<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="AS-007" name="Estuarine Coastal" parent="AS-002" scope="Subsystem: The Estuarine Coastal Subsystem extends from the supratidal zone at the land margin up to the 4 meter depth contour in waters that have salinity greater than 0.5 (during the period of average annual low flow). ..."/><bt><term thcode="62" code="AS-002" name="Estuarine" parent="AS-C000" scope="System: The Estuarine System is defined by salinity and geomorphology. ..."/><term thcode="62" code="AS-C000" name="Aquatic Setting" 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="AS-019" name="Estuarine Coastal Intertidal" parent="AS-007" scope="Tidal Zone: The substrate in this zone is regularly and periodically exposed and flooded by tides. This zone extends from MLLW to Mean Higher High Water (MHHW). The Coastal Intertidal is exposed regularly to the air by tidal action."/><term thcode="62" code="AS-018" name="Estuarine Coastal Subtidal" parent="AS-007" scope="Tidal Zone: The substrate is generally continuously submerged in this zone and includes those areas below MLLW."/><term thcode="62" code="AS-020" name="Estuarine Coastal Supratidal" parent="AS-007" scope="Tidal Zone: This zone includes areas above MHHW; areas in this zone are affected by wave splash and overwash. It does not include areas affected only by wind-driven spray, which may extend further inland."/></nt></descriptor>