Oceans dominate the world's weather systems while supporting a wide range of life.
Mountain ranges, perpetual night, pressure and temperature extremes create unusual life forms.
Half-moon fish; loggerhead turtles; schools of sardines and tuna; vastness of the ocean.
Life on the edge of frozen seas near the North and South poles.
Plankton use sunlight as an energy source in temperate-sea habitats.
Predators utilize marshes created by tides; finback and humpback whales; sand crabs; surfing snails; dolphins.
Breeding forces animals to come onto land; eagles; marine iguana; Olive Ridley turtles; killer whales hunt sea lion pups; rockhopper penguins.