<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-426" name="Soft Sediment Fauna" parent="BC-391" scope="Biotic Subclass: Areas that are characterized by fine unconsolidated substrates (sand, mud) and that are dominated in percent cover or in estimated biomass by infauna, sessile epifauna, mobile epifauna, mobile fauna that create semi-permanent burrows as homes, or by structures or evidence associated with these fauna (e.g., tilefish burrows, lobster burrows). ..."/><bt><term thcode="62" code="BC-391" name="Faunal Bed" parent="BC-389" scope="Biotic Class: Seabeds dominated or characterized by a cover of animals that are closely associated with the bottom, including attached, clinging, sessile, infaunal, burrowing, laying, interstitial, and slow-moving animals, but not animals that have created substrate (Reef Biota). ..."/><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><nt><term thcode="62" code="BC-1220" name="Brachiopod Bed" parent="BC-426" scope="Biotic Group: Soft-sediment areas dominated by burrowing, clam-like brachiopods, a phylum of animals with two shells, a stalk-like peduncle, and a tentacular, ciliated feeding organ. ..."/><term thcode="62" code="BC-520" name="Burrowing Anemones" parent="BC-426" scope="Biotic Group: Areas dominated by anemones (solitary coelenterates) that use their pedal disc to burrow in soft substrates. ..."/><term thcode="62" code="BC-542" name="Burrowing Urchins" parent="BC-426" scope="Biotic Group: Assemblages dominated by burrowing, &quot;irregular&quot; echinoids (e.g., burrowing urchins, heart urchins). These flattened urchins typically live underneath the sediment surface and feed on mud or on particles of detritus."/><term thcode="62" code="BC-1284" name="Cephalochordates" parent="BC-426" scope="Biotic Group: Soft-sediment areas (typically sandy) that are dominated by the rapidly burrowing, fish-like Amphioxus, or by other similar Genera of the subphylum Cephalochordata, a group of animals with characteristics of both vertebrates and invertebrates. ..."/><term thcode="62" code="BC-524" name="Clam Bed" parent="BC-426" scope="Biotic Group: Areas where either: (a) living clams, siphons, or siphon holes are the dominant surface feature, or; (b) clams dominate the faunal biomass. ..."/><term thcode="62" code="BC-527" name="Diverse Soft Sediment Epifauna" parent="BC-426" scope="Biotic Group: Highly varied and diverse communities of mixed fauna that are present on the surface of soft unconsolidated substrates. ..."/><term thcode="62" code="BC-528" name="Echiurid Bed" parent="BC-426" scope="Biotic Group: Soft-sediment areas dominated by unsegmented echiurids or &quot;spoon worms&quot; which are abundant on the U.S. ..."/><term thcode="62" code="BC-530" name="Holothurian Bed" parent="BC-426" scope="Biotic Group: Soft sediment assemblages dominated by holothurians or &quot;sea cucumbers&quot;, which are common in both shallow and deep areas of the ocean. ..."/><term thcode="62" code="BC-531" name="Hydroid Bed" parent="BC-426" scope="Biotic Group: Areas dominated by hydroid species that are not attached to a hard substrate. ..."/><term thcode="62" code="BC-521" name="Larger Deep-Burrowing Fauna" parent="BC-426" scope="Biotic Group: Assemblages dominated by the presence?or evidence?of larger, deep-burrowing, soft-bodied, generally worm-like infauna. ..."/><term thcode="62" code="BC-538" name="Larger Tube-Building Fauna" parent="BC-426" scope="Biotic Group: Soft sediment areas dominated by larger tube builders (tube width &gt; 2 millimeters, or tube length &gt; 30 millimeters), most commonly polychaetes, but including many other worm-like phyla (phoronids, sipunculids), crustaceans, and others. ..."/><term thcode="62" code="BC-526" name="Mobile Crustaceans on Soft Sediments" parent="BC-426" scope="Biotic Group: Areas where the epifaunal or surface community is dominated by slow-moving crustaceans. ..."/><term thcode="62" code="BC-1222" name="Mobile Mollusks on Soft Sediments" parent="BC-426" scope="Biotic Group: Areas dominated by epifaunal, slow-moving, generally detritivorous, herbivorous, or omnivorous gastropods, scaphopods, or other mollusks foraging at the surface of unconsolidated sediments. ..."/><term thcode="62" code="BC-532" name="Mussel Bed" parent="BC-426" scope="Biotic Group: Soft-sediment areas dominated by mussel species that are not attached to a hard substrate. ..."/><term thcode="62" code="BC-543" name="Oligozoic Biota" parent="BC-426" scope="Biotic Group: Zones that are devoid of macrofauna, larger fauna, and microbial mats, i.e., where no evidence of larger multicellular life can be detected when a sufficient area of the substrate is sampled to deliver sub-millimeter resolution, and where microbial communities are not visible to the naked eye. ..."/><term thcode="62" code="BC-534" name="Oyster Bed" parent="BC-426" scope="Biotic Group: Soft-sediment areas dominated by oyster species that are not attached to a hard substrate and are not present in densities sufficient to construct substrate. ..."/><term thcode="62" code="BC-537" name="Pennatulid Bed" parent="BC-426" scope="Biotic Group: Subtidal soft-bottom habitats that are dominated by sea pens or sea pansies (Phylum Cnidaria, Order Pennatulacea). ..."/><term thcode="62" code="BC-535" name="Sand Dollar Bed" parent="BC-426" scope="Biotic Group: Assemblages dominated by surface-dwelling, &quot;irregular&quot; echinoids of the Phylum Echinodermata and Order Clypeasteroida (e.g., sand dollars, sea biscuits). ..."/><term thcode="62" code="BC-536" name="Scallop Bed" parent="BC-426" scope="Biotic Group: Areas dominated by accumulations of scallops. ..."/><term thcode="62" code="BC-1225" name="Sea Urchin Bed" parent="BC-426" scope="Biotic Group: Sandy or muddy areas dominated by &quot;regular&quot; echinoids (e.g., sea urchins). These rounded urchins typically live on top of the sediment surface, and several species are well adapted to life on soft sediments, occurring in great numbers in certain locations."/><term thcode="62" code="BC-522" name="Small Surface-Burrowing Fauna" parent="BC-426" scope="Biotic Group: Areas dominated by small, burrowing, often worm-like fauna with a body width usually &lt; 2 millimeters; animals are typically found within 5 centimeters of the sediment-water interface. ..."/><term thcode="62" code="BC-539" name="Small Tube-Building Fauna" parent="BC-426" scope="Biotic Group: Soft sediment areas dominated by tube-building annelids (e.g., spionids, sabellids), amphipods, small phoronids, or other small, surface-dwelling, tube-building fauna. ..."/><term thcode="62" code="BC-1283" name="Soft Sediment Basket Stars" parent="BC-426" scope="Biotic Group: Sandy or muddy areas characterized by brushy, many-armed echinoderms known as basket stars. ..."/><term thcode="62" code="BC-1221" name="Soft Sediment Brittle Stars" parent="BC-426" scope="Biotic Group: Fine substrate assemblages dominated by crawling, burrowing or infaunal brittle stars, which are a relatively mobile class of echinoderms. ..."/><term thcode="62" code="BC-523" name="Soft Sediment Bryozoans" parent="BC-426" scope="Biotic Group: Areas dominated by bryozoans (small colonial filter-feeding animals with a calcareous skeleton) that may grow in complex branched structures, bushy shapes, or other forms). ..."/><term thcode="62" code="BC-525" name="Soft Sediment Crinoids" parent="BC-426" scope="Biotic Group: Areas dominated by crinoid species that are not attached to a hard substrate. ..."/><term thcode="62" code="BC-1223" name="Sponge Bed" parent="BC-426" scope="Biotic Group: Sandy or muddy areas of the seafloor that are dominated by sponges and their associated communities, but do not create substrate such that they would be considered Reef Biota. ..."/><term thcode="62" code="BC-1224" name="Starfish Bed" parent="BC-426" scope="Biotic Group: Soft sediment areas in which starfish occur in large aggregations and clearly dominate the biota. ..."/><term thcode="62" code="BC-540" name="Tunicate Bed" parent="BC-426" scope="Biotic Group: Sandy or muddy areas dominated by members of the subphylum Urochordata, including ascidians, sea squirts, and other tunicates. ..."/><term thcode="62" code="BC-541" name="Tunneling Megafauna" parent="BC-426" scope="Biotic Group: Intertidal or Subtidal areas dominated by burrowing or construction activities of larger (megafaunal) organisms that create a water-filled tunnel with a diameter of &gt; 1 centimeter. ..."/></nt></descriptor>