The ROV Video Feed: Commercial-free Science
The ROV went down to the bottom yesterday, 500 meters beneath the surface, near the head of Baltimore Canyon. The crew that runs the submersible had been busy, making adjustments and some last minute modifications. They were working on the robotic arm, which has a lot of moving parts that all have to work together like an intricately choreographed ballet. If you change one part, then many others have to change too. The whole ROV is much the same way, and can be a beautiful thing one minute and very temperamental and frustrating the next.
Previous to this expedition the ROV was in the Gulf of Mexico where it got entangled on an oil rig and lost its connection to the surface. It had to be rescued by another ROV. There is some minor damage visible on the foam shell that helps keep it neutrally buoyant. We were lucky to have retrieved this vehicle without major damage before our expedition.
The ROV was purchased several years ago for about $300,000 and since then has undergone some extensive modifications. There is an HD video camera and two still cameras aboard that can be aimed and zoomed by remote control. Other cameras monitor the bio box and the rear of the craft. Lots of lights are available for the video, and flashes for the still cameras. Two laser beams aimed forward provide a fixed scale of 10cm so the size of objects is easy to determine.
The robotic arm can extend, bend, rotate, and grasp, both delicately and strong enough to crush pencils. It also has a suction tube, attached next to the robotic hand that can vacuum up shrimp, small fish, and bits of coral. These are transported to 8 specimen buckets, mounted on a carousel at the back of the ROV that can be rotated so material from different sites is kept separate. There is a large bio box, with a lid, which has bow, middle and aft chambers for larger items. Seven collecting jars, called quivers, are available for smaller items, and these can be divided into three vertical chambers if desired, and then they are closed with a rubber stopper. Finally, there are two Niskin bottles for taking water samples. The bio box can be removed, and replaced with a carousel holding 18 quivers if so desired.
The ROV is tethered to a small but heavy “depressor” unit, about 150 feet behind the ROV, from which the ROV can move around freely without being tugged on by the ship at the surface. The depressor is in turn connected to the surface with a cable (the umbilical) that is about an inch thick, through which run all of the electrical connections controlling all of the instruments on the ROV and through which we receive data and video in real time.
One person operates the small motors of the ROV to steer it and make it rise and fall. Another person operates the robotic arm. The ROV is controlled from a trailer, which is really a modified storage container. It is packed with electronics and a giant air conditioner keeps the whole thing at refrigerator temperatures. The University of Connecticut owns the whole thing.
Two scientists are assigned to each dive segment. The cameras are controlled by the lead scientist, who can pan and tilt the camera and does a verbal annotation. The assistant takes notes on what was collected, where and when it was collected, and into which collecting bucket it was placed. Similar records are maintained of any photo taken.
On the way down to the bottom, there were lots of small shrimp and the occasional fish. Then the bottom arrived, a vast expanse of mud with a few crabs. Then there were a few fish and some anemones. Suddenly, a large stand of Paragorgia arborea loomed into view. Known as bubblegum coral, it was fantastically red colored. Nearby were what appeared to be pink and white varieties. Game on!