Small wonders Unravelling the paradoxes of plankton

Scientists are using technology to sequence the DNA of microscopic marine life for the first time-to help us learn more about ourselves

- Brianna Randall

Off the west coast of Greenland, a17-metre aluminium sailing boat creeps through a narrow, rocky fjord in the Arctic twilight. The research team onboard, still bleary-eyed from the rough nineday passage across the Labrador Sea, lower nets to collect plankton. This is the first time anyone has sequenced the DNA of the tiny marine creatures that live here.

Watching the nets with palpable excitement is Prof Leonid Moroz, a neuroscientist at the University of Florida's Whitney marine lab. "This is what the world looked like when life began," he told his friend Peter Molnar, the expedition leader with whom he co-founded the Ocean Genome Atlas Project (Ogap).

Moroz gestures toward Greenland's glaciated valleys. The rapid warming here is replicating conditions from 600m years ago, when complex life forms began appearing. "We're sailing through deep biological time right now," he said.

Moroz and Molnar's mission is to classify, observe, sequence and map 80% of the sea's smallest creatures to learn more about ourselves, and the health of the planet.

Plankton and humans do not have much in common at first glance. But studying marine organisms has led to breakthrough understandings about our own brains and bodies. Observing the electrical discharges of jellyfish taught us how to restart the heart. Sea slugs showed us how memories form. Squid taught us how signals spread between different parts of the brain. Horseshoe crabs demonstrated how visual receptors work.

An unusual aspect of Moroz and Molnar's research trips is that they are unlocking plankton's secrets onboard sailing boats rather than enginepowered vessels - and they are not alone in this endeavour.

"Large oceanographic vessels can cost $100,000 a day, which can quickly bankrupt your research organisation," said Chris Bowler, an oceanographer with France's National Centre for Scientific Research and a scientific adviser to the Tara Ocean Foundation.