New Research Dives right in

Art Trembanis’ new research assistant is quite a catch—a fast learner, able to explore underwater for up to 30 hours at a time, at depths extending to 500 feet, diligently collecting valuable data day or night in potentially dangerous conditions.

Of course, this assistant isn’t human but, instead, is a torpedo-shaped underwater robot that was christened this winter at the University’s newly renovated Coastal Sediments Hydrodynamics and Engineering Laboratory (CSHEL). Trembanis, assistant professor of geology and CSHEL director, says he has high hopes for the highly advanced submersible, which he began field-testing in February in the water off Lewes, Del.

Nicknamed DOERRI, for the Delaware Oceanographic and Environmental Research Remote Instrument, the robot is a leading-edge tool equipped with a variable payload of sophisticated scientific equipment. It can carry high-powered computers and other instruments that enable it to “learn” as it operates and to conduct research even when out of reach of radio contact with those on shore. When DOERRI was put through her paces during the February sea trials, researchers say the submersible exhibited a keen ability to swim remotely along the surface and to dive quickly.

Trembanis says the 83-inch-long, 200-pound robot “will provide an unprecedented platform for research and teaching activities” and is well-suited for coastal research throughout Delaware and the Mid-Atlantic region, out to the edge of the continental shelf.

“These robots are ideally suited to conduct work in places and under conditions that standard ship-based efforts and divers are not,” he says, including exploring such hazards as hurricanes and chemical spills. In those situations, Trembanis says, DOERRI could collect vital information that otherwise might be lost. He notes that such vehicles don’t replace standard ship-based operations but are complementary observational tools.

DOERRI, designed by Prizm Advanced Communication and Sias Patterson Inc., was built at the company’s Yorktown, Va., facilities. The robot is a type of Autonomous Underwater Vehicle, defined as an unmanned, untethered mini-submarine that is capable of being trained to conduct missions in rivers, lakes, estuaries and the open ocean. In recent years, Trembanis says, this type of vehicle has moved quickly from an emerging to an applied technology.

Its suite of computer systems allows it to make its own decisions once underwater and out of reach of surface radio communications. For instance, if DOERRI comes across an unexpected barrier, it can decide to back up and chart a new course.

Because DOERRI offers a modular platform for the quick exchange of instruments and sensors, Trembanis says it will allow for collaboration with researchers from a wide variety of colleges and departments at UD, including geology, biological sciences, chemistry and biochemistry and engineering. Additional collaborations are being planned with colleagues from other institutions, industry partners and state and federal agencies.

“One day, DOERRI can be outfitted with chemical sensors to sniff out algal blooms or oil spills, and the next day we can switch to a suite of sensors to map ocean topography or check the sea lanes for hazards,” he says.

The list of potential uses is long and includes the study of hurricanes and other storms, coastal erosion, sediment transport, shipwreck mapping, algal blooms and hypoxia, ocean exploration and fisheries stock assessments. “Now, stock assessment methods are somewhat crude,” Trembanis says. “Basically, researchers toss in a net and count the fish. DOERRI can follow the fish, move with them and identify them on the fly.”

DOERRI also will improve coastal observations, he says. The University is involved in an effort to create a continuous observation network along the coast, providing real-time information on the condition of waterways, and Trembanis says these underwater robots could complement fixed-point sensors with their ability to cover large areas of water.

“If a fixed sensor records low oxygen levels, that can trigger an Autonomous Underwater Vehicle to go out and map the oxygen levels of the adjacent underwater region,” he says.

The submersibles also have national security applications, with the ability to inspect ships and port facilities and undertake mine countermeasures. And, they have the potential to improve environmental safety by searching shipping lanes for unseen hazards, such as the abandoned anchor that ripped a hole in the hull of the oil tanker Athos I on the Delaware River in November 2004.

Trembanis says CSHEL will serve as a development center for Prizm/Sias Patterson, helping to integrate new sensors and develop new behaviors for the vehicles.

Eventually, he says, he hopes to expand the University’s fleet to between six and 12 vehicles stationed on the campus in Newark and at the College of Marine Studies campus in Lewes. He says he is always looking for the “squeaky wheel” students who are eager and motivated to help push the scientific and technical boundaries.

In the next several months, numerous missions are planned for DOERRI, including efforts to map a shipwreck off Lewes Beach, studies of storm impacts along the Delmarva Peninsula, monitoring fisheries habitats in the Delaware Bay and mapping coral reefs off the Florida Keys.  

DOERRI’s hull is white with blue and gold trim, featuring a decal of a diving YoUDee. At its christening in December, Tom Apple, dean of the College of Arts and Sciences, said work with the robot “is poised to revolutionize oceanography.”

“The University of Delaware will be at the frontier of oceanographic research, and the new minisub is going to greatly enhance our understanding of the underwater environment hard by our shores,” Apple said.

Trembanis, who has a joint appointment as an assistant professor of civil and environmental engineering, says a career involving the sea was a natural, given his Greek and Norwegian heritage. He received a bachelor’s degree from Duke University, where he developed an interest in beaches and coastal processes, and was a Fulbright Fellow at the University of Sydney in Australia. He earned his doctorate from the College of William & Mary’s Virginia Institute of Marine Science and did postdoctoral work at the Woods Hole Oceanographic Institution.

 by Neil Thomas