Life in the World's Oceans. Episode 4, Beaches, Estuaries, and Coral ReefsLife in the World's Oceans. Episode 4, Beaches, Estuaries, and Coral Reefs

Beach organisms exist with the constantly changing winds, waves, and tides (sometimes underwater, sometimes fully exposed to the air). Life in estuaries, where rivers meet the oceans, face constant fluctuations in environmental salinity. And hard corals are continually pummeled by wave action. Yet each of these physically…