Water Resources Research Act Program

Details for Project ID 2011OH207B

Does Alum Addition Affect Benthic Communities and Metal and Nutrient Cycling? A Case Study from Grand Lake St. Marys, Ohio

Institute: Ohio
Year Established: 2011 Start Date: 2011-03-01 End Date: 2012-02-29
Total Federal Funds: $29,695 Total Non-Federal Funds: $60,987

Principal Investigators: Chad Hammerschmidt, Amy Burgin, Geraldine Nogaro

Abstract: Excessive nutrient loadings to water bodies can result in eutrophication, a process associated with increased primary production and simplification of biodiversity. Subsequent decomposition of the produced biomass results in depleted levels of dissolved oxygen, and, in the case of Grand Lake Saint Marys (GLSM), high loadings of phosphorus have promoted blooms of toxic, nitrogen-fixing cyanobacteria. These consequences of eutrophication can be harmful ecologically and impact human use of the resource. Multiple options are being considered currently to reduce external and internal nutrient loadings to GLSM. Addition of aluminum sulfate (alum) to GLSM has been proposed by the OH EPA and the OH Department of Agriculture (DoA), together with the environmental consulting group TetraTech, as a short-term treatment to decrease P levels and combat the harmful algal blooms. While alum has been used previously in other lakes, the ecological effects of alum treatment on benthic microbial and invertebrate communities are still poorly understood. In September 2010, the OH EPA conducted a pilot study to examine the efficacy of alum additions on planktonic growth in three small bays of GLSM. We propose to use these alum test locations, with matched reference sites, to investigate the effects of alum treatment on: 1) metal and nutrient cycling in surface waters and sediments and 2) microbial and macrofaunal communities in lake sediments. This research should provide a preliminary indication of whether alum additions to GLSM have any short-term adverse effects on benthic communities as well as trace metal and nutrient cycles.