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Freshwater unionid bivalves are spatially and temporally distributed throughout the Morrison depositional basin, and locally dominate the biomass of many aquatic depositional environments. Two bivalve assemblages are identified. Within-channel assemblages are death assemblages that have been transported and may represent mixed assemblages from multiple communities. These assemblages are predominately disarticulated, in current stable orientations, and composed of higher stream velocity ecophenotypes (medium size, lanceolate form, and very thick shells). The floodplain-pond assemblages are disturbed neighborhood assemblages in the mudstones inhabited during life. The bivalves are predominately articulated, variable...
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Camarotoechia, atrypa, atrypella and carchidium-conchidium Alaska. Plate 8 in U.S. Geological Survey. Professional paper 233-C. 1952.
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This map was created to help assess impacts on nonindigenous aquatic species distributions due to flooding associated with Hurricane Maria. Storm surge and flood events can assist expansion and distribution of nonindigenous aquatic species through the connection of adjacent watersheds, backflow of water upstream of impoundments, increased downstream flow, and creation of freshwater bridges along coastal regions. This map will help natural resource managers determine potential new locations for individual species, or to develop a watch list of potential new species within a watershed. These data include a subset of data from the Nonindigenous Aquatic Species Database, that fall within the general area of the 2017...


map background search result map search result map Nonindigenous aquatic species and potential spread after Hurricane Maria Nonindigenous aquatic species and potential spread after Hurricane Maria