Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental toxicants found in anthropogenic mixtures such as crude oil, air pollution, vehicle exhaust, and in some natural combustion reactions. Single PAHs such as benzo[a]pyrene (BaP) also impact fish behavior when animals are exposed in early life stages and for short periods of time. Aquatic animals such as fish may encounter BaP through road runoff and oil spills, but few studies have examined the impact of aqueous exposure on adult fish, and fewer have examined the resulting fitness-relevant behavioral consequences of BaP and PAH mixtures and their long-term persistence. This dissertation targets this gap in the literature by examining how aqueous exposure to BaP influences anxiety-like behavior, learning, and memory in adult zebrafish, and how parental exposure to the PAH mixture, crude oil, combined with hypoxia affects social and exploratory behavior in unexposed larval zebrafish. We found that learning and memory were not affected by 24 hour exposure to BaP, that anxiety-like behavior was minimally affected, and that locomotor parameters such as distance moved and times spent in darting and immobile states were significantly altered by exposure to BaP. Additionally, we found that parental exposure to crude oil and hypoxia decreased larval velocity. Additionally, we examined how crude oil, BaP, and the detergent COREXIT influence a monolayer of mouse and fish endothelial cells, as an in vitro blood-brain barrier (BBB) model. We found that exposure to BaP in particular caused significant damage to both fish and mammal in vitro BBB models, and damage to the BBB is one potential mechanism by which neural integrity and behavior may be influenced. Understanding how these toxicants influence fish brains and behavior will give insight into how fish populations explore and interact with their environment and with predators, and how these interactions persist even when toxicants are no longer present.
