Review of Genetic Variation in Marine Phytoplankton Species and the Ecological Implications

AbstractGenetic variation within marine phytoplankton species is now well established within local populations: individual cells have different reproduction rates and various biochemical and physiological characteristics that are the result of genetic variability. In general, however, differences among cells within a population are relatively small. In some species that live in more than one habitat or water mass, genetic differentiation has developed. This leads to much larger genetic differences between populations, often as large as the differences between species. Although less information is available on seasonal genetic changes in phytoplankton populations, it appears that significant genetic changes occur in highly seasonal coastal waters but not in the more constant oceanic waters. In addition to individual physiological tolerance, genetic variation is a mechanism by which many marine phytoplankton species have expanded their ecological distribution in time and space and phytoplankton ecological s...