Abstract
The authors find no arguments that would justify application of the term "estuary" to the area of the Odra River discharge into the Baltic Sea. The physiography, geology, and hydrology of the Odra river mouth show that the area possesses many more characteristics typical of flow-through coastal lagoons than those of estuaries. Of key importance in this respect is the Szczecin Lagoon, an extensive, shallow water body separated from the open sea by a barrier intersected by three narrow and long straits. The lagoonal nature of the area is demonstrated also by its geological history.