Our rediscovery and interest in this original lifeform is no accident. It represents our need to return to the origins of life to understand and heal our planet. To begin with, it would be wonderful if we could contribute something as essential to Earth's life as oxygen. 6 Thousands of algal species cover the earth There may be more than 25,000 species of algae, living everywhere. They range in size from a single cell to giant kelp over 150 feet long.
Most algae live off sunlight through photosynthesis, but some live off organic matter like bacteria.
Larger algae, like seaweeds, are macroalgae. They already have an important economic role. About 70 species are used for food, food additives, animal feed, fertilizers and biochemicals. Microalgae can only be seen under a microscope. Some serve a vital role for breaking down sewage, improving soil structure and fertility and generating methane and fuels for energy.