Tides govern marine life. Tidal marshes are one of the most productive parts of the world. Numerous plants support numerous animals, yet life is not easy: predators are attracted to these enormous quantities of food, forcing animals to seek constant protection from attack. Relief comes with the crashing waves, as the tides flow once more. Between the tides, when the sands become depleted of food and air, the worms, clams and shrimps just endure the expected pause.