Analyses of Kings Creek Water and Watershed Runoff Samples for Bacteroidales using qPCR to Detect Human Fecal Contamination

The purpose of this work was to evaluate and analyze water samples collected from the Kings Creek watershed using a qPCR-based method to detect both total Bacteroidales and Bacteroidales reported to be associated with human fecal contamination. Quantitative real-time PCR assays were used to significantly reduce processing times and at the same time yield estimates of target concentrations. Initial efforts focused on evaluation of various Bacteroidales primer sets reported in the literature tested against human and animal fecal samples collected from the Kings Creek watershed. Most samples, both animal and human, were positive with the universal (i.e. general or total) Bacteroidales assay. Strong positive signals were found with human sewage using the humanspecific assay that was chosen for this study. Most animal scat samples were negative with respect to the human-specific Bacteroidales indicator. The few animal samples that were positive with the human-specific assay had very low signal intensity. Despite the generally pervasive drought conditions during this study, evidence of human contamination was detected at certain feeder stream locations, and was widespread after a significant rain event that occurred in late fall. Use of the human-specific Bacteroidales indicator holds promise as a tool to identify potential human, as opposed to animal, sources of contamination but will require a more comprehensive field monitoring and sample collection effort than could be managed in this preliminary study

Categorization of shellfish TMDL sites Final Report

There were two important goals for this project, including the assembly and compilation of digital data for the Coastal Plain and tidal waters of Virginia, and the categorization of the Division of Shellfish Sanitation (DSS) shellfish growing areas to determine if some are similar enough for water quality models to be effectively transferred from the modeled growing areas to other areas. This report summarizes the data and statistical analyses and discusses the results. Note: The digital data has a very fine resolution. The maps displayed in this report cannot convey this information on 8.5x11 paper. All digital data layers (shape files and grids), digital maps (jpgs), data files (excel files) and a digital copy of this report (pdf format) are included on 3 cdroms that accompany this report. The cdroms include a text file (called Readme.txt) that provides an explanation of each of the data layers and pertinent information in the tables contained in the data layers

The effect of the Chesapeake Corporation on the water quality of the upper York River with respect to total and fecal coliforms and fecal streptococci

Levels of total and fecal coliforms and fecal streptococci in the Mattaponi, Pamunkey and York Rivers were monitored for one year in the vicinity of the town of West Point, Virginia. These parameters were also determined for selected process waste waters and effluents from the Chesapeake Corporation, West Point, Virginia

Evaluation of salinity and temperature as stress factors affecting the enumeration of fecal coliforms by the electrochemical detection method

The ability of an electrochemical detection method to predict viable numbers of fecal coliforms was evaluated under laboratory conditions with respect to seawater adjusted to various salinities and temperatures. The viability of an Escherchia coli isolat~ as measured by the spread plate technique utilizing non-selective media was unaffected after 12 wk exposure at 2°C and 25 °100 salinity. At higher temperatures (15-30°C) both the total decrease in cell numbers as well as the rates of die-off were greater than at 2°C. There was little apparent difference in viability across the temperature range 15-30°C. Viability was observed to be inversely related to salinity over the range 10-30 °100. Stress was measured using the electrochemical detection method (ECDM) and defined as the difference between the predicted endpoint response time (ER) calculated from a standard curve and the observed ER time. Seawater of higher salinities generally produced greater stress. (...

Bacterial Biomass And Heterotrophic Potential in the Waters of the Chesapeake Bay Plume and Contiguous Continental Shelf

Bacterial populations in Chesapeake Bay and contiguous shelf waters are significant to such essential processes as mineralization, nutrient recycling, degradation of pollutants and biomass production. However, our understanding of such dynamic relationships of physical and chemical factors to bacterial biomass and activities in Chesapeake Bay plume waters is limited. The availability of synoptic hydrographic (and remotely sensed physical-chemical) data obtained simultaneously with measurement of of microbial biomass and activity presented an opportunity to examine such relationships.https://scholarworks.wm.edu/vimsbooks/1130/thumbnail.jp