NEGATIVE IMPACTS OF OIL AND GAS PRODUCED WATER DISPOSAL ON SURFACE WATER ECOLOGY: FRESHWATER MUSSEL BIOMONITORING CAPABILITIES AND RADIUM BIOACCUMULATION

Due to their sessile and filter-feeding nature, freshwater mussels are highly vulnerable to oil and gas produced water (OGPW) disposals and accompanying impaired water quality containing elevated total dissolved solids and naturally occurring radioactive materials. Pollution exposures and habitat modifications have compromised mussel abundance and spatial distribution, leading to increased stress and mortality. This research aims to quantify the ecological impact of OGPW disposal by investigating bioaccumulation of harmful contaminants and utilizing unique chemical signatures such as ²²⁸Ra/²²⁶Ra and ⁸⁷Sr/⁸⁶Sr isotopic ratios seldom explored in filter feeding organisms. We find that watersheds impacted by oil and gas activities have demonstrated decreased juvenile mussel growth and increased mortality downstream of direct exposures. Furthermore, field research in areas impacted by disposals demonstrated significant radium-226 and radum-228 bioaccumulation up to 5 km downstream of the outfall location in both hard shell and soft tissue of sampled adult freshwater mussels. Combined evidence from conducted laboratory and field studies supports the use of ²²⁸Ra/²²⁶Ra and ⁸⁷Sr/⁸⁶Sr isotopic ratios, as well as metal/Ca ratios in exposed freshwater mussels to fingerprint OGPW disposals in the Appalachian region broadening previous biomonitoring capabilities and informing aquatic health risks associated with OGPW exposures to freshwater biota.