Date of Award

5-2024

Document Type

Thesis

Degree Name

Master of Science (MS)

College/School

College of Science and Mathematics

Department/Program

Biology

Thesis Sponsor/Dissertation Chair/Project Chair

Matthew Schuler

Committee Member

John A Smallwood

Committee Member

Lisa Hazard

Abstract

Salt pollution caused by excessive deicer application on impervious surfaces is polluting freshwater ecosystems and negatively affecting freshwater organisms in temperate regions. Freshwater environments near oceans experience natural salt intrusion due to tidal cycles and storm events. Therefore, populations of freshwater organisms near marine environments might have evolved a tolerance to increasing salinities over millennia. This contrasts with freshwater organisms far from coasts that have experienced high baseline salt concentrations for the last few decades. The evolutionary effects of increasing salinities on freshwater organisms near and far from marine environments are not fully understood. Understanding differences in evolutionary responses to salt pollution in zooplankton is crucial for maintaining the diversity of freshwater ecosystems. To investigate this, I studied the abiotic and biotic responses of four ponds with different baseline salinities and sources of increasing salinity to understand the resilience of zooplankton populations to survive excessive exposure to salt pollution. The results indicate that total chlorophyll, phycocyanin, dissolved oxygen, total abundance, species richness, and species diversity were all negatively affected by increasing salt pollution. The results also suggest that the response of zooplankton depends on previous exposure, where zooplankton populations residing in environments near marine systems demonstrated a positive response to higher salt concentrations, as opposed to populations situated farther away from marine habitats, which showed a negative response to increasing salt concentrations. These results highlight the importance of considering historical salinities when determining the ecological consequences of human-induced pollution, such as freshwater salinization.

File Format

PDF

Download

Share

COinS