High diversity within the periphyton community of an algal turf scrubber on the Susquehanna River

Authors: KANGAS, PATRICK - University Of Maryland; Mulbry, Walter; KLAVON, PHILIP - University Of Maryland; LAUGHINGHOUSE, DAIL - Smithsonian Institute; ADEY, WALTER - Smithsonian Institute

Submitted to: Ecological Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/5/2017
Publication Date: 5/19/2017
Citation: Kangas, P., Mulbry III, W.W., Klavon, P., Laughinghouse, D., Adey, W. 2017. High diversity within the periphyton community of an algal turf scrubber on the Susquehanna River. Ecological Engineering. 108:564-572.

Interpretive Summary: Restoration of the Chesapeake Bay poses significant challenges because of increasing population pressure, conversion of farmland to urban/suburban development, and the expense of infrastructure needed to achieve significant and sustained nutrient reductions from agricultural and urban sources. One approach that is being evaluated for removing non-point source nutrients before they reach the Chesapeake Bay is the deployment of algal turf scrubbers (ATS) along its tributaries and/or drainage canals. In ATS systems, algae grow on nutrients in the water and are harvested for potential use as a fertilizer or soil amendment. Although a variety of ATS sytems have been characterized with respect to their nutrient removal rates, very little is known about the underlying algal community. As part of a project using a pilot-scale ATS adjacent to the Susquehanna River, we characterized the algal community over an 18 month period. Results show high species diversity within the scrubber (over 130 algae species within the 28 square meter growing surface). ATS systems have been recommended for inclusion as a best management practice within the Chesapeake Bay Program Watershed Model. These results are important for this evaluation because they begin to define and characterize the consortia of algae and microorganisms responsible for growth of the algal turf and nutrient uptake. This information will be useful to scientists.

Technical Abstract: Algal turf scrubber systems have been evaluated for their ability to remove dissolved nutrients from a variety of natural waters and agricultural wastewaters. Although these systems have been well characterized with respect to productivity and nutrient removal, very little is known about the community structure and population dynamics of the underlying algal community. As part of a project using a pilot-scale algal turf scrubber adjacent to the Susquehanna River, we characterized the periphyton community over an 18 month period. Results show high species diversity within the scrubber (136 species within the 28 square meter growing surface). High diversity is likely due to a combination of factors: species diversity in the source community (the Susquehanna River), spatial heterogeneity of the ATS system, and vertical structure of the turf community.