Video captured by sea lions equipped with cameras has enabled unexplored areas of the Australian seabed to be mapped, an approach that could save the hands of oceanographers in cases where robotic underwater surveys are too expensive or technically difficult.
The images also revealed unknown aspects of the life of Australia’s sea lion, an endangered species that spends days at sea foraging in the waters of the continental shelf.
“These data are useful both for mapping important habitats for threatened species such as the Australian sea lion and, more generally, for mapping unexplored areas of the seabed,” said Nathan Angelakis, a PhD student at the University of Adelaide and lead author of the paper. to study in the Frontiers in Marine Science.
Angelakis and his colleagues recruited eight Australian sea lions (Neophoca cinerea) and attached to their furry devices with a camera, motion sensor and GPS transmitter.
“We attached the instruments to adult females so that we could retrieve the equipment a few days later when they returned to land to nurse their young,” explained Angelakis.
“We used GPS receivers with a satellite link, which meant we could track their location in real time and know when they returned to the colony.”
The camera and GPS transmitter can be seen on the back of this beached sea lion (Nathan Angelakis)
From the videos collected, a total of 89 hours, the researchers identified and mapped six benthic habitats, i.e. habitats of the seabed, such as basement reefs and underwater meadows.
The data also provided insight into sea lions going down to the bottom and spending 2-3 minutes still, Angelakis said.
“They will wait for the fish they like to pass to chase or ambush them. We also have videos of sea lions spinning over rocks. And we collected images of a mother carrying her little child to the sea.”
The researchers now plan to continue the study by adding sensors that will measure water quality.
Globally, only a quarter of the ocean floor has been mapped at high resolution.