Rhode River CISNet: Estuarine Optical Properties as an Integrative Response to Natural and Anthropogenic Stressors

EPA Grant Number: R826943
Title: Rhode River CISNet: Estuarine Optical Properties as an Integrative Response to Natural and Anthropogenic Stressors
Investigators: Gallegos, Charles L. , Correll, David L. , Jordan, Thomas E. , Neale, Patrick J.
Current Investigators: Gallegos, Charles L. , Jordan, Thomas E. , Neale, Patrick J.
Institution: Smithsonian Environmental Research Center
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1998 through September 30, 2001
Project Amount: $510,181
RFA: Ecological Effects of Environmental Stressors Using Coastal Intensive Sites (1998) RFA Text |  Recipients Lists
Research Category: Environmental Statistics , Ecosystems , Ecological Indicators/Assessment/Restoration


Objectives/Hypotheses: Coastal ecosystems are impacted by a wide range of anthropogenic and natural stressors that vary tremendously from site-to-site. Natural variability in ecological characteristics of widely distributed coastal ecosystems translates directly to similar variability in response to stresses. In spite of such geographic variability, many of the stresses that are common to all regions result in characteristic changes in the spectral attenuation of light underwater. The penetration of light underwater and its spectrum are determined by the concentrations of suspended particulate matter (SPM), phytoplankton chlorophyll (Chl), and colored dissolved organic matter (CDOM). These three parameters integrate a system's response to a wide range of stressors, both natural and anthropogenic. We propose to utilize advances in monitoring of estuarine spectral optical properties to develop the capability to continuously monitor concentrations of optically active parameters as an integrated measure of estuarine response to perturbations on time scales ranging from individual storms or phytoplankton blooms, to seasonal, to decadal or longer responses to increased disturbance or to management efforts.


Our approach is to supplement ongoing measurements of nutrient fluxes from the watershed with automated instruments to measure water exchanges throughout the Rhode River subestuary, and to monitor spectral absorption and scattering coefficients at a centrally located site. Research to interpret the monitored data and to utilize it to improve the environmental decision-making process will be focused in the following 3 areas: (1) research to interpret light spectra in terms of the concentrations of SPM, Chl, and CDOM; (2) manipulative experiments to establish the response of in situ concentrations of chlorophyll, DOC, and SPM to inputs of nutrients (both watershed discharge and atmospheric deposition) and particulate matter on event to interannual time-scales; (3) process level research to examine the effects of solar UV (and especially UV-B) radiation on nearshore plankton communities, as influenced by estuarine optical properties.

The research will be conducted at the Rhode River, Maryland, a tributary embayment on the western shore of Chesapeake Bay. The site includes an array of ecosystems comprising a landscape of coastal plain forests in varying successional stages, agricultural fields, fresh and brackish water wetlands and marshes, and open estuarine waters. Basic physical and chemical parameters and selected populations have been monitored at the site since the early 1970's.

Expected Results:

Products of the research will include a monitoring system and interpretive algorithms for documenting event-scale, seasonal, and long-term changes in SPM, Chl, and CDOM, three parameters that gauge many facets of the health of estuaries everywhere. This transportable capability to measure and interpret water column optical properties will provide valuable sea-truth data for remote sensing programs wherever implemented. Process-level research will improve the environmental decision-making process, by establishing comparative mechanisms by which nutrient inputs by watershed discharge and precipitation affect trophic structure of an estuary, resulting in measurable and interpretable variations in estuarine optical properties on multiple time scales. Additional process-level research will provide predictive capability for evaluating the impact of UV-B irradiance, as any such influence in coastal and estuarine systems will be modulated by interaction with water column optical properties.

Publications and Presentations:

Publications have been submitted on this project: View all 15 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 4 journal articles for this project

Supplemental Keywords:

ecological effects; precipitation; nutrients; indicators; environmental chemistry; marine science; modeling; monitoring; Chesapeake Bay., RFA, Scientific Discipline, Water, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Water & Watershed, Nutrients, Ecology, estuarine research, Environmental Chemistry, Ecosystem/Assessment/Indicators, Ecosystem Protection, State, Chemistry, Ecological Effects - Environmental Exposure & Risk, Air Deposition, Environmental Monitoring, Ecology and Ecosystems, Ecological Risk Assessment, Watersheds, Ecological Indicators, Chesapeake Bay, anthropogenic stress, aquatic ecosystem, coastal ecosystem, dissolved organic matter, nutrient supply, ecological exposure, anthropogenic stresses, monitoring, CISNet, estuaries, UV effects, bioavailability, natural stressors, esturarine eutrophication, Rhode River, phytoplankton dynamics, UV radiation, environmental decision-making, aquatic ecosystems, nutrient cycling, water quality, plankton, stress responses, UV-B, atmospheric deposition, Maryland, UV-B radiation

Progress and Final Reports:

  • 1999 Progress Report
  • 2000 Progress Report
  • Final Report