Industrial Electronics

Underwater robot investigates mid ocean “twilight zone”

24 June 2021
Mesobot can be piloted remotely through a fiberoptic cable attacked to a marine vessel or released from its tether to follow pre-programmed missions. It can also autonomously track a target at depths of up to 3,000 feet. Source: WHOI

Researchers at the Woods Hole Oceanographic Institution (WHOI) have developed an underwater robot designed to take high-resolution images of the mid-ocean region known as the “twilight zone.”

Called Mesobot, the robot will be able to track and record slow-moving and fragile zooplankton, gelatinous animals and particles without disturbing the natural habitat.

Scientists hope that the robot will provide a greater understanding of the role these creatures play in transporting carbon dioxide from the atmosphere to the deep sea. Additionally, the experiment will examine how commercial exploitation of twilight zone fisheries might affect the marine ecosystem.

"Mesobot was conceived to complement and fill important gaps not served by existing technologies and platforms," said Dana Yoerger, a senior scientist with Mesobot. "We expect that Mesobot will emerge as a vital tool for observing midwater organisms for extended periods, as well as rapidly identifying species observed from vessel biosonars. Because Mesobot can survey, track, and record compelling imagery, we hope to reveal previously unknown behaviors, species interactions, morphological structures, and the use of bioluminescence."

Co-developed by the Monterey Bay Aquarium Research Institute (MBARI), Mesobot was able to record dinner plate jellyfish ramming a siphonophore, which narrowly escaped the jelly’s venomous tentacles. It also recorded a video of a giant larvacean, which appears to be nearly motionless but is riding internal waves that rise and fall.

"Mesobot has the potential to change how we observe animals moving through space and time in a way that we've never been able to do before," said Kakani Katija, principal engineer at MBARI. "As we continue to develop and improve on the vehicle, we hope to observe many other mysterious and captivating animals in the midwaters of the ocean, including the construction and disposal of carbon-rich giant larvacean 'snot palaces.'"

How it works

The hybrid robot is outfitted with a suite of oceanographic and acoustic survey sensors.

It can be piloted remotely through a fiber optic cable attached to a marine vessel or released from its tether to follow pre-programmed missions. It can also autonomously track a target at depths of up to 3,000 feet.

The autonomous mode will allow Mesobot to one day follow a target animal for more than 24 hours without human intervention, enough time to observe its migration from midwater twilight zone to the surface and back.

Future studies from Mesobot could provide insight into animal behavior during diel vertical migration, where a vast number of diverse creatures migrate at night.

The full research can be found in the journal Science Robotics.

To contact the author of this article, email

Powered by CR4, the Engineering Community

Discussion – 0 comments

By posting a comment you confirm that you have read and accept our Posting Rules and Terms of Use.
Engineering Newsletter Signup
Get the GlobalSpec
Stay up to date on:
Features the top stories, latest news, charts, insights and more on the end-to-end electronics value chain.
Weekly Newsletter
Get news, research, and analysis
on the Electronics industry in your
inbox every week - for FREE
Sign up for our FREE eNewsletter