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Date of Award

Spring 2023

Document Type

Masters Thesis

Department or Program Affiliation


Degree Name

Master of Science (MS)



First Advisor

Cooper, W. James, 1969-

Second Advisor

Lemkau, Karin

Third Advisor

Olson, M. Brady (Michael Brady)


Polychlorinated biphenyls (PCBs) are a group of 209 highly stable molecules that were used extensively in industry. Although their commercial use ceased in 1979, they are still present in many aquatic ecosystems due to improper disposal, oceanic currents, atmospheric deposition, and hydrophobic nature. PCBs pose a significant and ongoing threat to the development and sustainability of aquatic organisms. Our hypothesis is that PCB concentration will significantly affect development. Zebrafish (Danio rerio) were exposed to a standard PCB mixture (Aroclor 1254) for the first 5 days post fertilization, as there is a gap in knowledge during this important developmental period for fish (i.e., organization of the body). This PCB mixture was formally available commercially and has a high prevalence in PCB contaminated sites. We tested for the effects of PCB dosage on zebrafish survival, rate of metamorphosis, feeding efficiency, and growth. We found significant, dose-dependent effects of PCB exposure on mortality, feeding efficiency, and growth, but did not see a clear effect of PCBs on the rate of zebrafish metamorphosis. Most importantly, we identified a threshold PCB dosage beyond which PCB exposure had a significant impact on life-critical processes. This can further inform local management decisions in environments experiencing PCB contamination.




Polychlorinated biphenyls, Zebrafish, Development, Aquatic Management, Persistent Organic Pollutants


Western Washington University

OCLC Number


Subject – LCSH

Polychlorinated biphenyls; Zebra danio--Development; Persistent pollutants; Ecosystem management




masters theses




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