PERSISTENT SYNTHETIC CHLORINATED HYDROCARBONS IN ALBATROSS TISSUE SAMPLES FROM MIDWAY ATOLL

Anthropogenic organic contaminants have been found in even the most re mote locations. To assess the global distribution and possible effects of such contaminants, we examined the tissues of two species of albat ross collected from Midway Atoll in the central North Pacific Ocean. T hese birds have an extensive feeding range covering much of the subtro pical and northern Pacific Ocean. Anthropogenic contaminants were foun d at relatively great concentrations in these birds. The sum of 19 pol ychlorinated 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 dib enzofurans (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 conc entrations varied between species and tissues, the contaminant profile was relatively uniform. The profile of contaminants detected was unus ual in that much of the TEQs was contributed by two pentachlorinated c ongeners (2,3,4,7,8-pentachlorinated dibenzofuran and 1,2,3,7,8-pentac hlorinated dibenzo-p-dioxin), and the profiles of PCB congeners did no t match known sources. When compared to other studies the concentratio ns detected in the Midway Atoll samples were near or above the thresho lds known to cause adverse effects in other fish-eating bird species.