2000 Progress Report: The Choptank River: A Mid-Chesapeake Bay Index Site for Evaluating Ecosystems Responses to Nutrient ManagementEPA Grant Number: R826941
Title: The Choptank River: A Mid-Chesapeake Bay Index Site for Evaluating Ecosystems Responses to Nutrient Management
Investigators: Malone, Thomas C. , Boicourt, William C. , Cornwell, Jeffrey C. , Harding Jr., Lawrence W. , Stevenson, J. Court
Institution: University of Maryland Center for Environmental Science , Horn Point Laboratory
Current Institution: Horn Point Laboratory
EPA Project Officer: Packard, Benjamin H
Project Period: September 15, 1998 through September 14, 2001 (Extended to September 14, 2002)
Project Period Covered by this Report: September 15, 1999 through September 14, 2000
Project Amount: $596,097
RFA: Ecological Effects of Environmental Stressors Using Coastal Intensive Sites (1998) RFA Text | Recipients Lists
Research Category: Ecosystems , Ecological Indicators/Assessment/Restoration , Environmental Statistics
The primary goal of the project is to develop and examine methods for detecting responses to anthropogenic stresses in the Choptank River Index Site and to establish the Site as a sentinel of change for a broader domain of coastal plain ecosystems. Of particular interest are the impacts of meteorological fluctuations and nutrient management in the Choptank drainage basin on water quality and living resources in the estuary. The intent is to resolve responses caused by human activities from the variability imposed by nature, to develop key indices of ecosystem change, and to predict trends and their consequences.
The fortuitous arrival of heavy rains over the Choptank River CISNet Index Site in spring 2000, provided a substantial boost to our efforts toward the goal of developing methods for detecting responses to anthropogenic stresses. In marked contrast to the drought year of 1999, these rains and the associated runoff reduced salinity and produced intense and widespread algal blooms. The initial intent of this Index Site program was to separate responses caused by human activities from the variability imposed by nature, to develop key indices of ecosystem change, and to predict trends and their consequences. Of particular interest have been the impacts of meteorological fluctuations and nutrient management in the Choptank drainage basin on water quality and living resources in the estuary. For this 3-year program, our strategy has been to use modern, high-intensity, high-resolution sampling and analytical tools in conjunction with the historical record to achieve this separation. However, without a range of conditions within the intensive sampling interval to facilitate such an effort, success might be in doubt. Fortunately, Mother Nature cooperated. Additional fortunate occurrences of 2000 were the funding of related, cooperative programs and the publication of relevant research results from the Choptank River watershed.
Highlights of the Choptank River Index Site for 2000 included both observational and analytical efforts. Monthly axial shipboard surveys were augmented by occasional high-resolution undulating towed vehicle transits and lateral sampling. Monthly aircraft overflights coincident with shipboard surveys were successfully completed. Two autonomous sampling stations were established, and the primary monitoring buoy telemetry system was set up to report information to the Web in real time. In addition, a Choptank River Index Site Web Site was established. The full U.S. Environmental Protection Agency (EPA) historical data set was assembled and processed for analysis. Three masters theses, partially supported by EPA STAR fellowships, were completed. Finally, a steady-state transport model was completed and a manuscript prepared. This model not only showed that the relevant transport processes could be captured by relatively simple physics, especially in the upper estuary, but also indicated that a simple time-dependent model would likely be successful over the entire estuary. In October, W. Boicourt and J.C. Stevenson attended the CISNet Annual Meeting at the USEPA Narragansett Laboratory. They reported on activities and progress and conferred with colleagues from other CISNet sites.
In the next year, we intend to carry out both an intensive field effort and a program of analysis and modeling. In addition to continuing the high-resolution time series shipboard surveys as long as practical, we will conduct a 2-month intensive observational program in late spring. Although this program will address some questions not posed at the outset of the Choptank Index Site research, the primary reason for the intensity is that we intend to include special studies that were planned for 2000 but not carried out. For 2001, the field effort is designed to address transport processes and lateral property structure within the estuary, exchange of the Choptank River with the mainstem bay, and nutrient exchanges between the land, marshes, and open estuary. Although we will continue to analyze the historical record in the context of the CISNet data set, we also intend to construct a simple time-dependent transport model of the Choptank River Index Site. This model will be based on a successful advection-diffusion model previously applied to the Upper Chesapeake Bay.