Glaciers releasing chemical cocktails
Marine biologist Heidi Geisz of the Virginia Institute of Marine Science in the USA, led a team that sampled DDT levels in penguins. A 1964 survey found small amounts in the penguins, and because worldwide use of the pesticide has plummeted – from 40,000 tonnes per year in 1980 to 1,000 tonnes per year currently – she expected to find a comparable drop in the penguins.
Instead, she found similar levels of DDT and low levels of DDE (the chemical that DDT breaks down into as it works its way up the food chain), suggesting there was a new source of DDT in the area. She concluded that the DDT was seeping out of the glaciers, which grew during the 1950s and ’60s but are now melting faster than they grow.
The levels of DDT in the area shouldn’t harm the penguins, but Geisz is concerned that the glaciers might release other, more dangerous chemicals.
‘DDT is not the only chemicals that these birds are ingesting and it’s certainly not the worst,’ Geisz told New Scientist.
July 2008
Instead, she found similar levels of DDT and low levels of DDE (the chemical that DDT breaks down into as it works its way up the food chain), suggesting there was a new source of DDT in the area. She concluded that the DDT was seeping out of the glaciers, which grew during the 1950s and ’60s but are now melting faster than they grow.
The levels of DDT in the area shouldn’t harm the penguins, but Geisz is concerned that the glaciers might release other, more dangerous chemicals.
‘DDT is not the only chemicals that these birds are ingesting and it’s certainly not the worst,’ Geisz told New Scientist.
July 2008
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