Robot goes on trawling, but not for fishes

WASHINGTON, USA: A new robot spent most of July trawling the muddy ocean bottom, about 40 km off the California coast - somewhat like the robotic rovers Spirit and Opportunity that traversed Mars' dusty surface.

The new robot, Benthic Rover, has been providing scientists with an entirely new view of life on the deep seafloor, besides monitoring climate change impact on the deep sea.

Benthic Rover is the result of four years of hard work by a team of engineers and scientists led by Monterey Bay Aquarium Research Institute (MBARI) project engineer Alana Sherman and marine biologist Ken Smith.

About the size and weight of a small compact car, Benthic Rover moves very slowly across the seafloor, taking photographs of the animals and sediment in its path.

It stops every three to five metres and makes a series of measurements on the community of organisms living in the seafloor sediment. These measurements will help scientists understand the mystery of how animals on the deep seafloor find enough food to survive.

Most life in the deep sea feeds on particles of organic debris, known as marine snow, which drift slowly down from the sunlit surface layers of the ocean.

But even after decades of research, marine biologists have not been able to figure out how the small amount of nutrition in marine snow can support the large numbers of organisms that live on and in seafloor sediment.

MBARI researchers have been working on Benthic Rover since 2005, overcoming many challenges along the way.

The most obvious challenge was designing the rover to survive at depths where the pressure of seawater is about three tonnes per square inch. To withstand this pressure, the engineers had to shield the robot's electronics and batteries inside custom-made titanium pressure spheres.

To keep it from sinking into the soft seafloor mud, the engineers outfitted the vehicle with large yellow blocks of buoyant foam that will not collapse under extreme pressure, said an MBARI release.

This foam gives the rover, which weighs about 1,400 kg on land, a weight of only about 45 kg in seawater.

©IANS