New publication from Graham Lab

about Lake Mendota algae

American Journal of Botany coverPeople sometimes complain about green growths of algae that occur on the rocky shorelines of Lake Mendota and similar places around the world. Cladophora, a native green alga large enough to see without a microscope, often dominates such shoreline communities, known as periphyton. The abundance of periphyton is proportional to the amount of phosphorus and other mineral nutrients present in the water, and since Lake Mendota waters are high in phosphorus as the result of human impacts, Cladophora is more abundant than it would be in waters having lower phosphorus levels.

In the latest issue of The American Journal of Botany, the Graham lab revealed that Cladophora, together with a host of bacteria that naturally grow on its surfaces actually provide beneficial ecological services. The lab used state-of-the-art sequencing methods to identify about 100 bacteria from amongst many more that live on Lake Mendota Cladophora. Despite an intensive search, no harmful bacteria were identified, whereas many types of beneficial species occurred. Benefits include the ability of periphyton communities to absorb and store phosphorus, thereby reducing the amount of this nutrient that is available to harmful floating cyanobacteria (blue-grreen algae). The team also found evidence that periphyton reduces the amount of methane that bubbles up from the lake bottom, preventing this powerful greenhouse gas from entering Earth’s atmosphere.

Because Cladophora occurs in fresh and marine waters worldwide, this alga exerts these and other beneficial effects on a global basis. The Graham lab is working with an international team of researchers to apply the beneficial traits of Cladophora to the solution of pressing environmental problems.