MBARI’s flagship, the R\/V David Packard, sailed on September 14 to meet them for the Chasing Marine Snowstorms expedition<\/a>, which was scheduled through September 18. On day one, the crew planned to put a drifting sediment trap over the side. It hangs from a float at the surface and catches whatever’s sinking at five different depths, down to 1,640 feet (500 meters). Each stop gets three collection tubes plus a time-lapse camera, so the team can see when things land.<\/p>\n The trap also carries an acoustic beacon. The drones were set up to listen for it and follow the trap as the current pushed it along, running nonstop up-and-down passes through the top 656 feet (200 meters) and photographing the plankton and debris in it. So the trap catches what’s sinking while the drones photograph what’s still floating up top, and they’re both doing it in the same moving water.<\/p>\n I’ll admit that’s a pretty clever setup.<\/p>\n MBARI calls it marine snow, which sounds a lot nicer than it is. Basically, it’s a slow drizzle of mucus, poop, dead plankton and assorted organic gunk sinking from the surface toward the bottom. We’ve written about the tracked rover MBARI sent 13,100 feet down off California to measure how much of this stuff gets eaten on the bottom<\/a>.<\/p>\n You’re probably wondering why anyone would bother building robots to chase it. The short answer is carbon. Phytoplankton, the tiny plant-like drifters near the surface, soak up carbon dioxide as they grow. Bigger plankton eat them, poop and die, and all of it sinks. MBARI says that trip down can keep carbon out of the atmosphere for decades, sometimes centuries, and scientists call the whole process the biological pump.<\/p>\n Durkin laid out the problem pretty bluntly when MBARI introduced SINKER, one of its seafloor cameras: “Who makes these particles? How fast do they sink? How big are they?” Apparently climate models still don’t handle the biology behind sinking carbon very well. That’s a slightly awkward gap, since biology is a big part of what decides how much of that carbon stays down there.<\/p>\n The instruments doing the “stay” half have been down since April. SINKER’s plugged into MARS, which MBARI lists at 2,923 feet (891 meters) down, so it never runs short of power and sends images to shore in real time. It’s got five cameras. Three of them time particles as they drop through a tube, and two more look up at the plate they land on, which a brush sweeps clean every two hours.<\/p>\n I love that last detail. Somebody at MBARI had to design a windshield wiper for the Pacific floor.<\/p>\n Farther offshore, a battery-powered camera called the Sedimentation Event Sensor, or SES, sits on a mooring almost two miles (about three kilometers) down. MBARI describes it as a sediment trap that photographs what it catches rather than keeping it. The plan for this cruise was to pull both instruments up, service them and send them straight back down.<\/p>\n Pretty far, it turns out. MBARI’s published specs<\/a> put the LRAUV at about 6.6 feet long, a foot across and 242.5 pounds. That’s the base vehicle, though. MBARI hasn’t said what these two weigh with their imaging gear bolted on, and it’s probably more than 242.5 pounds. NOAA lists the camera-carrying LRAUVs it borrows from Woods Hole at about 9 feet and 250 pounds, and we’ve already covered how that version steers by sliding its own battery pack back and forth<\/a>.<\/p>\n The whole thing’s built around sipping power. MBARI says the vehicle is optimized for science gear drawing about eight watts, a little less than the roughly nine watts the FTC says an LED bulb needs to match an old 60-watt incandescent. MBARI’s engineers once kept an early one out for 23 days, and it covered more than 1,100 miles (1,800 kilometers) in that time.<\/p>\n Which means you can send a pair out days ahead of a ship and have them already on station when it shows up. That’s basically what happened here.<\/p>\n So why don’t they just park everything on the bottom and wait?<\/p>\n A camera on the seafloor tells you what showed up. Following the water tells you where it came from and what happened to it on the way down. Plankton patches drift, and the water off Central California gets shoved around by upwelling plumes and the California Current, so a trap that stays in one place can end up sampling a different crowd from one day to the next. Tracking one body of water with drones lets the team connect what’s living in the top 656 feet to what the trap catches under it.<\/p>\n If you don’t follow ocean weather, El Ni\u00f1o’s what happens when the winds along the equator ease off and warm water piles up along the Pacific coast of the Americas. Off California, that warm water weakens the upwelling that normally brings cold, nutrient-rich water up to feed the plankton.<\/p>\n![\"MBARI](\"https:\/\/www.autonocion.com\/us\/wp-content\/uploads\/2026\/09\/MBARI-LRAUV-Tethys-long-range-AUV-drone-1024x576.jpg\")
What exactly is falling down there?<\/h2>\n
Two cameras have been on the seafloor since April<\/h2>\n
![\"MBARI](\"https:\/\/www.autonocion.com\/us\/wp-content\/uploads\/2026\/09\/MBARI-LRAUV-Tethys-long-range-AUV-2-1024x576.jpg\")
So how far can one of these things go?<\/h2>\n
El Ni\u00f1o is back, and NOAA expects a big one<\/h2>\n