Using stereo cameras and detection algorithms, Mesobot analyzes and tracks the movements of its subjects. Yoerger and his colleagues demonstrated the robot’s ability at a depth of 650 meters in Monterey Bay, which caught them after hunting jellyfish. Even more spectacular, for half an hour he continued to drag a fragile animal called the larvae, which resembles a tadpole and builds a huge “house” of mucus to filter food. (The robot eventually disturbed the very sensitive structure outside the house, but neither did the structure inside the house and the animal itself.) Based on the tests, the team believes the robot will work for more than 24 hours and reach depths. 3,200 feet.
For now, Mesobot cannot collect the animals, but may use the children’s absorption system in the future. Observing sea creatures with the camera will not tell you what they eat, for example, and so where they enter the food web would require dissection. If you want to study their physiology, you also need a physical specimen. “The idea would be to follow an animal for a while and then catch it. I think that’s very doable, ”Yoerger says.
The Mesobot AirPods may seem like a big case, but compared to other manned divers and ocean robots, it’s pretty compact. Perhaps the most famous of them all Alvin, Which also operates the Woods Hole Oceanographic Organization. It weighs 45,000 pounds and can only be launched from a specific ship. Building smaller Mesobot sizes is cheaper and easier to implement, which will open up more platforms for researchers. “That’s another big win,” says Singh, of Northeastern University. “He doesn’t need all these extra things – big lathes, big boats.”
Scientists have long known that species make daily vertical migrations, but so far they have had to study them to determine where they are caught at different times when caught at different depths or using sonar. After all, a footprint is not given a way to crush a jellyfish or a larva to control its movements in detail. “We have so few observations about many fish,” says Luiz Rocha, a fish curator at the California Academy of Sciences, who studies reefs in the sunset zone but has not been involved in this new work. “We don’t know how they swim, much less how they eat or how they reproduce.”
Scientists don’t have a great idea of how different species that travel through mid-water interact; for example, which prey do the prey follow up and down the water column? Are animals migrating in narrow schools or in a more scattered way? Or, how can an increase in ocean temperatures affect how a particular species migrates, which in turn can affect others in its food chain? Oceanographers might try to keep up with divers, but anything hidden other than Mesobot would scare everyone away. “But if you have a robot that can be submerged for up to 24 hours and you follow a fish or a group of fish all the time, you can think about studying these phenomena,” says Rocha.
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