<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="SC-348" name="&lt;i&gt;Coquina&lt;/i&gt; Sand" parent="SC-322" scope="Substrate Group: Shell Sand that is primarily composed of broken down Coquina shells; this Sand has a characteristic orange color. Living clams may or may not be present; this is described in the BC."/><bt><term thcode="62" code="SC-322" name="Shell Sand" parent="SC-306" scope="Substrate Subclass: Biogenic Substrate layers that are dominated by Sand that is primarily composed of shell particles with a median particle size of 0.0625 millimeters to &lt; 2 millimeters (Sand). ..."/><term thcode="62" code="SC-306" name="Shell Substrate" parent="SC-301" scope="Substrate Class: Biogenic Substrate that is primarily composed of shells or shell particles. Most (but not all) shell-builders are mollusks."/><term thcode="62" code="SC-301" name="Biogenic Substrate" parent="SC-C003" scope="Substrate Origin: Substrates where percent cover of non-living Biogenic Substrate exceeds percent cover of both Geologic Substrate and Anthropogenic Substrates, when all are considered separately. ..."/><term thcode="62" code="SC-C003" name="Substrate" 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>