Melting Glaciers: A Probable Source of DDT to the Antarctic Marine Ecosystem

Abstract

Persistent organic pollutants reach polar regions by long-range atmospheric transport and biomagnify through the food web accumulating in higher trophic level predators. We analyzed Adélie penguin (Pygoscelis adeliae) samples collected from 2004 to 2006 to evaluate current levels of ∑DDT (p,p′-DDT + p,p′-DDE) in these birds, which are confined to Antarctica. Ratios of p,p′-DDT to p,p′-DDE in Adélie penguins have declined significantly since 1964 indicating current exposure to old rather than new sources of ΣDDT. However, ∑DDT has not declined in Adélie penguins from the Western Antarctic Peninsula for more than 30 years and the presence of p,p′-DDT in these birds indicates that there is a current source of DDT to the Antarctic marine food web. DDT has been banned or severely restricted since peak use in the 1970s, implicating glacier meltwater as a likely source for DDT contamination in coastal Antarctic seas. Our estimates indicate that 1−4 kg·y−1 ΣDDT are currently being released into coastal waters along the Western Antarctic Ice Sheet due to glacier ablation.

Organochlorine Pollutants in Western Antarctic Peninsula Sediments and Benthic Deposit Feeders

“…Lipids are considered as the major accumulation compartments in biota for lipophilic PCBs and OCPs (48) . (24,29,30,33) , this is the first comprehensive report on PCB and OCP concentrations in benthic holothurians at the Western Antarctic Peninsula.…”

“…North Atlantic Deep Water from 47°N to 30°S is about 150 years (25 ~ 300 years) and another 95 years (25 ~ 422 years) from 30°S to the Southern Ocean (13,14) Since the first detection of PCBs and organochlorine pesticides (OCPs) in the Antarctic five decades ago (15,16) , there have been dozens of investigations on the occurrence, distribution of POPs in Antarctic air (17)(18)(19)(20) , water (8,21) , soil (2,4) , sediments (22,23) , and biota (24)(25)(26)(27)(28)(29)(30)(31)(32)(33) . Most of the studies were conducted at the tip of the Western Antarctic Peninsula (WAP) and Ross Sea area (2,6) .…”

Assessment of persistent organic pollutants and their relationship with immunoglobulins in blood of penguin colonies from Antarctica

“…It is well known that the production of POPs was stopped some decades ago (Geisz et al 2008), and for that reason there has been a reduction in the levels of some POPs in Antarctica ( Van den Brink et al 2011). In concordance with that, our levels of HCB were lower than those reported by Corsolini et al (2007) in blood of Pygoscelis penguins.…”

“…The immune system is the main defense mechanism of an organism against aggressive agents, thus individuals with developed immunity are most able to survive in harsh conditions (French et al 2009). Even though the production of persistent organic pollutants (POPs) has been banned for over 35 years, their levels still remain in the environment, and because they can be transported by wind and water, their effects can be evidenced far from where they were released, even reaching cold regions (Geisz et al 2008). Polychlorinated biphenyls (PCBs) and chlorinated pesticides (such as DDT, hexachlorobenzene, endosulfans) are toxic xenobiotics that adversely can affect people, wildlife and ecosystems (Bright et al 1995, Roosens et al 2007, Llansola et al 2010.…”

DDT Strikes Back: Galapagos Sea Lions Face Increasing Health Risks

“…The apparent increase of DDT levels in remote Galapagos sea lions is not an isolated event since concentrations of DDT in Adélie penguins (Pygoscelis adeliae) from remote areas of the western Antarctic Peninsula have not decreased between 2004(Geisz et al 2008. Likewise, concentrations of DDT in human breast milk from Japan have not decreased since 1998 (Kunisue et al 2006).…”