The recordings recorded by sea lions with light video cameras give the researchers an insight into previously unexplored areas of the sea floor off the south coast of Australia.

The one on August 7th in Frontiers in Marine Science 1 include detailed cards of the sea floor, which was created by the combination of videos recorded by the animals with a machine learning model. The camera shots also show details about the distribution of different habitats and species.

"These are particularly deep and remote offshore habitats that cannot be achieved with the usual studies that one would carry out from a boat," says co-author Nathan Angelakis, ecology and evolutionary biology at the South Australian Research and Development Institute in West Beach. "With the data we collect, we basically explore new parts of the ocean that have not yet been mapped."

unknown waters

Knowing the sea floor is important for several reasons, including marine preservation, navigation and prediction of dangers such as tsunamis. "You can't manage what you did not measure," says Steve Hall, head of the partnerships at the ocean -going organization Seabed2030 based in Liverpool, Great Britain.

worldwide only 26% of the sea floor are mapped in high resolution. This is partly due to the challenges of exploring the deep sea, where the pressure is extremely high and the lighting conditions are low. Researchers typically map the sea floor with remote -controlled underwater vehicles or by throwing cameras from surface ships - but both methods are time -consuming and expensive.

Angelakis and his colleagues tried a comparatively simpler approach by taking advantage of the help of wild Australian sea lions ( neophoca cinerea ). These animals spend most of the time on the sea floor, looking for food along the continental shelf, the area of ​​the ocean that stretches from the coast. The researchers suspected that by pursuing the movements of the sea lions, they could collect information about the shape of the sea floor and the distribution of different habitats.

The authors attached sensors to neoprene plasters, which they stuck on the back of eight adult females from two of the largest Australian sea lion colonies. The equipment, which included GPS trackers, cameras and movement sensors, was designed in such a way that it was small and not a hindrance and less than 1% of the body weight of the sea lions weighed in order not to affect animals or to influence their behavior. After completing the project, team members were able to remove the sensors from the plasters without damaging the fur of the sea lions.

Together, the sea lions took up 89 hours of video material, which included six different habitats of the sea floor, from mere sand to algae meadows.

The researchers used the film material to evaluate biodiversity in these areas and to compare the places visited by the two colonies. They also used the videos to check the accuracy of a mechanical learning model that was developed to predict the habitat of the sea floor using variables such as sea temperature and the distance to the coast. They found that the model was more than 98% precisely, so they then used it to map the habitats of the sea floor in the surrounding areas. "One of the great strengths of the study is to use the collected data to predict other unknown areas," says Angelakis.

The team also wants to use the sensor data to explore how factors such as depth and nutrient supply influence the habitat distribution and biodiversity on the sea floor. This could help researchers "to further explore the ecological value of different habitats and marine areas for sea lions," says Angelakis, which could strengthen the efforts to preserve.

The use of sea lion assembly sensors is a "very good method to obtain high-resolution data from a difficult to access area," says Hall. He suggests that in future studies, the researchers could equip the sea lions with additional sensors in order to collect data on the physical and chemical properties of marine floors.