Sea lions are helping scientists map the ocean floor and doing a great job

Earth’s ocean floors represent one of the least explored frontiers on our planet. Despite significant technological advancements, mapping these vast underwater landscapes poses considerable challenges, primarily due to the high costs and complexities involved.

Traditional methods often depend on remotely operated vehicles (ROVs), which, while effective, face limitations imposed by weather conditions and ocean depths.

In an exciting development, a team of researchers in Australia has introduced an innovative solution to these obstacles. They’re harnessing the unique skills of endangered Australian sea lions to carry cameras, offering fresh insights into the enigmatic habitats of the seabed.

By leveraging the natural behavior of these animals, scientists can gain a new perspective on underwater ecosystems that was previously unattainable.

Brain behind the initiative

Nathan Angelakis, a PhD student at The University of Adelaide and The South Australian Research and Development Institute (SARDI), is making significant strides in marine science research.

His team’s recent publication in Frontiers in Marine Science illustrates how collaborating with marine mammals can provide us with invaluable insights into ocean exploration.

“Using animal-borne video and movement data from a benthic predator is a really effective way of mapping diverse benthic habitats across large areas of the seabed,” Angelakis explained.

“These data are useful both for mapping critical habitats for an endangered species such as the Australian sea lion, and more broadly, for mapping unexplored areas of the seabed.”

Mapping the ocean floor is difficult

The seabed is a vital hub of biological diversity. It supports a wide array of marine life and enhances the overall biodiversity of our entire planet.

However, what we actually know and understand about these unique habitats is still very far from a complete record, primarily due to the challenges associated with exploring them.

It’s often said that we know more about the surface of the Moon and Mars than we do about the ocean floor. While this might sound surprising, it is 100% true!

This disappointing fact reflects the reality of our current deep sea exploration capabilities and the challenges involved in studying the deep ocean.

Traditional seabed mapping techniques, such as remotely operated vehicles (ROVs), are effective but often costly and face significant difficulties in the deep ocean’s extreme conditions.

Sea lions and seabeds

To address these obstacles, Angelakis and his team have turned their focus to the Australian sea lion (Neophoca cinerea), an endangered species found along Australia’s southern and western coasts.

By equipping agile sea lions with lightweight cameras and tracking devices, they successfully gathered crucial data on seabeds and marine habitats across the continental shelf, revealing previously hidden regions of the ocean floor.

The study observed eight adult female Australian sea lions, with cameras and GPS tracking instruments attached to them that weighed less than 1% of their body weight.

“We deployed the instruments on adult females so we could recover the equipment a few days later when they returned to land to nurse their pups,” Angelakis explained.

“We used satellite-linked GPS loggers on the sea lions, which meant we could track their position in real-time and knew when they had returned to the colony.”

Data goldmine from sea lions roaming seabeds

Over two to three days, these marine “scientists” captured 89 hours of footage – a goldmine for researchers.

It covered a range of benthic habitats encountered during their dives, including macroalgae reefs, invertebrate boulder fields, and bare sand areas, to name a few.

This diversity of environments provided a wealth of data, granting researchers the ability to map critical habitats on the continental shelf.

“The sea lions from both locations covered quite broad areas around the colonies. In our calculations, we kept the area in which we predicted habitats small to maximize the precision of our predictions,” Angelakis enthused.

“This allowed us to model benthic habitats across more than 5,000 square km of the continental shelf.”

Mapping the continental shelf

One breakthrough of this research is the ability to predict large habitat areas across the southern Australia continental shelf.

The team used machine learning models incorporating decades’ worth of oceanographic and environmental data, including temperature trends, ocean currents, and nutrient levels.

This approach allowed the team to model benthic habitats across more than 5,000 square kilometers (1,930 square miles) of the continental shelf.

Preserving Australian sea lions (Neophoca cinerea)

Besides revealing the unseen benthic habitats, the study also provided crucial information about the endangered Australian sea lion. Over the past four decades, their population has dwindled by more than 60%, making this study invaluable to their conservation efforts.

Australian sea lions are among the rarest and most endangered sea lion species. Their distinctive appearance makes them easy to identify. Males exhibit a rich dark brown coat, while females and juveniles have a lighter, creamy-gray fur.

These medium-sized marine mammals showcase notable size differences, with males reaching lengths of up to 8 feet and weighing around 660 pounds, whereas females typically measure about 6 feet and weigh around 220 pounds.

What sets Australian sea lions apart is their unique breeding cycle, occurring every 17 to 18 months, unlike the annual cycles of most other sea lion species. Additionally, these highly social creatures are often observed in groups, engaging in playful behaviors in and out of the water.

Sea lions, seabeds, and future research

The inclusion of Australian sea lions in seabed mapping marks an important breakthrough in marine exploration.

Utilizing animal-borne cameras to map seabed habitats not only provides cost-effective solutions but also extends our reach to areas inaccessible by traditional equipment.

As Angelakis and his team have shown, collaborating with animals in scientific research can lead to discoveries that would otherwise remain veiled.

By viewing the ocean through the eyes of a predator, we gain a renewed appreciation for the creatures that inhabit them and deepen our understanding of marine environments.

As this research illustrates, sometimes letting nature take the lead is the best way to unravel the unknown.

The full study was published in the journal Frontiers in Marine Science.

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