From 2009 to 2013, the research schooner Tara traversed the globe, carrying a multinational team of scientists. They surveyed the critical foundation of the marine food chain (a foundation we know dangerously little about): plankton, bacteria, protists, viruses and small animals. All in all, they found more 35,000 different kinds of organisms — many of them previously unknown to science. Read all about it!
Top photo: Tara in the Arctic Ocean (A.Deniaud/Tara Expéditions)
Photo 2: Plankton collected in the Pacific Ocean. (Christian Sardet/CNRS/Tara Expéditions)
Photo 3: A male Sapphirina copepod collected in the Mediterranean sea. (Christian Sardet/CNRS/Sharif Mirshak/Parafilms/Tara Expéditions)
Photo 4: A tiny
crustacean copepod, a spider crab larva, an amphipod, a baby squid, a Phronima amphipod, and
an Atlantic pteropod mollusc. (Christian Sardet/CNRS/Tara Expéditions)
Photo 5: A small medusa (a relative of the jellyfish) collected in the Mediterranean sea. (bepoles/Tara Expéditions)
Map of the voyage, based on a graphic by bepoles/Tara Expéditions.
The open sea is a pelagic ecosystem (Pelagic is a term that refers to a part of the sea or ocean, that is not near the shore nor near the bottom), in wich the living components are plankton an nekton.
Plankton (singular plankter) are a diverse group organisms that includes microalgaes (phytoplankton) -both first gif- and animals (zooplankton) that float along at the mercy of the sea’s tides and currents.
Several structural features and behaviors have evolved to keep afloat organism that are not strong swimmers. some plankton species display a number of interesting adaptation that help them avoid predation. Many planton and nekton swim by cilia, flagella, appendages and undulatory tails
Some are babies (correct term is larva) that will grow into strong-swimming, non-planktonic adults. Others will remain plankton for their entire lives, also jellyfish. Most of the plankton in the ocean are micro-algaes, It is estimated that 80% of the oxygen on earth is produced by phytoplankton.
Scientists unveiled the most comprehensive analysis ever undertaken of the world’s ocean plankton, the tiny organisms that serve as food for marine creatures such as the blue whale, but also provide half the oxygen we breathe. The researchers spent 3-½ years aboard the schooner Tara, taking 35,000 samples of plankton from 210 sites globally, determining the distribution of the organisms, tracking how they interact with one another and carrying out genetic analyses.
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.