Bubbles of foam floating on the surface of water in the river North Esk swirl together to form a constantly changing pattern where the faster current meets a still section of water

ripple dissolved organic carbon water foam pollution flowing foamy stream spume froth fresh water turbulent surface swirling river whitewater bubbles carbon churn foaming float river esk bubble north esk flow swirl floating shifting surge circulate detergents movement spiral change patterns drift contrast twist fishing dark whirl shapes black eddy current salmon fast white organic