Adaptation of a Population of Fundulus heteroclitus to a Creosote-Contaminated Environment: Mechanisms, Genetic Consequences and Fitness Trade-Offs

Abstract

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, The goal of this project was to elucidate the long-term multigenerational consequences for a population of fish inhabiting a polluted estuary. The project studies in detail a population of killifish (Fundulus heteroclitus) inhabiting a portion of the Elizabeth River, VA that is highly polluted with polycyclic aromatic hydrocarbons (PAHs)and related chemicals that emanated from a former wood treatment facility that used creosote. Key results included: (1) This population has adapted to this pollution. (2) However, fitness costs, such as increased sensitivity to hypoxia, were incurred. (3) These adaptations and fitness costs are in part genetically-based. (4) The molecular bases for these adaptations include alterations in the aryl hydrocarbon receptor signaling pathway and in antioxidant defense systems. (5) The dominant toxicity produced by PAH mixtures in killifish is perturbed cardiovascular development in embryos. (6) Different PAHs with different modes of action were highly synergistic in the context of developmental toxicity. This synergy has important implications for environmental assessments of PAHs. LONG-TERM GOALSThe long-term goal of this project is to understand the genetically-and physiologically-based processes by which a population of killifish (Fundulus heteroclitus) inhabiting the Elizabeth River, Virginia has adapted to its highly polluted environment, and to determine if fitness trade-offs are associated with these adaptations.