Biological relationships to convective flow patterns within stream beds

TitleBiological relationships to convective flow patterns within stream beds
Publication TypeJournal Article
Year of Publication1990
AuthorsWhite DS

Porewater flowlines in the bed of a small Michigan USA river were shown to be altered by Chara hummocks, sea lamprey nests, and beaver dams. Altered flow lines followed expected in-bed convective and underflow patterns predicted from published models. The greater density and shape of Chara hummocks caused upwellings into the hummocks, possibly being of benefit to the plants through contact with higher levels of dissolved substances contained in the cooler, deeper porewater. Streamwater downwelling into the more permeable sea lamprey nests may provide a continuous supply of well-oxygenated water, enhancing egg survival. Convective flow patterns beneath beaver dams, as well as beneath other bed surface features, may function to temporarily store dissolved streamwater substances, altering downstream transport rates, and may function to bring porewater/streamwater to the surface, affecting distributions of surface dwelling organisms.