Representatives of these major microfossil groups are shown in the following figures. These microfossil groups are being studied in sediment cores to reconstruct historical trends in Chesapeake Bay water quality, nutrients, dissolved oxygen, salinity, and other factors important to ecosystem functioning. USGS scientists are working with colleagues from the Maryland Geological Survey and University of Maryland to better understand the response of Bay ecosystems to human activities and natural climatic processes over years to decades and millennia. Chesapeake Bay Microorganisms found in Bay sediments. Representatives of these five groups commonly preserved in Chesapeake Bay sediments are shown in this figure.
Diatoms are algae that comprise the main photosynthetic group responsible for primary productivity.
Ostracodes are a group of Crustacea related to lobsters and crabs that also secrete a calcium carbonate shell. Dinoflagellates are marine and brackish water protists, referred to by various specialists as algae or protozoans, that are responsible for summertime blooms. Some dinoflagellate species have an encysting stage in their complex life cycle in which they form resistant cysts that settle in the Bay's sediment. A few of these species, like Pfiesteria piscicida , are believed to be responsible for causing fishkills and producing toxins that are also potentially harmful to humans who come in contact with the organism. Pollen grains carried into the Bay by rivers and air are common in Bay sediments and represent the major tree, shrub, and herb species in the Bay's surrounding watershed.