Armed with the Gulper, the SIPPER and an array of other high-tech gizmos, a crew of scientists is peering deep into the Gulf of Mexico, looking for tracks of the oil spewed from a well 20 miles away. Unlike crews that have found two possible plumes of underwater oil, the 16 federal and university scientists on the Gordon Gunter cannot use two of their major tools within 20 miles of the wreckage of the Deepwater Horizon drilling rig.
Those are sonar and the Gulper - a robot submarine called an autonomous underwater vehicle, said lead scientist Russell Brown, a biologist for the National Oceanic and Atmospheric Administration's fisheries service. He said sonar and AUV instructions could mess up the audio signals guiding a half-dozen or more other AUVs at work on BP PLC's attempt to shut off the gusher.
"The last thing we want to do is have our equipment interfere with efforts to contain the spill," he said Friday.
The bright yellow, torpedo-shaped Gulper, lent by the Monterey Bay Aquarium Research Institute in California, was named because it can grab a series of 2-liter water samples at different depths and locations, noting depth, temperature and conductivity - an indication of salinity - for each.
Another big assembly of metal, plastic and electronics is lowered to the sea floor by winch, then hauled straight up, taking up to a dozen water samples and the same sort of data as the Gulper as it rises.
The SIPPER - Shadowed Image Particle Profiling and Evaluation Recorder - gets towed behind the 224-foot ship, which is based in Pascagoula, Miss. It uses high-speed digital line cameras to collect pictures of all plankton and other tiny critters and debris that pass through a square tube less than 4 inches across. It will also show oil droplets, said Andrew Remson, a biologist at the University of South Florida.
"It's basically an underwater microscope," he said, showing composites from previous work. The images looked like intricate drawings. Tiny, delicate creatures that would be squashed or broken by a net show up whole, Remson said, but it requires painstaking computer reconstruction.
"We get so many organisms that we trained a computer to tell us what we're seeing," he said. It will take at least two weeks after the cruise's return to analyze the results. But if the ship finds an oil plume, he'll be able to tell whether that area also has more broken bits of dead animals than non-oiled areas, and what tiny plants and animals are most and least numerous.
Nets aren't scorned; the ship also carries a surface plankton net and a set on a machine that will open them at a series of depths from the bottom up.
The earlier work to look for plumes - by university scientists working with NOAA - used light beamed through the water at frequencies that make hydrocarbons fluoresce. Because other organic compounds will do the same, water samples must be analyzed to know for sure what was there.
The eight-day research cruise began Thursday. It will take weeks after the ship returns to Pascagoula to analyze much of the data. Other information from this cruise - and others going on in the Gulf - will be used to decide just where the Gordon Gunter goes.
Friday morning, it had traced about five-eighths of an octagonal path around the well site. On Tom Weber's computer screen late Friday morning, its sonar scan looked like a vertical blue and white ribbon around a section of sea bottom with huge lumps and bumps.
The blue areas indicated a "weak scattering layer," probably from plankton and other marine organisms, said Weber, an acoustician from the University of New Hampshire.
The oil spill work also caused a major change in the ship's standard operations, said the ship's captain, Cmdr. David Score of the NOAA Corps, which runs and maintains the agency's ships and planes.
The ship usually processes much of its drinking water from sea water. Since it's operating in the oil spill, it's carrying 9,000 gallons of water in pillow-shaped 5,000- and 1,000-gallon tanks.
Brown said they also had to replace their standard water collection bottles with Teflon-covered bottles because oil sticks to and reacts with PVC.
And because crude oil is considered hazardous material, people who handle the machinery coming out of the water must wear protective gear and make sure it is set on plastic or absorbent pads.
"We've almost had to change the whole routing of the boat, getting to and from our work areas," Score said.