The environment has always been a great interest of mine, & these four movements are supposed to give an impression of ocean life. Creatures at the edge of tides describes those crustaceans and small creatures who lead repetitive lives, dependant upon the ebb & flow of the tides. Dolphins describes the way the animals, leap, dive & play, and Whales gives an impression of whale song as they call to each other. Shimmering shoals gives an impression of the way shoals of fish suddenly change direction & their shining bodies can be seen from the surface.