Water Resources Research Act Program

Details for Project ID 2015AR370B

Relationship between nutrients, macrograzers abundance (Central Stonerollers and Crayfish), and algae in Ozark Streams.

Institute: Arkansas
Year Established: 2015 Start Date: 2015-03-01 End Date: 2016-02-29
Total Federal Funds: $5,000 Total Non-Federal Funds: $10,000

Principal Investigators: Michelle Evans-White, Jefferson Scott

Abstract: Elevated nitrogen (N) and phosphorous (P) in streams can cause nutrient pollution leading to instream and downstream problems of excess algal growth which can constrain the recreational use of streams and reduce stream biodiversity. States are charged with the task of setting regional nutrient criteria standards based on scientific methods which can include the assessment of algal biomass. Local studies have suggested that nutrients can be a determining factor of algal biomass in Ozark Highland streams and have suggested that algal growth is limited by N in Ozark streams. Grazers can have significant impacts on algal biomass and may reduce the variability in algal biomass explained by nutrient concentrations. Specifically, algal grazing by stonerollers (Campostoma spp.) and crayfish (Orconectes spp.) can be important determining factors on algal biomass in Ozarks streams and could explain some existing variation in algal biomass across streams with varying nutrient concentrations. The results from this study will be used to better define the link between stream nutrient concentrations and algal biomass in Ozark Highland northern Arkansas wadeable streams. Specifically, I propose to test the strength of top-down controls of stonerollers and crayfish on algae across a nutrient gradient in Ozark streams. The results of this research may be considered when determining regional nutrient thresholds and the establishment of regional nutrient criteria in Arkansas.