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Congratulations to Daniel Brown, an ITEHP graduate student in Richard Di Giulio’s laboratory, who recently received the 2014 Pat McClellan-Green student travel award!
Dan will be using the grant to attend the 2014 SETAC (Society of Environmental Toxicology and Chemistry) Meeting in Vancouver. The title of his oral presentation is “Sublethal Embryonic Exposure to Complex PAH Mixtures Alters Later Life Behavior and Swimming Performance in Fundulus heteroclitus.”
Polycyclic aromatic hydrocarbons (PAHs) are important environmental contaminants in many aquatic systems. Acute embryonic exposure to PAHs is known to cause cardiac teratogenesis in fish, and research has shown that early life exposure to some types of hydrocarbons causes heart alterations and decreased swimming capacity in fish. A population of Atlantic killifish inhabits a Superfund site (Atlantic Wood Industries, Norfolk, VA—AW) that is heavily contaminated with a mixture of PAHs from former creosote operations. This population has developed resistance to the acute toxicity and teratogenic effects caused by the chemical mixture in sediment from the site. Little is known about the impacts of more subtle, early life exposures, which are arguably broadly applicable to environmental contamination scenarios. This study examined the later life behavioral and performance consequences of early life exposure to low dose concentrations of PAH mixtures in both the adapted and unadapted Atlantic killifish. Atlantic killifish from King’s Creek (KC—non-polluted reference site) and the AW site were manually spawned and F1 embryos were collected and screened for normal development at 24 hours post fertilization (hpf). Embryos from both populations were then exposed to non- teratogenic dilutions (0.1% and 1.0%) of Elizabeth River sediment extract (ERSE), from the AW site, for 144 hpf. Forty embryos per treatment from both fish populations that did not display cardiac abnormalities were split into groups of 20 treated killifish for behavioral assays and 20 treated for performance testing. Killifish used for behavioral screens and swimming performance were reared in flow-through systems for 3 months and 5 months respectively. Larval killifish were evaluated for light/dark swimming activity at 4 and 8 days post hatch (ph) as well as startle habituation, and diving/exploring behavior at 3 months ph. Larval KC killifish showed decreased swimming activity as ERSE exposure concentration increased whereas, AW killifish showed increasing swimming activity with increasing embryonic exposure. Juvenile KC killifish exposed to 1.0% ERSE were hyperactive in startle response testing relative to control killifish and demonstrated reduced exploring behavior in the dive test. KC killifish raised to 5 months ph had decreasing maximum velocity at failure and reduced critical swimming capacity (Ucrit) following embryonic exposure to ERSE. Conversely, AW killifish improved as embryonic ERSE exposure increased. AW killifish consumed less oxygen at rest than KC killifish. Supported by NIEHS Superfund Program, P42-ES10356.