WATER RESOURCES RESEARCH GRANT PROPOSAL
Project ID: 2006DC77B
Title: Nutrient flow and biological dynamics in the Anacostia River
Project Type: Research
Start Date: 03/01/2006
End Date: 02/28/2007
Congressional District: District of Columbia
Focus Categories: Nutrients, Solute Transport, Water Quality
Keywords: microbial community structure, carbon and nutient sources, effects of nutrient loading
Principal Investigators: MacAvoy, Stephen E.; Bushaw-Newton, Karen L.
Federal Funds: $15,000
Non-Federal Matching Funds: $5,850
Abstract: Rivers are longitudinally linked systems with processes occurring in the upper reaches impacting downstream reaches and processes occurring in downstream reaches impacting upstream reaches through biological migration. The Anacostia River is an important link between the terrestrial and aquatic regions of the Potomac watershed and the larger Chesapeake Bay system. Although the health of the Potomac Estuary has been improving in recent years (Walker et al. 2004; Carter and Rybioki 1986), the Anacostia River, which runs into the estuary, remains a seriously stressed system with high levels of PAHs, PCBs, pesticides, and heavy metals (Phelps 2004). Researchers have also observed elevated concentrations of Aeromonas spp. during the summer months in Anacostia waters relative to concentrations observed in most natural waters (Cavari 1981). The effects of the degraded condition have been far reaching on the biological communities with high mortality rates of filter feeding bivalves (Phelps 1993, 2004); high tumor incidence among resident bullhead catfish (Sakaris et al. 2005, Pinkney et al. 2004), and adverse impacts on the populations of invertebrate macrofauna (Phelps 1985). These effects may impact the microbial community as well. Microbial DNA isolated from sediment from several locations on the Anacostia River reflecting a pollution gradient of heavy metals and organics (see Velinsky et al. 1994 and Wade et al. 1994 for sites), was found to have unique signatures in different regions of the river (Bushaw-Newton, Adams, and Velinsky, unpublished data). Despite increased attention on the Anacostia's environmental degradation, improvements have been marginal (Hall et al. 2002). Benthic organisms remain rare; Asiatic clams experience extremely low survival and have not established resident populations; fish remain unsafe to eat; and over 100 million gallons of raw waste entered the river in the past two years (Washington Post 2005). While studies have concentrated on the larger, macrofauna, little attention has been paid to the microbial and the macroinvertebrate communities. Yet, the structure and function of these two communities often plays a key role in dictating the structure and function of the larger biological community as well as the chemical components of the system. Therefore in order to best improve and protect the ecological function of the rivers, it is imperative to understand the role of the microbial community within that system. Our objectives are to evaluate the 2 microbial and macroinvertebrate communities of several sites within the upper reaches of the Anacostia River, upstream and downstream of the combined sewage outflow are in Bladensburg Maryland. We will 1) establish seasonal changes in biological oxygen demand, developing profiles of demand versus depth, 2) evaluate nutrient sources to bacteria, algae, invertebrates and characterize the origins of particulate organic matter through the use of the stable isotopes of sulfur, carbon and nitrogen, 3) characterize the composition of microbial communities at the different sites by DNA analysis, fatty acid profile and standard microbiological techniques.
Progress/Completion Report, PDF