Grantee Research Project Results
2001 Progress Report: Rhode River CISNet: Estuarine Optical Properties as an Integrative Response to Natural and Anthropogenic Stressors
EPA Grant Number: R826943Title: Rhode River CISNet: Estuarine Optical Properties as an Integrative Response to Natural and Anthropogenic Stressors
Investigators: Gallegos, Charles L. , Jordan, Thomas E. , Neale, Patrick J.
Institution: Smithsonian Environmental Research Center
EPA Project Officer: Packard, Benjamin H
Project Period: October 1, 1998 through September 30, 2001
Project Period Covered by this Report: October 1, 2000 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 , Aquatic Ecosystems , Ecological Indicators/Assessment/Restoration
Objective:
The primary objective of this research project is to utilize recent 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, decadal, or longer responses to increased disturbance or to management efforts. Research to interpret continuously monitored optical properties is focused on: (1) interpretation of optical properties in terms of the concentrations of suspended particulate matter (SPM), phytoplankton chlorophyll, and colored dissolved organic matter (CDOM); (2) manipulative experiments to establish the response of in situ concentrations of chlorophyll, SPM, and CDOM, to inputs of nutrients on event to interannual time scales; and (3) process level research to examine the effects of solar UV radiation on nearshore plankton communities, as influenced by potential changes in estuarine optical properties.
Progress Summary:
Research in the first year focused on establishing a system for monitoring estuarine optical properties, installation of salinity monitors to gauge mixing and exchange in the system, and determining the response of optical properties to experimental additions of nutrients. In the second and third years, the continued collection of continuously monitored optical properties, development of data analysis procedures, and collection and Web posting of salinity data were emphasized. In the second year, measurements were extended out into Chesapeake Bay, and the system for temporal monitoring was converted into a system for spatial mapping of surface optical properties. This transformation will assist in scaling up observations made at a single location, and will be an important adjunct to remote sensing studies.
In the second and third years, we continued measuring in situ profiles of downwelling and upwelling spectral irradiance approximately weekly in the Rhode River. Water samples for determination of optical water quality parameters and inherent optical properties in the laboratory were collected along with profiles. Approximately 732 samples from the Rhode River and nearby Chesapeake Bay have now been analyzed for total, volatile, and fixed suspended solids, chlorophyll a, turbidity, absorption by CDOM, and absorption by particulate matter.
Salinity monitors to measure mixing and exchange in the Rhode River were operated at three locations in addition to the one preexisting probe. These probes have been operating since late March 1999, with interruption during periods of ice. The probes have been very reliable, experiencing few interruptions. The spring 2001 phytoplankton bloom was smaller in magnitude, but better resolved than that reported last year due to improved instrument performance.
With the optical monitoring conducted through the end of September 2001, nearly 2 full years of data were obtained. The seasonal pattern in absorption coefficient appeared remarkably similar in the 2 years. Coefficients were high in April and May, during the spring dinoflagellate blooms. The bloom in 2000 was larger than that in 2001. In each year, there was a period reduced absorption coefficient in June (about day 150), followed by a gradual increase throughout the summer and into September.
Differences between the 2 years also are apparent. The spring bloom was larger in 2000, due to a larger spring freshette from the Susquehanna River and consequently higher inputs of nitrogen that year. There was a fall bloom in each year, occurring earlier in 2000, and less apparent than in 2001. The impact of the fall bloom was made larger by the fact that it was added to a large component of detrital absorption that built up over the summer. Indeed, the highest sustained absorption coefficients were measured during that fall peak in 2001. Together, the 2 years of hourly data on inherent optical properties gives an unprecedented picture of the optical variability in a shallow coastal system.
Future Activities:
The primary activities of the remaining months of the project (as extended) will be to perform final quality control checks on the data, post all data on the Web, host/attend the final PI meeting, and prepare the final report. Major field research components of the project have been completed. One exception is that the instrumentation purchased in the final year to measure the spectral backscattering coefficients of particulate matter will continue to be used. This will allow for better prediction of the scattering-to-absorption ratio of non-algal particulate matter, and determination of its spatial variability around the upper Chesapeake Bay. Continuous monitoring of inherent optical properties continued through the end of FY 2001.
Journal Articles on this Report : 4 Displayed | Download in RIS Format
Other project views: | All 15 publications | 5 publications in selected types | All 4 journal articles |
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Type | Citation | ||
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Banaszak AT, Neale PJ. Ultraviolet radiation sensitivity of photosynthesis in phytoplankton from an estuarine environment. Limnology and Oceanography 2001;46(3):592-603. |
R826943 (2001) |
not available |
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Gallegos CL, Jordan TE. Impact of the Spring 2000 phytoplankton bloom in Chesapeake Bay on optical properties and light penetration in the Rhode River, Maryland. Estuaries 2002;25(4A):508-518. |
R826943 (2001) R826943 (Final) |
not available |
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Gallegos CL, Neale PJ. Partitioning spectral absorption in case 2 waters: discrimination of dissolved and particulate components. Applied Optics 2002;41(21):4220-4233. |
R826943 (2001) R826943 (Final) |
not available |
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Neale PJ. Modeling the effects of ultraviolet radiation on estuarine phytoplankton production: impact of variations in exposure and sensitivity to inhibition. Journal of Photochemistry and Photobiology B-Biology 2001;62(1-2):1-8. |
R826943 (2001) R826943 (Final) |
not available |
Supplemental Keywords:
ecological effects, 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 radiationProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.