Examining the impact of emerging contaminants on phytoplankton mortality, photosynthetic capacity, and community composition in South Carolina lakes

Humans rely on freshwater for vital services like drinking water, agriculture, and hygiene, yet are a top source of water quality decline. Of particular concern is the introduction of contaminants including pharmaceuticals, persistent organic pollutants, forever chemicals, and tire wear products, among others. This project aims to investigate how natural phytoplankton communities respond to exposure to four emerging contaminants: carbamazepine and diclofenac (pharmaceuticals), perfluorooctane sulfonic acid (PFOS, a persistent organic pollutant), and 6ppd-quinone (tire wear product). Each of the four contaminants has been demonstrated to cause harm to aquatic organisms across all trophic levels, but studies involving phytoplankton have focused on cultures rather than natural communities. In this study, we exposed whole water samples from Lake Murray, South Carolina to a range of environmentally relevant concentrations of each contaminant. We use High Performance Liquid Chromatography (HPLC) to determine total chlorophyll a concentration as a proxy for phytoplankton biomass and photopigment concentrations to determine group-specific responses. We also use Pulse Amplitude Modulated Fluorometry to assess photosynthetic capacity. Preliminary results suggest that at these concentrations, contaminants do not impact total biomass or photosynthetic capacity. Due to their position as the base of the aquatic food web and their role in nutrient cycling, understanding how phytoplankton respond to these ubiquitous compounds is crucial for understanding and managing ecosystem health.

Presentation Preference: Oral

Primary Presenter: Catherine Schlenker, University of South Carolina (schlenkc@email.sc.edu)

Authors:

Catherine Schlenker, University of South Carolina  (schlenkc@email.sc.edu)

James Pinckney, University of South Carolina  (pinckney@sc.edu)