Ecology of Phaeophyta
Phaeophyta make up a wide variety of niches that include tidal splash zones, rock pools, intertidal zones, and relatively deep near shore waters. Phaeophyta use the sun to convert water and carbon dioxide into sugars and amino acids. Many organisms benefit from the nutrients that they give off, and they are eaten by a variety of fish and sea urchins. Their uses include food thickeners, stabilizers, and fillers. Kelp is also great as fertilizers. Many phaeophyta are used in the manufacturing of soaps, paints, toothpastes, lipsticks, medicines, stabilizers in food products, and in the production of beer.
http://marinelife.about.com/od/plants/p/brownalgae.htm
http://www.ehow.com/about_6628173_phaeophyta-life-cycle.html
http://www.ehow.com/about_6628173_phaeophyta-life-cycle.html