Persistent Synthetic Chlorinated Hydrocarbons in Albatross Tissue Samples From Midway Atoll

Abstract

Abstract-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.

Albatross Species Demonstrate Regional Differences In North Pacific Marine Contamination

“…The extreme differences observed between Black-footed and Laysan Albatross contaminant concentrations is not likely due to differences in contaminant metabolism or excretion rates given that both species are closely related genetically (Nunn et al 1996), highly sympatric and known to interbreed (Fisher 1972), and have similar blood protein composition (Brown and Fisher 1966). Previous studies have found comparable PCB congener profile patterns (Jones et al 1996, Guruge et al 2001a as well as PCB metabolite formation (hydroxylated and methylsulfonyl polychlorinated biphenyls) (Klasson-Wehler et al 1998) in Black-footed and Laysan Albatrosses, suggesting these two species metabolize organochlorine compounds in the same way. Organic contaminant concentrations are also heavily influenced by the amount of lipid in the tissue evaluated (Clark et al 1987).…”

“…Similarities in behavioral and breeding ecology between Black-footed and Laysan Albatrosses (Whittow 1993a, b, Tickell 2000 make these reported differences in contaminant body burden surprising. Previous studies have suggested differences in diet are responsible for Black-footed Albatrosses having greater contaminant body burden concentrations than Laysan Albatrosses (Jones et al 1996, Auman et al 1997, Klasson-Wehler et al 1998). However, these papers did not investigate foraging patterns or diet composition.…”

Hydroxylated and Methylsulfonyl Polychlorinated Biphenyl Metabolites in Albatrosses From Midway Atoll, North Pacific Ocean

“…The diet of the Laysan albatross consists primarily of ommastrephid squids (ϳ68% of the diet) whereas the black-footed albatross feed mostly on flying fish (50%) and squids constitute a relatively lesser proportion (32%) of the diet. Details regarding the sources of environmental contaminants for these two species of albatrosses have been reported previously [41,42].…”

Toxaphene and Other Persistent Organochlorine Pesticides in Three Species of Albatrosses From the North and South Pacific Ocean

“…Relatively high concentrations of chlorinated aromatic compounds, including PCBs and their hydroxylated and methyl sulfone metabolites [24], polychlorinated dibenzo-p-dioxins, and dibenzofurans (PCDD/Fs) and non-ortho-substituted PCBs were found in fat samples from the north Pacific populations [25], while lower concentrations were measured in the south Pacific species [23]. Ortho-substituted PCBs and DDT-related compounds were also reported in plasma samples from the north Pacific populations [26].…”