Physical Sciences and Mathematics Commons^™

2019 Chesapeake Bay Dead Zone Report, Virginia Institute Of Marine Science, Anchor Qea

Reports

The “Dead Zone” of the Chesapeake Bay refers to a volume of bottom water that is characterized by dissolved oxygen concentrations less than 2 mg/L, which is too low for aquatic organisms such as fish and blue crabs to thrive. The Chesapeake Bay experiences such “hypoxic”conditions every year, with the severity varying from year to year, depending on nutrient and freshwater inputs, wind, and temperature. Multiple metrics are used to relate the severity of hypoxia between different years:

• Maximum Daily Hypoxic Volume (km3): The maximum volume of Chesapeake Bay water experiencing hypoxic conditions on any given day

• Average Summer Hypoxic …

The Presence Of Above Standard Levels Of Commonly Tested Contaminants In Communiites On Long Island, New York: The Impact Of Income On Untreated Water Quality, Amy Catalano, Michael A. Marino Ed.D.

Faculty Works: Biology, Chemistry, and Environmental Studies

Water quality is a pressing issue in many communities. Long Island (LI), New York, rests on a system of aquifers created by prehistoric glacial activity. These aquifer systems are the only source of drinking water for LI. Water quality issues are pervasive in the region due to nitrate pollution, caused by antiquated septic systems in much of the Island, as well as the prevalence of environmental clean-up sites. Using the Watertraq database, we searched for levels of select compounds that were present in wells above acceptable levels on LI. We then collected demographic data from the U.S. Census, including income, …

Water Quality In An Unnamed Branch Of Pungoteague Creek, Bobtown Road And Hollies Church Road, Va., Richard A. Snyder, Paige G. Ross

Reports

Previous sampling of the stream crossing Bobtown Road (Rt 178) near the intersection of Hollies Church Road (Rt. 620), had indicated high levels of nitrogen in the stream flow (Snyder and Ross, 2019). During a dry period, total nitrogen was determined as 21.932 mg/L, at the end of a rain event 9.56 mg/L was recovered, and during an extended wet period without major rainfall, a value of 18.26 mg/L was found. The lower value associated with the rain event suggested dilution of a ground water source. The proximity of the retired Accomack County Landfill upstream of the site triggered a …

Water Quality In Southern Accomack County Watersheds, Richard A. Snyder, Paige G. Ross

Reports

Expansion of poultry grow out houses in Accomack County, VA has raised concerns for water quality impacts both seaside and bayside where harvesting marine resources and aquaculture operations may be affected. The dust and litter from the poultry houses are potential sources of nitrogen, phosphorous, and fecal contamination to watersheds and receiving waters. Siting regulations, storm water controls, and management of litter storage and handling are designed to limit these impacts, yet no analysis has been implemented to verify the efficacy of these protective measures. This investigation sampled watersheds after a 2 week dry period prior to a storm event …

Using Bayesian Networks To Predict Risk To Estuary Water Quality And Patterns Of Benthic Environmental Dna In Queensland, Scarlett E. Graham, Anthony A. Chariton, Wayne G. Landis

Institute of Environmental Toxicology & Chemistry Publications

Predictive modeling can inform natural resource management by representing stressor-response pathways in a logical way and quantifying the effects on selected endpoints. This study demonstrates a risk assessment model using the Bayesian network-relative risk model (BNRRM) approach to predict water quality and; for the first time, eukaryote environmental DNA (eDNA) data as a measure of benthic community structure. Environmental DNA sampling is a technique for biodiversity measurements that involves extracting DNA from environmental samples, amplicon sequencing a targeted gene, in this case the 18s rDNA gene which targets eukaryotes, and matching the sequences to organisms. Using a network of probability …