Estuarine waters are understood to be those water masses which by virtue of their position are directly subject to the combined action of river and tidal currents. They may be considered to reflect certain dominant forces as well as progressive trends that determine their individualistic though changing hydrographic as well as biologic properties. The factors that lend individuality to these bodies may exhibit profound differences in different latitudes and yet, in certain fundamental respects, the waters possess important characteristics in common....