Web Release Date: April 30,
Melting Glaciers: A Probable Source of DDT to the Antarctic Marine Ecosystem
Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, Virginia 23062, Polar Oceans Research Group, Sheridan, Montana 59749, and Ecosystems Center, Marine Biological Laboratory, Woods Hole, Massachusetts 02543
Received for review November 21, 2007
Revised manuscript received February 29, 2008
Accepted March 18, 2008
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.
