Effects of Pharmaceutical Pollution on Cognitive Functioning and Anxiety-like Behaviors in Crayfish

Saron Ghebrezadik, Ximena Guillen, Faith Lockhart, and Indira Nathoo

Agnes Scott College, Department of Biology, Class of 2022, ‘23, ‘24 

Over the years, aquatic species have been exposed to pollution attributed to the pharmaceutical industry. The disposal of these pharmaceutical products has damaged different levels of ecosystems to the point that the animals inhabiting these areas have shifted in behavior. Crayfish are an essential part of stream ecosystems because they eat invertebrates, decompose leaf litter, and cycle nutrients. They can become abundant in urban rivers because they are stress-tolerant. Still, they are sensitive to pH levels in the water, which can fluctuate greatly depending on their exposure to wastewater pollution. In response, significant mortality rates can affect stream ecosystem processes such as algae growth, oxygen levels, and nutrient cycling. For this research project, we will study how crayfish behavior is affected by constant exposure to a pharmaceutically polluted environment. Specifically, we plan to investigate the association between acetaminophen, the main ingredient of many over-the-counter medications, and its effects on anxiety-like behavior and learning and memory in crayfish. It is hypothesized that chronic exposure to acetaminophen will increase anxiety-like behaviors in crayfish and impair spatial learning. This is important because crayfish, in this instance, often act as keystone species and serve as bioindicators whose performance and prosperity reflect the environmental status of their particular habitat and can help scientists to make inferences of water quality and animal efficiency and mortality in response to pollution levels.