Photo-Enhanced Toxicity of Oil to Alcid Immune Function.

Oil spills are devastating to seabirds causing high levels of mortality and toxic physiological effects, especially to immune function. Sunlight exposure can further enhance the toxicity of oil to marine species by generating photodegradation products. Photo-enhanced oil toxicity to marine birds has not been studied. Therefore, the goal of this project was to investigate the toxicity and photo-enhanced toxicity of oil to lymphocyte proliferation, macrophage phagocytosis, and reactive oxygen species production in three alcid species, common murres (Uria aalge), tufted puffins (Fratercula cirrhata), and horned puffins (Fratercula corniculata). Intrinsic factors (species, age, and sex) had a more significant effect on lymphocyte proliferation than exposure to oil or photoactivated oil. Macrophage phagocytosis was significantly reduced in oil and photoactivated oil treatments, while hydrogen peroxide production was significantly increased. Interestingly, non-photoactivated oil stimulated significantly more hydrogen peroxide than photoactivated oil. The results of this project suggest that alcid immune function could be variably influenced during an oil spill depending on the species, sex, and age of the bird and the season and level of sunlight exposure.