Tracking Toxins: Investigating Organic Contaminants Produced by Harmful Algal Blooms in New Jersey Waters​ ​

Elizabeth Macchioni

Co-Presenters: Individual Presentation

College: Hennings College of Science Mathematics and Technology

Major: BS.ENVIRSCI

Faculty Research Mentor: Liu, Shuting  

Abstract:

Harmful algal blooms (HABs) are an increasing concern for New Jersey's freshwater environments, where nutrient enrichment and climate-driven global warming promote toxin-producing phytoplankton. This study evaluates temporal patterns of multiple HAB-associated organic toxins, such as microcystins (MC-LR, MC-RR, MC-YR), dinophysistoxin (DTX1, DTX2), pectenotoxin-2 (PTX2), brevetoxin-2 (PbTx2), domoic acid (DA), and azaspiracids (AZA1, AZA2) along with water quality parameters (temperature, dissolved oxygen (DO), pH, salinity, chlorophyll, and specific conductivity) measured with a YSI sonde at two New Jersey lakes (Lake Hopatcong and Weequahic Lake) over three months in the summer of 2025). DTX1 concentration increased from June to August in Lake Hopatcong. Microcystin concentrations in the Weequahic Lake were over one order of magnitude higher than those in Lake JHopatcong and reached their highest values in July, corresponding to microcystis blooms. Correlation analysis revealed a positive correlation (r≈0.7) between DO and microcystins, and a negative correlation between DTX1 and pH (r≈ -0.77), suggesting that conditions favored by algal blooms promote toxin production. HABs are often treated by algicide addition. We will also evaluate the effect of algicide on toxin release from cell lysis. Overall, these findings offer insight for local water resource managers and contribute to ongoing statewide efforts to mitigate risks to public health, aquatic ecosystems, and coastal economies.