Kelp forests are located all throughout the world. Right here in the United States, we have kelp forests on both the west and east coasts. They are mostly located in California and Alaska. Kelp Forests form in cold, nutrient-rich water. Other than coral reefs, kelp forests are one of the most biodiverse marine habitats. They are found in cold, shallow waters along the coast. They are dependent on light because they require photosynthesis to receive their energy. Two "keystone species" of kelp forests are sea otters and sea urchins. Kelp is known for its rapid growth. Urchins graze and help maintain the plant. Sea otters use the long plants to hide from their prey. Kelp forests are vital to marine life.