Drones are Helping Scientists Weigh Seals in Antarctica

It’s always nice to see a positive drone story. Today we’ve heard about a new way in which drones are helping with conservation efforts. A project in one of the most remote parts of the world, Antarctica, has shown that aerial photography can be used to effectively weigh and measure leopard seals.

Keeping track of predators at the top of the food chain is an easy way to perform a health check on an entire ecosystem. It’s for that same reason that Ocean Alliance has used drones to collect whale snot in recent times. A similar proof of concept has been underway in Antarctica, with a team from the NOAA Fisheries’ Southwest Fisheries Science Center working with Aerial Imaging Solutions.

The concept is pretty simple. The team has developed software that can accurately measure the length and weight of leopard seals in the wild, just from aerial photographs. The technique has proved to be accurate, too. The scientists have tested the accuracy of the measurements by catching and measuring the same seals after they were captured on camera from above. They found the length measurements to be accurate to within about two percent. The weight measurements were within four percent.

Drones save researchers time and money

Sacrificing a small amount of accuracy is well worth it considering the upsides to using drones. Most notable are the time and effort saved. Usually, it would take a crew of five over four hours to catch a single leopard seal. With a drone, each of the 15 leopard seals required to be measured for the study were captured within 20 minutes.

So that’s less stress for the researchers and less stress for the seals, which didn’t take much notice of the drones so long as they stayed above 75 feet.

The paper, published today in the online journal PLOS ONE, titled ‘An accurate and adaptable photogrammetric approach for estimating the mass and body condition of pinnipeds using an unmanned aerial system’, goes into much more detail.

 

“We continue to develop technologies to gather the data we need to manage fish and wildlife in a safer, less expensive way,” said Douglas Krause, a research scientist in the Southwest Fisheries Science Center’s Antarctic Ecosystem Research Division (AERD), and lead author of the paper demonstrating the new research method.

“We’re certainly excited because we can get that much more work done, in less time, and at lower costs than ever before.”

“We can get measurements that are just as good, or better, without ever bothering the animals,” said Krause. “Catching a single seal can take hours, but the drone can photograph every seal on a beach in a few minutes.”

“When we think about indicator species in Antarctica, we often think about highly abundant species such as penguins,” said Jefferson Hinke, a co-author and research scientist in the AERD. “But top predators, such as leopard seals, are also sensitive to their environment and monitoring them provides additional information on the status of the Antarctic ecosystem.”

Checking out the weight of leopard seals gives scientists a strong understanding of the health and abundance of krill. In turn this information can help fishery managers assess how much the fishing fleet can catch each season.

“We’re always looking for more efficient ways to collect data that informs decisions on how to manage these important resources,” said George Watters, director of the AERD. “The better we understand the ecosystem, the better we can ensure it’s protected for the long term.”