Water Resources Research Act Program

Details for Project ID 2016NC202B

How, where, when, and why: Defining Eutrophication Related Trends in Water Quality for the Middle and Lower Cape

Institute: North Carolina
Year Established: 2016 Start Date: 2016-03-01 End Date: 2017-02-28
Total Federal Funds: $10,000 Total Non-Federal Funds: $47,654

Principal Investigators: Nathan Hall, Hans Paerl

Abstract: Over the past decade, the Cape Fear River, NC has experienced symptoms of eutrophication that threaten its value as a vital natural resource for recreation, aquatic habitat, and water supply. While there is a perception that water quality is deteriorating and that increased anthropogenic nutrient loading is likely responsible, very few trend analyses for eutrophication-related water quality parameters have been conducted. This project will leverage an expansive, multi-decade water quality dataset collected by NCDENR, the Middle Cape Fear River Basin Association, and the Lower Cape Fear River Project. Statistically robust trend analyses will be conducted at nineteen sites distributed throughout the middle and lower Cape Fear basin for concentrations and fluxes of eutrophication related water quality parameters including nutrients, chlorophyll a, dissolved oxygen, pH, total suspended sediments, and water clarity. The objectives are to determine how conditions have changed, where in the basin, and when in the data records are changes most apparent. Additionally, a recently developed weighted regression modeling approach will be used to determine shifts in seasonality and shifts in relationships of water quality constituents with flow. Such shifts in combination with information on anthropogenic activities in the watershed (i.e. changes in point/non-point sources) will be used to identify likely reasons why water quality has changed. Information gained will provide a broad ecosystem-level characterization of human and climatic influences on water quality over the past 2-4 decades. Determining where water quality is deteriorating or improving, and why will help prioritize management plans and allow for targeted management responses to specific sources of pollution. This information will be greatly needed as NCDENR updates the Cape Fear River Basinwide Water Quality Plan. By establishing historic baseline conditions and water quality trajectories, the project will be of immediate benefit to recently initiated efforts to develop realistic and achievable nutrient targets under the Nutrient Criteria Development Plan. A two day workshop will teach the recently developed modeling technique to NCDENR staff, stakeholder groups, and fellow researchers for use throughout NC surface waters.