Bubbles of foam in focus in the foreground float on the surface of a Scottish river and slowly lap against the river bank while a fast-flowing river rushes past a moss covered cliff in the background

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