Water Resources Research Act Program

Details for Project ID 2009PA103B

Developing Numeric Criteria to Guide Nutrient Controls for Streams in Pennsylvania

Institute: Pennsylvania
Year Established: 2009 Start Date: 2009-03-01 End Date: 2010-02-28
Total Federal Funds: $1 Total Non-Federal Funds: $2

Principal Investigators: Hunter Carrick, John Regan

Project Summary: Elevated material loading can be related to changing land-use (urban and agricultural practices), such that it has had a measurable effect on aquatic ecosystems throughout the mid-Atlantic region, where more than 2,500 miles of native stream receive some degree of impact in Pennsylvania alone. This project has been designed to assist the commonwealth of Pennsylvania in establishing numeric criteria simultaneously for nutrient uptake and storage (N, P) as well as chlorophyll. Our objectives will be met by carrying out a series of experiments using natural biofilms collected from streams of varying nutrient content and relative productivity. Biofilms will be sampled seasonally (winter, spring, summer, and fall) from streams already identified as having low, moderate, and high nutrient content within each of the two ecoregions (Appalachian Plateau and Piedmont) in the state's Water Quality Network. Rapid assays of P uptake by benthic biofilms (bacteria, fungi, algae) will be developed based upon techniques used for lake and oceanic ecosystems. P-utilization will be measured using uptake of radiolabelled, inorganic 33PO4, while uptake of organically-bound P will be measured from the activity of alkaline phosphatase (APA). We will investigate whether this biological transformation among phylogenic groups should be included in stream P models using a combination of molecular biological analyses. To evaluate if seasonal criteria are necessary and if ecoregion-specifc criteria are needed, spatio-temporal variation in uptake parameters will be evaluated using ANOVA, where ecoregion and season will be treated as fixed factors. Finally, the activity of the enzymes will be regressed against nutrient concentrations in the streams to assess the presence of a stream P threshold (y-intercept technique).