<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="GC-184" name="Biogenic" parent="GC-C052" scope="Geoform Origin: Biogenic geoforms are physical features and landforms that were created by the action of living organisms (bioherms). ..."/><bt><term thcode="62" code="GC-C052" name="Geoform (levels 1 and 2 subcomponents)" parent="GC-C005"/><term thcode="62" code="GC-C005" name="Geoform" 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="GC-185" name="Atoll" parent="GC-184" scope="Geoform: A ring-like coral reef that nearly (or entirely) encloses a reef lagoon. ..."/><term thcode="62" code="GC-186" name="Burrows/Bioturbation" parent="GC-184" scope="Geoform: Tubes, holes, furrows, and small mounds formed by the digging, feeding, and movement of benthic fauna. These can bring nutrients and other compounds to the surface?as well as destabilize the substrate."/><term thcode="62" code="GC-190" name="Coral Reef Island" parent="GC-184" scope="Geoform: A tropical island built of organic material derived from the skeletons of corals and other reef associates. ..."/><term thcode="62" code="GC-196" name="Deep/Cold-Water Coral Reef" parent="GC-184" scope="Geoform: Reefs formed by deepwater azooxanthellate (i.e., lacking symbiotic algae), stony corals (Order Scleractinia). ..."/><term thcode="62" code="GC-191" name="Mollusk Reef" parent="GC-184" scope="Geoform: An area of many shell reefs surrounded and intermixed with channels and unvegetated flats."/><term thcode="62" code="GC-199" name="Shallow/Mesophotic Coral Reef" parent="GC-184" scope="Geoform: Light-dependent coral reefs that occur within the photic zone (the mesophotic reefs occur in the lower part of this zone at depths of 30 - 150 meters). (http://www.mesophotic.org)."/><term thcode="62" code="GC-212" name="Tree Fall" parent="GC-184" scope="Geoform: Tree falls are trees or woody parts that have sunk to the deep ocean floor (generally 2,000 meters or deeper) and may remain there for decades. ..."/><term thcode="62" code="GC-213" name="Whale Fall" parent="GC-184" scope="Geoform: Whale carcasses that have fallen to the deep ocean floor (generally 2,000 meters or deeper), and which support a wide variety of arthropods and worms?and a limited number of fish. Whale falls can persist for decades (see Figure 6.9)."/><term thcode="62" code="GC-214" name="Worm Reef" parent="GC-184" scope="Geoform: Reefs that consist of the consolidated tubes of many individual tube worms, often of the sabellaria and serpulid genera. They may be calcareous or siliceous, and the outer surface of these reefs may support living worm communities."/></nt></descriptor>