Brown Algae, Phaeophyta, consist of many of the world’s seaweeds. There are approximately 1,500 species. Fucoxanthin is the pigment that makes the Brown Algae appear to be brown. With only a few exceptions, brown algae are marine, growing in the colder oceans in the world, many in the tidal zone, where they are subjected to great stress from wave action; others grow in deep water. Kelp is the largest of the seaweeds, which can grow over 100 ft in length. Fucus (rockweed), Sargassum (gulfweed), and the simple filamentous Ectocarpus are other examples of brown algae. They are economically important by being used as stabilizers in emulsions and are harvested all around the Pacific.

Some kelp conversing in a large group in the cold waters of the Pacific