Delayed effects of oil exposure on fish

Thesis (M.S.) University of Alaska Fairbanks, 2012Polycyclic aromatic hydrocarbons (PAHs) are continuously added to aqueous environments through point source and non-point source pollution and can cause deleterious effects on exposed fish populations. Historically, studies have shown that acute PAH exposure causes only short-term effects in adult fish which were resolved when the exposure ended. Chronic exposure to PAHs, however -- even at the less susceptible juvenile and adult stages -- can cause a host of effects including lesions, lower body length and weight, and reduced swimming ability. More recently studies of embryonic fish have demonstrated that much lower PAH concentrations can cause lethal and sub-lethal effects on those embryos and can cause delayed effects on the fish that are not seen until adulthood. This study used zebrafish (Danio rerio) to examine the effects of 48-hour weathered crude oil exposure on both the embryonic fish exposed and the adult fish exposed as embryos but raised in clean water. Oil exposed embryos had increased mortality, pericardial edema, intracranial hemorrhage, and higher cytochrome P4501A (CYP1A) activity. Adult fish exposed as embryos had decreased critical swim speed and rounder hearts than the control fish. These effects may culminate in decreased fitness of the exposed fish population