Mesobot Dives into the Twilight Zone for the First Time

Engineers prep mesobot for it's first ocean deployment off the Rachel Carson
Woods Hole Oceanographic Institution (WHOI) engineers prepare Mesobot for its first ocean deployment off the Monterey Bay Aquarium Research Institute (MBARI) R/V Rachel Carson, testing all the systems on deck one last time before the new robot is on its own in the ocean. Mesobot is a collaboration between Woods Hole Oceanographic Instituion, Monterey Bay Aquarium Research Institute, Stanford University, and the University of Texas Rio Grande Valley.

The newly developed deep-sea robot, Mesobot, dove in the open ocean for the first time last week during a successful test and evaluation cruise in Monterey Bay, California. The development of Mesobot is a collaboration between Woods Hole Oceanographic Institution (WHOI), Monterey Bay Aquarium Research Institute (MBARI), Stanford University, and the University of Texas Rio Grande Valley. The robot is designed to let scientists observe the twilight zone by autonomously tracking individual animals for hours, or even days, without disturbing the environment or disrupting their behavior.

Mesobot using red light in a test tank
Mesobot is specially equipped with red light, something many animals in the ocean twilight zone can’t detect. The robot has a sophisticated tracking system, using the red light to lock onto a target and follow it autonomously for hours or even days.

The tests began in MBARI’s test tank June 10, 2019. Using algorithms developed by MBARI and Stanford University, Mesobot was able to track test targets like a tennis ball as it moved through the tank. In particular, the vehicle was able to precisely track moving and stationary targets using very low, slowly varying thruster action, which we believe do not disturb sensitive animals.

Dana Yoerger and Jon Howland look out a door while mesobot is deployed
Lead senior scientist, Dana Yoerger, and principal engineer, Jon Howland, both from WHOI, look out as Mesobot is lowered into the ocean. Putting a new vehicle into the water for the first time can be both very exciting and extremely nerve wracking. They will put Mesobot through different trials testing all the different complex systems they have been working on for years.

We deployed Mesobot in the open ocean over three days from MBARI’s R/V Rachel Carson. The vehicle made five dives to depths of several hundred meters and we were able to evaluate its basic function and controllability. It performed well as a remotely operated vehicle (ROV) when connected by its lightweight fiber optic tether, and just as well when running untethered. We gathered important data on the vehicle’s performance, including its speed and endurance. The vehicle also actively tracked a target for several minutes, showing the same slow, deliberate motions that were demonstrated in the test tank.

Mesobot is hoisted over the side of a research vessel
Mesobot is deployed on the MBARI R/V Rachel Carson for the first time in June of 2019.

We are grateful to our hosts at MBARI for their hospitality and cooperation as well as the crew of the R/V Rachel Carson for their expert operation of the vessel.