Coexisting in a Sea of Competition (IMAGE) Woods Hole Oceanographic Institution Caption The high diversity of phytoplankton has puzzled biological oceanographers for a long time. There are over 200,000 species of of these tiny marine plants that use sunlight and nutrients to grow and reproduce at the ocean's surface. Credit Courtesy of Samantha DeCuollo,University of Rhode Island Usage Restrictions With proper credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.