Effects of oilfield brinewater discharges on Western sandpipers (Calidris mauri) in Nueces Bay, Texas

Western sandpipers (Calidris mauri) were studied at an oilfield brinewater discharge site near Corpus Christi, Texas, and at a reference site near Galveston, Texas. Morphological indices, hepatic monooxygenase activities, and contaminant burdens were quantified to evaluate exposure and effects. Pooled stomach contents of birds collected at the discharge site contained higher concentrations of petroleum hydrocarbons than the reference site. Total pristane concentration, and the ratio of pristane:n-heptadecane in sandpiper carcasses were significantly greater at the oil discharge site, indicative of chronic exposure. Concentrations of other organic contaminants (petroleum aromatic hydrocarbons, polychlorinated biphenyls and organochlorine pesticides and metabolites) in carcasses at both study sites were relatively low. Neither body weight, bill length or hepatic monooxygenase activities differed between sites, although liver weight and liver weight:body weight ratio were significantly lower at the discharge site. These data suggest that oilfield brinewater discharges have only limited toxicity to sandpipers wintering near the site.