<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-547" name="Stromatolites" parent="BC-428" scope="Biotic Group: Areas dominated by large, mound-like formations built up in shallow marine areas by secretions of cyanobacteria, which further entrap minerals and sediment. They form Earth's oldest fossils and originated over 3 billion years ago."/><bt><term thcode="62" code="BC-428" name="Structure Forming Microbes" parent="BC-392" scope="Biotic Subclass: Areas dominated by microbes that form a hard structure, generally through secretions and entrapment of minerals and sediments."/><term thcode="62" code="BC-392" name="Microbial Communities" parent="BC-389" scope="Biotic Class: Areas dominated by colonies of microscopic or single-celled organisms that form a hard structure, visible film, layer, or mat on or near the surface of the substrate. ..."/><term thcode="62" code="BC-389" name="Benthic/Attached Biota" parent="BC-C002" scope="Biotic Setting: This biotic setting describes areas where biota lives on, in, or in close association with the seafloor or other substrates (e.g., pilings, buoys), extending down into the sediment to include the sub-surface layers of substrate that contain multi-cellular life. ..."/><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></descriptor>