An autonomous underwater vehicle known as the REMUS SharkCam has been used in the UK for the first time to observe the behaviour of basking sharks in the Inner Hebrides, off the west coast of Scotland.

The groundbreaking technology, designed and built by the Oceanographic Systems Laboratory at Woods Hole Oceanographic Institution (WHOI), USA, is set to reveal the secret lives of the world’s second largest fish – a species that little is known about, despite being prevalent in the region’s waters.

The research team, which included colleagues from the University of Exeter, UK, World Wildlife Fund (WWF), UK, Sky Ocean Rescue, UK, and Scottish Natural Heritage (SNH), hope the images captured by the AUV will strengthen the case for creating the world’s first protected area for basking sharks in this part of the sea.

The team used SharkCam to track sharks once they were tagged and disappeared beneath the water’s surface. The robot collects wide-angle, high definition video of their behaviour from a distance, as well as high quality oceanographic data, such as ocean temperature, salinity, biological productivity and bathymetry, which shows how far the sharks are off the bottom of the seafloor.

Initial footage from the innovative SharkCam deployed off the coast of Coll and Tiree shows the sharks moving through the water column, potentially searching for food, feeding near the surface and swimming close to the seafloor.

It is hoped that further analysis of the many hours of video footage from the AUV, as well as visuals from towed camera tags attached to the sharks and the deployment of advanced sonar imaging, will uncover even more about the underwater behaviour, social interactions, group behaviour and courtship of the elusive species.

“Every time we deploy REMUS SharkCam, we learn something new about the species we are studying,” said WHOI research engineer Amy Kukulya and SharkCam principal investigator. “We’re able to remove the ocean’s opaque layer and dive into places never before possible with this groundbreaking technology, answering questions about key species and revealing new ones.”

Fieldwork for the project took place in July in the proposed Sea of the Hebrides Marine Protected Area (MPA) – one of four possible MPAs currently under consultation by the Scottish government.

The area is one of only a few worldwide where large numbers of basking sharks are found feeding in the surface waters each year. It is suspected that basking sharks may even breed in Scotland – an event that has never before been captured on film.

“Our seas and coasts are home to some incredible wildlife,” said Dr Jenny Oates, WWF SEAS programme manager. “As our oceans come under increasing pressure, innovative technology like the REMUS SharkCam can reveal our underwater world like never before and help to show why it must be protected. It is essential that we safeguard our seas, not just to enable magnificent species like basking sharks to thrive, but because all life on earth depends on our oceans.”

The REMUS SharkCam technology – owned and operated by WHOI – was originally developed to track great white sharks, but has been adapted to also be able to track sea turtles, smaller sharks and now basking sharks.