There are 50 breeding pairs of common shelducks Ingold, P (1991) Competition for feeding areas and dominance relationships among shelducks Tadorna tadorna with broods, (1991) Ornis Scand 22 (1): 27-32 in the estuary, and there is a mixed tern breeding colony on the east shore 1.0 kilometers from the mouth comprising Arctic, Sandwich, little and common terns.