By Katie Burbridge

Faculty Mentor: Dr. Ben Kisila

Abstract

Aquatic environments endure continual threat by anthropogenic influence as global population and development increases. Industrial activities, agricultural expansion and urbanization exacerbates the transfer of sediments and associated contaminants, including trace metals, to aquatic ecosystems leading to potential bioaccumulation of toxic elements in both wildlife and human populations. This study evaluates trace metals loading in the sediments of Chincoteague Bay, a 72.4 square mile lagoon of the coastline of Virginia and Maryland. Thirty (30) surface sediment grab samples, seven (7) sediment cores and dagger blade grass shrimp (Palaemon pugio) were used to analyze the spatio-temporal variability in the sediments and bioaccumulation. All samples were analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP) for elemental concentrations of Al, As, B, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Pb, Se, Zn, Li, and Ni. Geo Accumulation index (Igeo), enrichment factors (EF), Pollution load index (PLI), Geographic Information System (GIS) based Hot Spot Analysis, and Pearson Correlations (PC) statistical analysis were used to identify potential sources.
Preliminary results indicate varying PLI ranges, the highest contamination values being spatially adjacent to inland agricultural areas and proximity to major roads in Chincoteague urban center. Majority of EFs were classified as significant enrichment (5 < 20) but varied spatially with limited correlation, suggesting multiple trace metal sources. Igeo values ranged from uncontaminated (≤ 0) to moderate to heavy contamination (2-3), collectively decreasing alongside the Town of Chincoteague and increasing near Chincoteague Road and Virginia’s mainland. GIS based Hot Spot Analysis suggests trace metal concentrations increase alongside Virginia’s mainland including near Wallop flight facility, with exception of arsenic (As) that is relatively higher near Chincoteague urban center. The present results shows agriculture, nearby Wallops facility and urbanization as plausible sources of the contaminants. The dagger blade shrimp (Palaemon pugio) samples and dated core samples will provide additional potential bioaccumulation and temporal variability of trace metals in Chincoteague Bay.