Sea kelp is a type of large, brown seaweed that grows in underwater forests in shallow ocean waters. It thrives in nutrient-rich environments and can grow up to 200 feet long. Kelp provides habitat and food for various marine species, including fish and invertebrates. Kelp is also important for humans, as it is used in various products, such as food, cosmetics, and fertilizers. It is rich in vitamins and minerals, making it a popular ingredient in health supplements. Additionally, kelp forests help absorb carbon dioxide, playing a role in combating climate change.