Persistent synthetic chlorinated hydrocarbons in albatross tissue samples from Midway Atoll

Anthropogenic organic contaminants have been found in even the most remote locations. To assess the global distribution and possible effects of such contaminants, we examined the tissues of two species of albatross collected from Midway Atoll in the central North Pacific Ocean. These birds have an extensive feeding range covering much of the subtropical and northern Pacific Ocean. Anthropogenic contaminants were found at relatively great concentrations in these birds. The sum of 19 polychlorinated biphenyl (PCB) congeners ranged from 177 ng/g wet weight in eggs to 2,750 ng/g wet weight in adult fat. Total toxic equivalents (TEQs) derived from polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) ranged from 17.2 to 297 pg/g wet weight in the same tissues, while the inclusion of TEQs from PCBs increased these values to 48.4 and 769 pg/g wet weight, respectively. While contaminant concentrations varied between species and tissues, the contaminant profile was relatively uniform. The profile of contaminants detected was unusual in that much of the TEQs was contributed by two pentachlorinated congeners (2,3,4,7,8-pentachlorinated dibenzofuran and 1,2,3,7,8-pentachlorinated dibenzo-p-dioxin), and the profiles of PCB congeners did not match known sources. When compared to other studies the concentrations detected in the Midway Atoll samples were near or above the thresholds known to cause adverse effects in other fish-eating bird species.