Plankton study maps millions of genes

May 22, 2015, 4:44 PM EDT
Fresh water plankton under stroboscopic flash light. Mites (Hydrachnidiae), Ostracodae and Cladocera swimming.
Getty Images

Scientists spent 3-1/2 years aboard the schooner Tara, taking 35,000 samples of plankton from 210 sites around the world. They looked at the distribution of plankton, and conducted genetic analyses in the largest DNA sequencing project conducted in ocean science. Reuters reports:

Plankton include microscopic plants and animals, fish larvae, bacteria, viruses and other microorganisms that drift in the oceans.
"Plankton are much more than just food for the whales," said Chris Bowler, a research director at France's National Center for Scientific Research, and one of the scientists involved in the study published in the journal Science.
"Although tiny, these organisms are a vital part of the Earth's life support system, providing half of the oxygen generated each year on Earth by photosynthesis and lying at the base of marine food chains on which all other ocean life depends."
The scientists conducted the largest DNA sequencing effort ever done in ocean science, pinpointing around 40 million plankton genes, most previously unknown.
Much of the plankton was more genetically diverse than previously known. However, the genetic diversity of marine viruses was much lower than anticipated.
By removing carbon dioxide from the atmosphere and converting it into organic carbon via photosynthesis, plankton provide a buffer against the increased carbon dioxide being generated by the burning of fossil fuels, Bowler said.
So far the scientists have analysed 579 of the 35,000 samples collected, presenting the results in five scientific papers.
Dr Bowler said the research was transforming our understanding of these ocean communities.
"For the viruses, we describe about 5,000 virus communities - only 39 of these were previously known.
"And for protists - unicellular organisms - we estimate something like 150,000 different taxa.
"There are about 11,000 formally described species of plankton - we have evidence for at least 10 times more than that."