An underwater robot known as Mesobot is providing researchers with deeper insight into the vast mid-ocean region known as the “twilight zone”, Tech Xplore reports. Capable of tracking and recording high-resolution images of slow-moving and fragile zooplankton, gelatinous animals, and particles, Mesobot greatly expands scientists’ ability to observe creatures in their mesopelagic habitat with minimal disturbance. This advance in engineering will enable greater understanding of the role these creatures play in transporting carbon dioxide from the atmosphere to the deep sea, as well as how commercial exploitation of twilight zone fisheries might affect the marine ecosystem. A paper co-authored by research scientists and engineers from Woods Hole Oceanographic Institution (WHOI), MBARI (Monterey Bay Aquarium Research Institute), and Stanford University, and published June 16 in Science Robotics, outlines the robot’s success in autonomously tracking two gelatinous marine creatures during a 2019 research cruise. High-definition video revealed a “dinner plate” jellyfish “ramming” a siphonophore, which narrowly escaped the jelly’s venomous tentacles. Mesobot also recorded a 30-minute video of a giant larvacean, which appears to be nearly motionless but is riding internal waves that rise and fall six metres. Packaged in an hydrodynamically efficient yellow case, the hybrid robot is outfitted with a suite of oceanographic and acoustic survey sensors. It may be piloted remotely through a fibre-optic cable attached to a ship or released from its tether to follow pre-programmed missions or autonomously track a target at depths up to 1,000 metres.