STRANGLING ON GASES

You don't believe in the greenhouse effect? Check out the plankton.

Scientists: Gases “strangling’ southern ocean
February 24, 2007 (Reuters via CNN)

- The pristine Southern Ocean, which swirls around the Antarctic and absorbs vast amounts of carbon dioxide from the atmosphere, is slowly losing a fight against industrial gases…
- The Southern Ocean's unique wind and storm conditions make it the world's greatest carbon "sink"; the earth's oceans absorb a third of the carbon dioxide in the atmosphere, and the Southern Ocean absorbs a third of that.
- But the waters that surround Antarctica are becoming more acidic as they absorb increasing amounts of carbon dioxide…The more acidic an ocean gets, the less carbon dioxide it can soak up…
- [Dr Will Howard of Australia's Antarctic Climate and Ecosystems Cooperative Research Centre] has just returned to the Australian Antarctic and Southern Ocean Research Program's base in southern Tasmania state after leading a team of 60 international scientists on a five-week expedition…"I would not say it's being killed," Howard said…But it is being changed. "And once the system is altered ... it's going to be a different ecosystem…"

- Rising acidification of the Southern Ocean has already begun to affect the ability of plankton -- microscopic marine plants, animals and bacteria -- to absorb carbon dioxide…plants absorb carbon dioxide from the atmosphere through photosynthesis…and sink it to the depths.
- Microscopic marine organisms also form tiny shells of calcium carbonate, which sink when they die to also move carbon to the bottom…
Projections by the…Research Centre indicate that some organisms will not be able to make shells within the next 100 years…"We're talking about time scales of decades to perhaps a century…"

- …east of Tasmania, where the warm, east Australian current mixes with colder Southern Ocean waters…is also an area that carries iron-bearing dust blown off the vast, arid Australian continent into the sea. And iron is seen as part of a possible solution.
- Scientists have discovered that phytoplankton in the Southern Ocean are deficient in iron, and that some parts of the Southern Ocean are persistently more fertile than others, probably because they receive extra iron…
- Australia, the world's largest exporter of iron ore…[might]throw its iron ore into the sea to help plankton absorb [but]…”It's not so easy to manipulate," Howard said.