News | 31 August 2023

Underwater robots: the future of ocean exploration and beyond


In this August's "In Depth" section, we dive into the world of underwater robotics and the future of ocean exploration.

Underwater robots are useful for studying hydrothermal vents, deep sea habitats and much more / ICM-CSIC.
Underwater robots are useful for studying hydrothermal vents, deep sea habitats and much more / ICM-CSIC.

Robots can function under extreme conditions that far exceed the limits of the human body or even human-occupied vehicles. As such, these devices allow us to safely explore even the most remote ocean habitats on this planet, such as those of the deep sea.

They have already proven invaluable for studying hydrothermal vents, which are dangerous deep-sea habitats where super-heated waters erupt from of the seafloor, and Challenger Deep, which is a trench that at almost 11,000 m below the surface is the deepest point in our oceans. Moreover, without human-occupants, these robots can remain in these habitats for long periods of time extending from days to years. This means that robots can provide us with unique insights into how marine habitats and their associated ecosystems can change over time instead of the short-term “snapshot” of information typically obtained by submarines or scuba divers.

At the Institut de Ciències del Mar (ICM-CSIC), there are several research groups specializing in applications of underwater robotics. One of these, the Functioning and Vulnerability of Marine Ecosystems group, recently partnered with Göteborg University (Sweden) to test a novel robot that uses tank-like caterpillar treads to crawl along the bottom of the ocean. This “crawler” is fitted with a high-resolution camera and an arm-like manipulator, which makes it a versatile platform for monitoring and interacting with benthic habitats. In addition, the crawler tethered to a surface buoy holding a Wi-Fi antenna.. To pilots the crawler, you therefore only need to stay in range of the Wi-Fi antennae at the surface while the robot is free to explore the seafloor.

The trails of the crawler took place at Göteborg University’s Kristineberg Marine Research Center in one of the many beautiful fjords of Sweden. Using the crawler, the team collected valuable footage on local marine ecosystems while opportunistically using the manipulator to collect marine litter.

For the first time ever, the team also successfully used a Virtual Network Provider to establish a remote connection with the Centre de Desenvolupament de Sistemes d'Adquisició Remota i Tractament de la Informació at Universitat Politècnica de Catalunya (where one of the earlier prototypes of the crawler is currently installed at the Observatori Submari Cablejat – OBSEA) who then piloted the crawler in real-time at a distance of almost 3,000 km away! This demonstration was particularly exciting as it opens new possibilities for using the crawler in long-term studies that can remain active regardless of where in the world the operating team is based.

Active restoration

Overall, the trails were a great success. The demonstrated stability of the crawler, its impressive payload capacity, and its adaptable manipulator make it capable to fine-scale operations such as replanting sessile species (e.g., corals, gorgonians). While such active restoration efforts are typically undertaken by scuba divers or snorkelers in shallow-water systems, in the deep-sea this is achieved via the “badminton” method.

In the badminton method, sessile species are attached to heavy substrates and then dropped from boats in the hope that these species will survive the fall to the seafloor. Using a crawler however, deep-sea specimens can be handled with greater care making it suitable for restoring more fragile species. As such, the crawler will likely be incorporated in two ICM-led National Projects: PLOME and BITER. Specifically, PLOME aims to develop a network of underwater robots to conduct long-term monitoring of marine ecosystems, whereas BITER aims to monitor and restore fishery-impacted species and ecosystems on the Catalan coast.

Crawlers will also be a key component of the recently funded EU Horizon grant project: REDRESS. This international project will focus on the active restoration of deep-sea habitats and the Functioning and Vulnerability of Marine Ecosystems group is directly responsible for managing monitoring the ecological impacts of these restoration efforts.

Crawlers are powerful tools for ocean exploration that complement more conventional marine robots, such as propeller driven mid-water or surface machines. Working in tandem, these devices can provide comprehensive data throughout the entire water column. Moreover, testing and development of these devices does not just have benefits for exploring oceans on our planet but also for those on other planets throughout our ecosystem.

We already know that ice-covered oceans exist on the moons of Saturn (e.g., Enceladus) and Jupiter (e.g., Europa), and one day in the future, it will be robots, not humans, that will first venture into these waters. Maybe a crawler, not too dissimilar to the one used by our scientists at ICM-CSIC, maybe part of this interplanetary voyage of discovery.