On a Quest for Quiet

Oceanographer and ocean engineer Brennan Phillips runs the Undersea Robotics and Imaging Laboratory at the University of Rhode Island (URI) in Kingston, Rhode Island, where he and his students specialize in creating novel systems for oceanographic research and deep-sea exploration. He is also a familiar face at BIOS, having spent time at the Institute in 2019 testing the development of a controllable, miniaturized camera system for deep-sea exploration, called DEEPi.

In December, Phillips returned to BIOS for another round of tests, this time as part of a joint project with the Naval Undersea Warfare Center (NUWC), the Navy’s research, development, and engineering center for submarines and autonomous underwater systems. Their project investigates how marine organisms in deep water and midwater regions behave around underwater robots, also known as remotely operated vehicles (ROVs).

Scientists use ROVs to reach deeper depths and study organisms that might be disturbed by the presence of divers. These robots are connected to a ship on the surface by a tethered cable and manipulated by skilled pilots on the ship’s deck or control room. An ROV can be equipped with multiple scientific sensors that collect data about the ocean, such as water temperature and salinity; video or still cameras to capture images of the organisms; and a variety of robotic manipulator arms.

But with all of these features, ROVs often come with another, less desirable, trait: noise.

In 1934, American naturalist William Beebe and engineer Otis Barton made ocean exploration history by riding in a spherical steel diving vessel, called the Bathysphere, to a depth of 3,028 feet (928 meters) off the south shore of Bermuda near Nonsuch Island. This feat made them the first to observe deep-sea marine organisms in their natural habitat. The unpowered submersible vehicle turned out to be ideal for making such observations.

“Beebe and Barton had the simplest form of ROV with the Bathysphere,” Phillips said. “It had no thrusters, dim lights, and no noise.”

On his recent visit, Phillips came to Bermuda to “try to get back to those less intrusive systems, but with newer technology. Right now, we know we’re scaring away animals with ROVs and submarines that are too big, too bright, and too loud.”

Over a period of two weeks, Phillips and a team of seven experts in engineering and oceanography from URI and the NUWC led a field investigation to see if their compact ROV Deep Reef could operate from one of BIOS’s small research vessels. Deep Reef is equipped with special equipment, including two low-light cameras that can image bioluminescent (or light-producing) animals, and an acoustic system that uses sound waves to “see” where organisms, such as fish populations, are in the water. Phillips said the ROV is the smallest (about the size of two large suitcases), quietest, and darkest package possible while also supporting the equipment necessary to investigate the midwater animals that researchers hope to study.

Midwater ecosystems, those located between depths of 100 to 500 feet (30 to 50 meters), are some of the least studied areas of the world’s ocean. ROVs like Deep Reef can help scientists learn vital information about these ecosystems and their inhabitants.

This month, Phillips said data analysis continues back in his lab in Rhode Island. Overall, “the project could not have gone better, given the challenges we faced to work safely during the COVID-19 pandemic and with the unpredictable weather conditions that are common during this time of year,” Phillips said. “We are extremely grateful for the opportunity to travel to Bermuda and conduct field research, which was only possible with the collaborative support of BIOS staff.”