When engineer Eric Berkenpas decided to help scientists capture fur seals in Australia as part of a study to learn more about the animals' diets, he thought the venture would be fun. He was wrong. We have to admit, we never imagined catching a 500-pound seal involved giant butterfly nets.

Seal -stampede _2015_05_07
Image: Arnould/National Geographic. Screengrab from YouTube

Berkenpas had recently developed a "critter cam" for capturing marine animal behaviour on video, and as director of National Geographic’s remote imaging programme, he made his way to the remote island of Kanowna off the coast of Victoria to help scientist Dr John Arnould use it.

Arnould would be deploying the cameras to learn more about what the seals were eating in the wild. Exciting, as the only way to do this in the past had been to dig through the animals' scat (poop). "The critter cam allowed us to see what the animal was eating when it was actually eating it – to get a better idea of how the poop studies were working," explains Berkenpas. 

The cameras are designed to be light and uninhibiting, and are attached with a seal-safe glue. They're programmed to pop off so that the researchers can retrieve their data later on, so this is just a temporary tagalong for the animal. The attachment process is completed as quickly and gently as possible, and within no time the seals are happily back in the water.

Catching the seals, on the other hand? Well, that can be tricky. "So we were [putting] cameras on the seals. I thought it looked like a lot of fun ... But then the scientists started a stampede of seals towards the ocean. So there's this tidal wave of fur and teeth just coming down the mountain at me," Berkenpas recalls.

A few hours and a lot of four-letter words later, the last camera was deployed, and the footage came rolling in. The team learned that not only were the seals deep-diving to find fish (which they are known to do), but they were also eating on the way back up to the surface. One intrepid seal was even caught on camera munching on a pufferfish, a behaviour that's apparently never been observed before. 

Thanks to information provided by the footage, Arnould has also gleaned that underwater gas pipelines may be attracting marine life, and that the seals follow these pipelines for foraging and navigation purposes. 

"It's amazing what you'll put yourself through to get the project done," he says. "But it's all for the sake of science!" says Berkenpas.

Top header image: Michael Sale, Flickr