2001 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: Hahn, Intaek
Project Period: September 15, 1998 through September 14, 2001 (Extended to September 14, 2002)
Project Period Covered by this Report: September 15, 2000 through September 14, 2001
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 overall objective of this research 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 specific objectives of the research project are to: (1) resolve responses caused by human activities from the variability imposed by nature; (2) develop key indices of ecosystem change; and (3) predict trends and their consequences.
Chief highlights from within the Choptank Coastal Intensive Site Network (CISNet) program in 2001 involved the construction of nutrient burial estimates from core analysis, expansion of the high-resolution time-series observations, and production of an interactive geographic information system (GIS)-based data structure for delivery to a wide variety of users. The expansion of the time-series observations occurred through internal CISNet efforts, and through linking and collaborating with related programs. The award of the Science to Achieve Results (STAR) grant to the Atlantic Coast Environmental Indicators Consortium (ACE-INC) Estuaries and Great Lakes (EaGLes) program is especially gratifying because it provides a mechanism to continue a portion of the CISNet program, and thereby allows a long-term assessment of the effects of land use on ecosystem health. Core analysis from the Choptank River CISNet site indicated that sedimentation rates varied from < 1 kg m-2 y-1 to > 5 kg m-2 y-1. In our cores, organic carbon ranged from 7-39 percent C, total nitrogen ranged from 0.5-1.6 percent N, and total P ranged from 0.06-0.2 percent P. Using deep values of N and P concentrations, estimates of N and P burial were 8-43 g m-2 y-1 and 0.5-3.7 g m-2 y-1 (n=23), respectively. These relatively high rates clearly indicate these tidal marsh sediments as important sinks for N and P in this system. Trends in water column N and P over the 3-year CISNet program were dishearteningly upward throughout the upper Choptank River.
In 2002, we will be working toward completing the analysis and reporting of the Choptank Index Site program, and transitioning field activities from CISNet to the ACE-INC EaGLes program at the end of the spring bloom, 2002. We will be coordinating spring-bloom CISNet sampling with the Chesapeake Bay ECOHAB instrument array in the Choptank River. We also will renew efforts to recover the Castle Haven CISNet Acoustic Doppler Current Profiler (ADCP). We are intending to extrapolate the core analysis to the entire ecosystem. This will be a challenging endeavor. We expect to meet these challenges by exploiting patterns of nutrient burial relative to the distance from the river bank to make our best estimates. We will work with Dr. Tom Fisher?s GIS group to better effect this extrapolation. Our preliminary analysis suggests that, like in the Patuxent River, a high proportion of N and P input to the upper Choptank River is ultimately buried in marsh sediments.