Assessing the presence, concentration, and impacts of trace element contamination in a Chesapeake Bay tributary adjacent to a coal ash landfill (Possum Point, VA).

Coal ash (CA) is an industrial waste product that has been shown to contain several neurotoxic constituents such as cadmium, selenium, mercury, lead, and arsenic. Contaminant-laced leachates enter the environment via seepage, runoff, permitted discharge, or accidental spills from CA storage ponds or landfills which may pose a risk to wildlife residing in receiving waterways. In this study, we assessed 1) the presence and concentration of thirteen trace elements (Al, Ca, Mg, Cr, Cd, As, Se, Pb, Cu, Zn, Mn, Fe, B) in surface water and sediment grab samples using ICP-OES, 2) the temporal variability of trace elements using Pb-210 dated sediment core samples, 3) differences in species diversity using environmental DNA (eDNA) analyses, and 4) the presence and concentration of trace metals in banded killifish (Fundulus diaphanus) epaxial muscle tissue collected from waterways surrounding the Possum Point Power Station (Stafford, VA). Results showed the highest concentrations of As, Cd, Cr, Cu, Fe, Mg, Se, Zn, and B in Quantico Creek (QC) adjacent to the coal ash ponds and elevated average cadmium and zinc concentrations compared to both upstream and downstream locations along the Potomac River. Sediment core profiles and Pb-210 analyses showed historical enrichment of several trace elements in QC beginning after the commissioning of the power plant in 1948. When compared to upstream and downstream sites, species diversity was drastically reduced in Quantico Creek based on eDNA identification. Muscle tissues of banded killifish collected in Quantico Creek displayed increased Al, Cd, and Zn concentrations compared to upstream and downstream sites. Collectively, our results demonstrate the potential impacts of coal ash landfills on aquatic ecosystems and suggest that further research is needed to fully inform risk assessment and remediation efforts.

Investigating the potential impacts of coal ash runoff on the freshwater Seminole ramshorn snail (Planorbella duryi) under laboratory conditions.

Coal fly ash is an industrial waste product generated by coal fired powerplants which has been shown to contain elevated concentrations of several toxic trace metals. When stored in landfills or other repositories, these trace metals can enter nearby surface waters via a number of routes including leaching or runoff. Our study examined 1) the presence and concentration of eleven trace elements in a range of lab-created coal ash leachate solutions at neutral pH using ICP-OES, 2) the physiological effects of these leachate solutions on a freshwater gastropod (Planorbella duryi), and 3) the ability of these trace metals to bioaccumulate in the tissues of exposed individuals. As, Cd, Cu, Mg, Mn, and Pb were detected in solutions at increasing concentrations concurrent with ash concentration. Exposure to leachates caused significant delays in embryonic development, reduced juvenile shell growth, decreases in egg and clutch production, and the display of avoidance behaviors. Tissues of exposed snails contained elevated concentrations of As, Cd, Cu, and Cr, with bioconcentration factors 177,550 times higher in cadmium and 85,468 times higher in arsenic in the highest treatment compared to control organisms. Our results highlight the potential harmful effects of coal ash leachates on a novel freshwater invertebrate species using several unique methodologies, providing key information regarding their potential impacts on surrounding aquatic ecosystems.

The effect of freezing rate on the quality of striped bass sperm.

Several studies have been conducted in an attempt to determine the optimal freezing rate for cryopreservation of striped bass (Morone saxatilis) sperm. In this study, the effects of freezing rate (-10 °C, -15 °C, -20 °C, and -40 °C/min) on gamete quality was examined, using Sybr-14 and propidium iodide to determine viability (sperm cell membrane integrity), ATP concentration using a luciferin-luciferase bioluminescence assay, and a CEROS computer-assisted sperm analysis system to characterize striped bass sperm motion. Adult male striped bass (N = 12) were sampled once a week for 5 weeks. Collected samples were extended, cryoprotected using a 7.5% (vol/vol) dimethyl sulfoxide final concentration solution, and frozen using a Planer Kryosave controlled-rate freezer. Samples were stored in liquid nitrogen for 49 days, and sperm quality was re-evaluated after thaw (same methods). Sperm cryopreserved at -40 °C/min resulted in means for total motility (10.06%), progressive motility (7.14%), ATP concentration (0.86 pmol/10(6) cells), and sperm viability (56.5%) that were greater (P < 0.05) than those for slower cooling rates. Therefore, -40 °C/min was the optimal freezing rate (among those tested) for cryopreservation of striped bass sperm.