Kelp Forests

Underwater forests formed by dense stands of large brown algae, most famously giant kelp, which anchors to the seafloor and grows toward the surface at rates that can exceed half a meter a day, among the fastest growth of any organism on Earth. Found along cold, nutrient rich coastlines on every continent but Antarctica, from the Pacific coast of North America to the shores of South Africa, Australia and Chile, kelp forests rank among the most productive ecosystems on the planet, sheltering fish, invertebrates and marine mammals within their canopy. The system depends on a delicate balance of predators and grazers, most famously sea otters, whose decline can let sea urchin populations explode and strip a kelp forest down to bare rock, a collapsed state known as an urchin barren.