This giant kelp was photographed in Channel Islands National Marine Sanctuary, but giant kelp is found all the way from southeast Alaska to Baja California, and also in Peru, Chile, Argentina, Tasmania and New Zealand! This macroalga grows to about 30 meters in height, though can grow to more than 50 meters in ideal conditions. Because it frequently grows in dense kelp forests, giant kelp provides essential shelter for many species of adult fish and serves as a nursery for juveniles. In California, up to 100 species of fish depend on these forests!
Macrocystis pyrifera is in the family Laminariaceae. Commonly known as giant kelp, it is found along the coasts of the Pacific Northwest, South America, and Australasia. It is a common misconception that giant kelp is a species of plant. In fact, it is a brown algae, very distantly related to plants and even green algae. However, giant kelp and other brown algae still have the capacity to photosynthesize due to an evolutionary event independent from rise of photosynthesis in plants. Giant kelp is the largest species of brown algae, and is even considered one of the fastest growing organisms on the planet. Giant kelp can form dense populations underwater known as kelp forests, which harbor hundreds of different species of aquatic life. Under the right conditions, giant kelp can grow up to 2 feet a day, reaching an ultimate height of over 150 feet tall.
Happy Arbor Day! National marine sanctuaries may not have trees, but they do have kelp forests that serve as crucial habitats for many marine animals. Nancy Foster Scholar alumna Nyssa Silbiger snapped this amazing photo of giant kelp (Macrocystis pyrifera) in Monterey Bay National Marine Sanctuary.