Foam and bubbles float on the surface of water in the North Esk river in Scotland which slowly laps against the edges of a muddy river bank while a fast-flowing river flows past in the background

river bank stream fresh water river flowing ripple whitewater water fastflowing froth tide surface turbulent spume churn moss pollution shallow flow foam foamy surge lapping carbon shifting float cliff foaming movement cold fishing contrast floating circulate bubbles patterns salmon whirl swirl change drift bubble twist white fast current black eddy lap