Robotic Marine Vehicles Explore Celtic Sea 2015-09-30

Scientists in England are using two autonomous marine vehicles to explore the hydrology and biology of the Celtic Sea, an area off Ireland's southern coast defined by its unique marine life. Primarily, they want to know why marine animals are so attracted to this part of the Atlantic Ocean.

Slowly moving just below the surface, a battery-powered submersible glider called Slocum collects data for England's National Oceanography Center in Southampton and the World Wildlife Fund.

Its low energy requirements allow it to stay afloat for up to 30 days, regularly sending reports via satellite about the Celtic Sea's diverse ecosystem.

"We have echo sounders to detect zooplankton and fish, acoustic Doppler current profilers for measuring the currents in the water, wet-lab fluorometers for measuring chlorophyll and organic matter, and a few other specialist sensors as well," said Stephen Woodward, a glider engineer.

As it oscillates through the water, the glider also creates a two-dimensional cross-section map of the sea.

"We're interested in how, for example, the weather events directly affect the water column and in turn does that affect productivity and then again in fish and further up the food chain, cetaceans or seabirds," said marine biologist Lavinia Suberg.

Meanwhile, the autonomous catamaran C-Enduro has embarked on its own mission in the Celtic Sea. Powered by solar panels and a wind turbine, it can stay afloat for months, sending data about the so-called biodiversity hot spots.

"Biodiversity hot spots are areas in the ocean that are usually particularly productive. Productive areas attract zooplankton, and that in turn attracts fish," Suberg said. "Areas of enhanced or elevated biomass of fish often attract marine mammals and seabirds in turn."

Using autonomous marine vehicles sharply reduces the cost of exploring the seas with crewed floating labs, so scientists can devote more time to laboratory analysis of the collected data. They say it will give them a better understanding of this area's needs for future management and protection.