When eight young northern elephant seals suddenly began showing up at a deep-sea observatory, researchers were taken by surprise. Their repeated visits to the research site, otherwise a speck in the vast, dark ocean, wasn’t a chance occurrence, a new study reveals. The mammals were likely drawn to the area by the observatory’s sonar pulses. A team of scientists made the discovery while studying the effects of light and bait on fish behavior at a research site located 645 meters (2,116 feet) deep, at Barkley Canyon, off the west coast of Canada. The researchers used a high-definition camera, hydrophone and acoustic imaging sonar, a system that transmits sounds to map and image features and animals. While reviewing the footage, the team unexpectedly came upon at least eight male elephant seals (Mirounga angustirostris), ages 4-7, who visited the observatory multiple times between June 2022 and May 2023. “These repeat visits suggest that the seals may be using the general site as a focal foraging area,” study lead author Héloïse Frouin-Mouy, a marine biologist and bioacoustician at the University of Miami, U.S., told Mongabay in an email. The footage gave the researchers some unique insights into elephant seal behavior in the deep sea. For instance, the videos showed that the young male elephant seals preferred to eat sablefish (Anoplopoma fimbria) over snailfish (Careproctus spp.). “This was evident when an elephant seal we named Dennis mistakenly caught a snailfish while attempting to capture a sablefish, only to quickly release it,” Frouin-Mouy said. “This is important…This article was originally published on Mongabay
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