We designed Mesobot, our new hybrid robot, specifically to study life in the ocean twilight zone. It can maneuver under its own power for more than 24 hours, using its cameras and lights to slowly follow individual animals while making a variety of other measurements and even taking samples. We call it a hybrid robot because it can be controlled either by human pilots through a lightweight tether or it can run autonomously with no tether. For example, we can pilot the vehicle while tethered to locate an interesting target, then we can release the tether and the vehicle can continue on its own.

Mesobot was carefully designed to avoid disturbing the animals it observes. It is relatively small and has a streamlined form.  Large, slow-moving propellers allow it to hover and transit with minimal disturbance of the surrounding water. Mesobot carries standard white lights and red lights which many deep-sea species can’t see. Red lights allow Mesobot to observe animals without either frightening or attracting them.

In addition to taking high-quality images, Mesobot can also accommodate different types of auxiliary devices. As one example, Mesobot often carries a sampler that pumps seawater through filters to collect environmental DNA—or eDNA—traces of DNA that were left behind by animals recently in the area. These samples will help scientists understand what types of animals are living in the zone, even if they never actually see them.

Mesobot is a collaborative effort by WHOI, the Monterey Bay Aquarium Research Institute (MBARI), Stanford University, and the University of Texas Rio Grande Valley. Mesobot development and at-sea operations have been funded by the National Science Foundation and the Ocean Twilight Zone project.


Unique capabilitiesMesobot can follow slow-moving animals automatically
Operational configurationstethered remotely operated vehicle or untethered autonomous vehicle
Maximum depth1000m
Endurancegreater than 24 hours using lithium-ion batteries
Camerastwo monochrome cameras for stereo imaging, 4K color video/still camera for scientific imaging
Size and weight1.5m long, 1.5m high, 1 meter wide, weight 250kg
Payload capabilityup to 20kg for added samplers and sensors
Explore Mesobot by clicking on the buttons below.