Scientists investigating the ocean and its microscopic inhabitants north of Oahu and in Monterey Bay, Calif., have made the fourth major discovery of a new group of bacteria using light energy. Ocean study reveals
new microorganismsThe discovery of new bacteria
alters views on oceanic food websBy Helen Altonn
haltonn@starbulletin.comThe latest finding of new phototrophic microbes (light-using bacteria) was reported in a recent issue of the British journal Nature by microbiologist Edward DeLong at the Monterey Bay Aquarium Research Institute, Moss Landing, Calif.
David Karl, University of Hawaii biological oceanographer who wrote an accompanying "News and Views" about the research, said more new forms of life can be anticipated.
"We now recognize fewer than 10 percent of the bacteria in nature, so the book on biology and ecology will surely need to be re-evaluated and probably rewritten once we have a full inventory of life forms in the sea," he said.
Scientists believed that phytoplankton, a plant containing the green pigment chlorophyll, made up the main ocean population that turns sunlight into food. But now they're finding new types of organisms that get energy directly from light, and they're rethinking their theories of oceanic food webs.
DeLong and colleagues at the Institute for Genomic Research in Rockville, Md., used genomic DNA sequencing techniques to analyze genetic blueprints of the microbes.
He said the new technologies "are letting us see for the first time some of the basic properties and characteristics of some of the most abundant organisms on the planet.
"It's a true discovery period, and these discoveries are helping us to better understand the structure and function of the oceanic ecosystem, the living ocean."
DeLong said microbes particularly "represent the organisms that are responsible for maintaining all the major energy and nutrient cycles on Earth."
"Since we know that man is impacting the environment more heavily now than ever in our history, it becomes increasingly important to better understand ecosystem dynamics, ecology and biogeochemical cycles," DeLong said.
Karl, head of the Laboratory for Microbiological Oceanography in the UH School of Ocean & Earth Science & Technology, and his colleagues have reported other new microorganisms found in the Ocean Time-series program at Station Aloha 60 miles off Oahu.
These and other discoveries of unusual and abundant groups of marine organisms in the past two decades tell scientists they do not know as much as they thought about life in the sea and the flow of carbon and energy through food chains, he said.
"The diversity of microbes in the sea is large and getting larger with each new discovery," Karl said, adding that caution is needed as plans are made for future uses of the sea.
"If we do not have a full inventory of life forms on the planet, how can we, as scientists, answer questions from the public and from our decision-makers about pollution, land use practices and global environmental change?"
Karl said he believes a large, global-scale experiment that is under way "will lead to more attention being given to marine microorganisms, which though invisible to the naked eye are largely responsible for the air we breathe (they supply the oxygen) and much of the food we eat (they serve as the base of most marine food webs).
"Since the oceans cover nearly three-fourths of our planet, these are issues of major proportion."
University of Hawaii