Toxic anthropogenic signature in Antarctic continental shelf and deep sea sediments

Abstract

Industrial activity generates harmful substances which can travel via aerial or water currents thousands of kilometers away from the place they were used impacting the local biota where they deposit. The presence of harmful anthropogenic substances in the Antarctic is particularly surprising and striking due to its remoteness and the apparent geophysical isolation developed with the flows of the Antarctic Circumpolar current and the ring of westerly winds surrounding the continent. However, long-range atmospheric transport (LRAT) of pollutants has been detected in the Antarctic since the 70’s along the Antarctic trophic food web from phytoplankton to birds. Still, no information exists on the presence of cytotoxic compounds in marine sediments neither at basin scales (thousands of kilometers) nor in water depths (hundreds of meters) beyond shallow coastal areas near research stations. Our results showed for the first time that there is cytotoxic activity in marine sediment extracts from water depths >1000 m and along thousands of kilometers of Antarctic continental shelf, in some cases comparable to that observed in Mediterranean areas. Ongoing anthropogenic pressure appears as a serious threat to the sessile benthic communities, which have evolved in near isolation for millions of years in these environments.

Emerging contaminants and priority substances in marine sediments from Cartagena Bay and the Grand Marsh of Santa Marta (Ramsar site), Colombia

“…The cytotoxic activity in marine sediment extracts has been studied using different cell lines (Caballero-Gallardo et al, 2015 ; Isla et al, 2018 ; Kocan et al, 1985 ). A reduction in cell viability (26–48%) was observed in cells exposed to 1% extracts from stations S2, S3, S4, S15, S6, and S9.…”

Antarctic ecosystems in transition – life between stresses and opportunities

“…The Antarctic is an environmental sink for anthropogenic bio-accumulative POPs and heavy metals, reaching atmospheric, marine (from sea surface to the deep sea) and terrestrial environments (Isla, Pérez-Albaladejo & Porte, 2018). Biomagnification of toxic polychlorinated biphenyls (PCBs) has been reported across marine foodwebs.…”

Environmental contamination and climate change in Antarctic ecosystems: an updated overview

“…van den Brink et al 120 found decreasing trends in PCBs, HCB and dieldrin levels in Adélie penguins, southern fulmars and pelagic fish from 1993–1994 to 2003–2004, even though their concentrations were steady or increasing in benthic organisms; thus, they questioned whether the POPs contamination in Antarctica is actually declining. Isla et al 121 detected cytotoxic activity in extracts of marine sediments collected along thousands of kilometers of the Antarctic continental shelf and up to 1200 m depth. However, some more recent works would seem to indicate a decreasing trend of long-range transport and bioavailability of POPs in the Antarctic environment.…”