Steven Rier

Teaching

• Freshwater Ecology
• Freshwater Entomology
• Algae of Freshwater Ecosystems
• Global Change Biology
• Analysis and Communication of Biological Data
• Ecology laboratory
• Microbiology laboratory
• Freshman Biology laboratories

Research Interests

• Stream Ecology
• Algal and Microbial Ecology
• Water Pollution

Selected Publications

• Rier, S.T., B. Gonzales, M. Hurley, T. Dapkey and S. Kroll. 2025. Combining assessments of periphyton structure and function to detect subtle anthropogenic impacts to headwater streams in the upper Delaware Basin, USA. Hydrobiologia 852:505-526.
• Pan, Y., S.T. Rier, K. Manoylov. 2025. Preface: Advances in freshwater algal ecology. Hydrobiologia 852: 502-504.
• Liddick, M., S.T. Rier. 2025. The entrainment of polyester microfibers modifies the structure and function of periphytic biofilms. Hydrobiologia 852:545-560.
• Ashberry, E.L. Rier, S.T., Halvorson, H.M., and K.A. Kuehn. 2021. Algal-driven priming of cellulose decomposition along a phosphorus gradient in stream mesocosms. Freshwater Science: 40: 580-592.
• Rier, S.T., K.C. Kinek, S.E. Hay and S.N. Francoeur. 2016. Polyphosphate plays a vital role in the phosphorus dynamics of stream periphyton. Freshwater Science 35:490-502.
• Rier, S.T., J. M. Shirvinski and K. C. Kinek. 2014. In-situ light and phosphorus manipulations reveal potential role of biofilm algae in enhancing enzyme-mediated decomposition of organic matter in streams. Freshwater Biology 59:1039-1051.
• 30 Authors including S.T. Rier. 2014. US EPA Expert Workshop: Nutrient Enrichment Indicators in Streams. Environmental Protection Agency, Office of Water. Washington, D.C.
• Francoeur, S. N., S. T. Rier, and S. B. Whorley. 2013. Methods for Sampling and Analyzing Wetland Algae. Pages 1-58 in J. T. Anderson and C. A. Davis, editors. Wetland Techniques: Volume 2: Organisms. Springer, The Netherlands
• Bott, T., J. Jackson, M. McTammany, J. Newbold, S. Rier, B. Sweeney, and J. Battle. 2012. Abandoned coal mine drainage and its remediation: Impacts on stream ecosystem structure and function. Ecological Applications 22:2144-2163.
• Rier, S. T., K.S. Nawrocki, and J.C. Whitley. 2011. Response of biofilm extracellular enzymes along a stream nutrient enrichment gradient in an agricultural region of North Central Pennsylvania, USA. Hydrobiologia 669:119-131.

Recent Grants

• Factors influencing temperature and flow stability in the Headwater streams of the upper Delaware watershed and potential consequences for genetic biodiversity and ecosystem function. National Fish and Wildlife Federation, in collaboration with The Academy of Natural Sciences of Drexel University ($84,043, CU budget).
• Evaluating Headwater Biodiversity, Vulnerability, and Potential Resilience to Inform Conservation in the Delaware Basin, National Fish and Wildlife Federation, in collaboration with The Academy of Natural Sciences of Drexel University ($43,912, CU budget)
• Evaluating the climate resilience of headwaters and potential downstream effects. PA DEP Growing Greener, in collaboration with The Academy of Natural Sciences of Drexel University, pending ($37,704, CU Budget)
• Measuring performance of best management practices installed as part of the implementing precision conservation in the Susquehanna River Watershed. National Fish and Wildlife Federation ($115,000, CU budget)

Rier Laboratory Webpage