The College of Science at Basra University organized a seminar (Biological diversity of phytoplankton, ecosystem health guide) for the graduate student Ebtehal Mussa Jaffer ,The study aims to define phytoplankton and its role in the ecosystem and included the use of evidence of biological diversity and water pollution, which are considered indicators that give a clear picture of the environment and phytoplankton is one of the important biological factors in the environment.  Aquatic: It is useful for determining the quality of water and can be used to measure the toxic effects and the degree of risk resulting from human activities on the ecosystem, as it is one of the organisms sensitive to the substances in the water, and the composition and abundance of their communities is related to the nutritional status of the water body.