Visiting professor uses underwater robots to study ghost colonies

As a boy, Walker O. Smith saw the problems caused by environmental pollution at Lake Erie, where he grew up. Now he is an expert in marine food chains, which he studies using the very latest underwater technology.

Self-guided underwater robots are one of the latest marine research technologies. These small unmanned gliders can spend up to nine months travelling the depths of the ocean, where they gather data such as salinity, oxygen levels, turbidity, temperature or acoustics. From time to time, they rise to the surface and transmit information to a base station via satellite.
“This is powerful technology,” says Professor Smith. “It’s changed the way we see the ocean. With a ship you can stop in one place and take samples on one occasion, but a glider can take samples continuously.”

AS A PROFESSOR OF oceanography, he has been involved in developing new technologies. Thanks to the glider, his team has been able to study how access to food at different depths controls penguins’ day-to-day behaviour.
He is currently in Sweden as one of two researchers to have been awarded the King Carl XVI Gustaf Professorship in Environmental Science for 2014/15. The University of Gothenburg is hosting his visit, and one of his roles involves collaborating with Swedish researchers on developing new underwater technology.

PROFESSOR SMITH’S MAIN area of research is the ecology of phytoplankton and how environmental factors affect its growth, such as in the case of algal blooms. Using another innovative instrument, a video plankton recorder, his research team has discovered a life stage of a species of phytoplankton that has never been observed before, and which they call “ghost colonies”.

The camera was first used in 2012, and can move up and down in the water alongside a vessel at 20 km/h, taking 30 photos a second. This gives hundreds of thousands of images, which are then analysed.
“We would never have been able to observe the ghost colonies without this instrument, as they’re too fragile to see with a microscope.”
Professor Smith’s usual research base is at the Virginia Institute of Marine Sciences at Chesapeake Bay, a brackish water bay on the Atlantic coast. The institute has a long history of marine research. He has also carried out research in Vietnam, China and the Antarctic.

OF ALL THE PLACES where he has worked, he finds the Antarctic the most fascinating. He has been there 35 times and will be returning this autumn, to the American McMurdo research station on the southernmost tip of Ross Island.
“The Antarctic is truly captivating. The sea is stunningly beautiful, and you never grow tired of seeing the icebergs, penguins and seals.”

PROFESSOR SMITH grew up at Lake Erie, one of the large lakes in northeast USA, where he saw the consequences of environmental pollution as a child. The pollution had almost killed the lake by the time the seriousness of the situation was realised and discharges started to be restricted. It has since recovered to some extent, but not completely. He says that if he had been a researcher and taken samples at that time, he could have contributed important knowledge.

HE BELIEVES THAT the biggest threat by far to the sea today is climate changes.
“It’s an enormous threat to the world’s oceans. I hope that we will be independent of fossil fuels within 50 to 100 years. But even if we are, I don’t know whether we will have done enough, quickly enough.”