<descriptor thcode="62"><thesaurus thcode="62" name="Coastal and Marine Ecological Classification Standard" scope="Categories of ecosystems for coastal, estuarine, and marine environments." creator="FGDC" rights="public domain" date="2017-05-10" codetype="alpha" prefix="cmecs" uri="https://www2.usgs.gov/science/CMECS" tblname="cmecs" root_code="root" contact="pschweitzer"><category><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/></category><altlabel><altlabel>CMECS</altlabel><altlabel>CMECS</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel></altlabel></thesaurus><term thcode="62" code="BC-411" name="Chrysophyte Phytoplankton" parent="BC-387" scope="Biotic Subclass: Waters dominated by Chrysophyte Phytoplankton, single-celled algae found mostly in freshwater (although several orders occur in brackish and salt water). ..."/><bt><term thcode="62" code="BC-387" name="Phytoplankton" parent="BC-384" scope="Biotic Class: This class includes areas of floating or suspended microscopic algae that are capable of photosynthesis. ..."/><term thcode="62" code="BC-384" name="Planktonic Biota" parent="BC-C002" scope="Biotic Setting: Planktonic Biota includes biota that drift, float, or remain suspended in the water column in aggregations that are big enough to be (a) detected by the human eye (or with mild magnification) or (b) sampled with a fine-plankton net. ..."/><term thcode="62" code="BC-C002" name="Biotic" parent="root"/><term thcode="62" code="root" name="CMECS" scope="Coastal and Marine Ecological Classification Standard: Category terms encompassing waters from the head of tide or inland incursion of ocean salinity to the splash zone of the coasts to the deepest portions of the oceans and the deep waters of the Great Lakes."/></bt><nt><term thcode="62" code="BC-468" name="Chrysophyte Aggregation" parent="BC-411" scope="Biotic Group: Waters dominated by chrysophytes; these cells can aggregate via mucus excretions that bind single cells into colonies, often combined with mineral particles and bacterial communities. ..."/><term thcode="62" code="BC-469" name="Chrysophyte Bloom" parent="BC-411" scope="Biotic Group: Surface waters where rapid growth and very high densities of chrysophytes occur. ..."/><term thcode="62" code="BC-470" name="Chrysophyte Maximum Layer" parent="BC-411" scope="Biotic Group: Relatively thin layer dominated by chrysophytes at depth in the water column; some chrysophytes are flagellated and can adjust their position in the water column. These and other plankton form maxima at depths where nutrients are in optimal concentrations."/></nt></descriptor>