The fecal porphyrin profile in river otters as a biomarker of the effects of oil exposure

Abstract

The use of profiles of fecal porphyrins in river otters as a biomarker of the effects of oil exposure was investigated. A high-performance liquid chromatography method was developed to quantify porphyrins and compared to a spectrofluorometric method. Profiles of porphyrins were characterized in fecal samples collected at oiled and nonoiled areas in Prince William Sound following the Exxon Valdez oil spill. Levels of porphyrins in fecal samples indicated a temporal pattern of physiological stress and recovery similar to that described by other biomarker studies. Profiles of porphyrins were also characterized in fecal samples from southeast Alaska and contributed to the establishment of a baseline for fecal porphyrin excretion in coastal river otters. No significant difference in porphyrin excretion occurred between treatment groups of river otters experimentally dosed with oil. The experimental results suggest that heme metabolism in river otters may be effected by captive conditions.