Legacy and Emerging Persistent Organic Pollutants in Antarctic Benthic Invertebrates near Rothera Point, Western Antarctic Peninsula

Abstract

Pollutant levels in polar regions are gaining progressively more attention from the scientific community. This is especially so for pollutants that persist in the environment and can reach polar latitudes via a wide range of routes, such as some persistent organic pollutants (POPs). In this study, samples of Antarctic marine benthic organisms were analyzed for legacy and emerging POPs (polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides) to comprehensively assess their current POP concentrations and infer the potential sources of the pollutants. Specimens of five benthic invertebrate species were collected at two distinct locations near Rothera research station on the Antarctic Peninsula (67°35'8 ̋ S and 68°7'59 ̋ W). Any impact of the nearby Rothera station as a local source of pollution appeared to be negligible. The most abundant chemicals detected were hexachlorobenzene (HCB) and BDE-209. The highest concentrations detected were in limpets and sea urchins, followed by sea stars, ascidians, and sea cucumbers. The relative congener patterns of PCBs and PBDEs were similar in all of the species. Some chemicals (e.g., heptachlor, oxychlordane, and mirex) were detected in the Antarctic invertebrates for the first time. Statistical analyses revealed that the distribution of the POPs was not only driven by the feeding traits of the species but also by the physicochemical properties of the specific compounds.

Figure 1

Map of the northeastern part of Ryder Bay with sampling locations. Site Islands (A) will principally only receive POPs by LRAT, while site Station (B) has the potential for additional contamination from the research station and air and shipping activities.

Figure 2

Boxplot of total concentrations of PCBs in pg/g Lw. The “n” quoted above denotes the number of pooled samples analyzed. The mid-line of each plot indicates the median value, the box the interquartile (25–75%) range, and the whiskers the 95% percentile. Black dots are the original data, with black square crosses representing outliers. The plots with the same gray letter indicate no statistically significant differences.

Figure 3

Boxplot of total concentrations of PBDEs in pg/g Lw. The n quoted above denotes the number of pooled samples analyzed. The mid-line of each plot indicates the median value, the box the interquartile (25–75%) range, and the whiskers the 95% percentile. Black dots are the original data, with black square crosses representing outliers. The plots with the same gray letter indicate no statistically significant differences.

Figure 4

OCP concentrations in five Antarctic benthic species in pg/g Lw. The mid-line of each plot indicates the median value, the box shows the interquartile range, and the whiskers are the 95% percentile range. The blank spaces indicate no data, as all measurements were below the detection limit.

Figure 5

Bi-plot of dc-PCA-related concentrations of POPs (green arrows) and species (red dots) (λ1 = 0.19 and λ2 = 0.06).

Figure 6

Bi-plot of dc-PCA-related species (red dots) and properties of POPs (blue arrows) (λ1 = 0.059 and λ2 = 0.026).