Biology (B.S.B.)

Document Type and Release Option

Thesis (open access)

Faculty Mentor

Dr. Risa Cohen


In 2014, 4-methylcyclohexane methanol (MCHM), an industrial chemical used to wash coal, contaminated drinking water in 300,000 homes in West Virginia, USA and raised concerns about toxicity to humans and freshwater ecosystems. The Centers for Disease Control and Prevention determined that a concentration of 1 ppm was safe for human exposure. Despite the concern for human consumption, it is important to determine if MCHM has negative effects on aquatic organisms in contaminated water, particularly plankton communities that comprise the base of freshwater food webs. I exposed freshwater plankton communities in microcosms to 0, 0.5, 1 or 3 ppm MCHM under greenhouse conditions to determine whether environmentally relevant concentrations adversely affect plankton community composition and water quality. Plankton (zooplankton and phytoplankton) and water quality were sampled every 7 days for four weeks. I found that the plankton community changed following exposure to concentrations of 0.5 and 1 ppm MCHM. Although the zooplankton taxa present were the same, the proportion of copepods decreased while rotifers increased. In addition, phytoplankton (as chlorophyll a) abundance also decreased at 0.5 and 1 ppm treatment levels. Water column conductivity increased only with initial MCHM addition, and resembled the control treatment after one week. My findings suggest that MCHM contributes to loss of copepod species. Because copepods are a major food source for fish, their decline, followed by an increase in smaller-bodied rotifers, may not only reduce food availability to higher trophic levels, but also decrease species diversity.