This is an interesting article about a study on how bio-diversity helps remove toxins in water. Cardinale’s study, which appears in the April 7 issue of Nature, was funded by the National Science Foundation.
The cleansing power of biodiversity
Scientists have long known that ecosystems that have more plant species tend to have a greater capacity to remove pollutants from soil and water than do ecosystems that have fewer species. But, until now, no one knew how or why this is so.
Cardinale’s study helps solve this mystery by explaining how biodiversity promotes the self-cleaning power of streams. According to the study, as algae grow in streams and produce more biomass, they incorporate into their bodies some common forms of pollution and thereby remove it from the water. Each species of pollution-removing algae has evolved and adapted to a different set of conditions, and so occupies a unique mini habitat, or niche, within a water body. Therefore, as the number of species of pollution-removing algae increases in a stream, so too does the number of unique niches that are occupied, filtered and cleansed by them. Hence: the more algae species a stream has, the more total pollutants these organisms may remove from the water.