Oceanographers can learn a lot about marine food webs and chemical vents at the bottom of the ocean by analyzing the larvae of tiny plankton that live along the seafloor. But moving a robot vehicle to precise spots along the pitch-black, irregular surface is difficult. So is sifting through large volumes of water to snag the fragile critters, barely visible in size, without tearing them apart. In July the Sentry autonomous underwater vehicle took a new sampler, called SyPRID, to six methane seeps in the Atlantic Ocean between North Carolina and Nantucket, in some cases more than 2,000 meters down. SyPRID, nicknamed Plankzooka for its bazooka rocket-launcher shape, retrieved 132 distinct species. The precision sampling, says Carl Kaiser, vehicle program manager at the Woods Hole Oceanographic Institution, “will allow scientists to analyze the difference between larvae at 2.5 meters from the bottom versus five meters or, say, 10 meters away from a vent versus 50—great comparative studies.”

Illustration by Dan Foley