Kelp Forest

A kelp forest is a marine biome of dense underwater stands formed by large, fast-growing brown algae of the order Laminariales, rooted to rocky seafloor by holdfasts and reaching toward the surface on gas-filled blades that can grow more than thirty centimetres a day under good conditions. Kelp forests occur in cold, nutrient-rich temperate and polar coastal waters, most famously along the Pacific coasts of North America and the coasts of South Africa, Australia and New Zealand, and their three-dimensional canopy shelters fish, invertebrates and marine mammals in a structure often compared to a forest on land. The biome depends on grazing pressure staying in balance, since sea urchins left unchecked by predators such as sea otters can strip a kelp forest to bare rock in what ecologists call an urchin barren.