pioneer the use of aerial surveys to monitor dolphin populations in the Pacific. He’s spent most of his career working with high-end military equipment, but the digital revolution has moved consumer technology to the cutting edge. Equal parts biologist and hacker, Perryman now flies drones that are custom built out of readily available parts.
During the upcoming field season, Perryman will hand the controls of the drone to NOAA scientist Doug Krause, the lead researcher on the leopard seal study. Krause and his team will collect data both by air and on the ground, allowing them to calibrate the method for converting remote measurements into weight estimates. Although these methods are still being developed, aerial drones will soon be a standard tool in the marine mammal biologist’s field kit.
Richard Merrick, the Chief Science Advisor for NOAA Fisheries, expects drones to expand the reach of science. “Unmanned aerial systems will open the door for us to conduct research in a wider range of environments. These technologies are going to help us do this research more safely, and they are very cost-effective,” said Merrick, citing the example of remote islands where surveys from manned flights are ineffective and dangerous due to low cloud cover.
Perryman also has some ideas about where the new technology will take him, such as inside the plume of a whale as it blows. By following closely above a whale, then swooping in to sample the plume at just the right moment, a drone can yield data on hormone levels, genetic markers, and other clues to the animal’s condition. “We’ve got a technology that works really well,” Perryman says, and he and other NOAA scientists are quickly imagining new ways to use it.