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Varieties of Seaweed

Seaweed tends to dominate intertidal ocean areas that are rocky. In particular seaweed grows in polar and temperate regions. Normally seaweed grows in 26 to 132 feet of water, though in warmer climates with very clear water it can be found as deep as 800 feet down. Seaweed has many uses; food, production of biofuels, cosmetic applications, organic fertilizers, energy collectors and more.

Red Seaweed
- This group's red appearance is due to two pigments, phycocyanin and phycoerythrin, that mask the green and brown pigments. More than 6,000 red seaweed species have been identified around the world, though the most common are Gigartinaceae and Corallinaceae. One type of red seaweed, Corallinaceae, is used in bone replacement therapies. Corallina secretes the bone material calcium carbonate over the surface of their cells. Carrageen moss and Dulse are used in cooking. Betaphycus and Kappaphycus red seaweed are the main source of the food additive carrageenan, which is an ingredient in many food products. Agar, which is used for scientific applications, is extracted from Pterocladia, Gelidium and Gracilaria.
Brown Seaweed
- Brown seaweed do not have unicellular species. The most basic type of brown seaweed are large-branched kelps. Some kelps can be as large as 70 meters, or nearly 230 feet. This type of seaweed is the only one to have internal tissue differentiation, like plant xylem. The xylem in plant is a vascular system that transports water throughout the plant. As with red seaweed, the color of brown seaweed is due to the pigment fucoxanthin. This pigment masks all other pigments in the seaweed. The largest of the approximately 1,800 brown seaweed species are found in very cold water. Laminaria hyperborea is used to make high-grade alginates. Ascophyllum nodosum is processed to produce alginic acid. Alginate and alginic acid are emulsifiers used in gum, dyes and food products. Other species of brown seaweed are used as liquid seaweed extracts for agricultural sprays.
Green Seaweed
- The color of green seaweed is due to high levels of chlorophyll a and b. These seaweeds can be multicellular, unicellular, living in colonies or made of one cell that has many cross walls with multiple nuclei. Green seaweed is found in water but can also grow on trees and soil. Some species even live on animals in a symbiotic relationship. Dunaliella salina is grown commercially in Australia for beta carotene. Chlorella is used as a seaweed supplement and food additive.

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