Alteration of Reproductive Steroids of Male Winter Flounder (Pleuronectes americanus) Chronically Exposed to Low Levels of Crude Oil in Sediments

Abstract

When male winter flounder (Pleuronectes americanus) were held in seawater for 4 mo exposed to sand treated with five low levels of crude oil, there was a significant reduction in testosterone and 11-ketotesterone glucuronides in blood plasma. At the two higher levels of oil the concentrations of plasma glucuronides were similar but very significantly lower than in the controls or the three lower levels of oil. For both androgens the ratio of glucuronides to free steroids declined in a stepwise fashion. Free testosterone and 11-ketotestosterone plasma levels were not affected significantly by any concentration of oil in sediment. Liver weights as a percentage of body weight were significantly increased at the two highest levels of oil in the sediments, but neither body weights nor testes weights were altered by exposure to oil. It has been suggested that androgen glucuronides can function as pheromones in some fish and this is one potentially deleterious effect of exposure to oil.