Communist
16th February 2010, 19:35
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Rising acid levels pose growing risk to marine life (http://www.smh.com.au/environment/rising-acid-levels-pose-growing-risk-to-marine-life-20100215-o2vj.html)
February 16, 2010
LONDON: The oceans are becoming acidic at a faster rate than at any time in the past 65 million years, threatening marine life and food supplies, according to a new study.
Researchers from the University of Bristol found that when ocean acidification accelerated, it caused extinction at the bottom of the food chain.
The current acidification was being caused by carbon dioxide from cars and factories, which was absorbed by the water.
Since the Industrial Revolution, acidity in the seas has increased by 30 per cent.
The last time such a fast change occurred was thought to be 65 million years ago, when a natural event caused ocean acidification.
The study looked at sediment from about 55 million years ago, when acidification was occurring. It found widespread extinction of tiny organisms.
Andy Ridgwell, the lead author of the paper, published in Nature Geoscience (see article below), said acidification was occurring much faster today than in the past, ''exceeding the rate at which plankton can adapt'' and threatening the basis of much marine life.
This would mean fish and other creatures further up the food chain that humans eat may be affected as soon as the end of this century, he said. **
Telegraph, London
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(http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo755.html)Past constraints on the vulnerability of marine calcifiers to massive carbon dioxide release (http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo755.html)
by Andy Ridgwell (http://74.125.47.132/search?q=cache%3AOnU62dTFeD4J%3Awww.ggy.bris.ac.uk %2Fpersonal%2FAndyRidgwell%2Fmiscellaneous%2Fbio.p df+Andy+Ridgwell&hl=en&gl=us) & Daniela N. Schmidt (http://www.gly.bris.ac.uk/people/DNS.html)
(http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo755.html#top)Increasing concentrations of carbon dioxide in sea water are driving a progressive acidification of the ocean.
Although the associated changes in the carbonate chemistry of surface and deep waters may adversely affect marine calcifying organisms, current experiments do not always produce consistent results for a given species.
Ocean sediments record past biological responses to transient greenhouse warming and ocean acidification. During the Palaeocene–Eocene thermal maximum, for example, the biodiversity of benthic calcifying organisms decreased markedly, whereas extinctions of surface dwellers were very limited.
Here we use the Earth system model GENIE-1 to simulate and compare directly past and present environmental changes in the marine realm.
In our simulation of future ocean conditions, we find an undersaturation with respect to carbonate in the deep ocean that exceeds that experienced during the Palaeocene–Eocene thermal maximum and could endanger calcifying organisms.
Furthermore, our simulations show higher rates of environmental change at the surface for the future than the Palaeocene–Eocene thermal maximum, which could potentially challenge the ability of plankton to adapt.
____________
Rising acid levels pose growing risk to marine life (http://www.smh.com.au/environment/rising-acid-levels-pose-growing-risk-to-marine-life-20100215-o2vj.html)
February 16, 2010
LONDON: The oceans are becoming acidic at a faster rate than at any time in the past 65 million years, threatening marine life and food supplies, according to a new study.
Researchers from the University of Bristol found that when ocean acidification accelerated, it caused extinction at the bottom of the food chain.
The current acidification was being caused by carbon dioxide from cars and factories, which was absorbed by the water.
Since the Industrial Revolution, acidity in the seas has increased by 30 per cent.
The last time such a fast change occurred was thought to be 65 million years ago, when a natural event caused ocean acidification.
The study looked at sediment from about 55 million years ago, when acidification was occurring. It found widespread extinction of tiny organisms.
Andy Ridgwell, the lead author of the paper, published in Nature Geoscience (see article below), said acidification was occurring much faster today than in the past, ''exceeding the rate at which plankton can adapt'' and threatening the basis of much marine life.
This would mean fish and other creatures further up the food chain that humans eat may be affected as soon as the end of this century, he said. **
Telegraph, London
========================
(http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo755.html)Past constraints on the vulnerability of marine calcifiers to massive carbon dioxide release (http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo755.html)
by Andy Ridgwell (http://74.125.47.132/search?q=cache%3AOnU62dTFeD4J%3Awww.ggy.bris.ac.uk %2Fpersonal%2FAndyRidgwell%2Fmiscellaneous%2Fbio.p df+Andy+Ridgwell&hl=en&gl=us) & Daniela N. Schmidt (http://www.gly.bris.ac.uk/people/DNS.html)
(http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo755.html#top)Increasing concentrations of carbon dioxide in sea water are driving a progressive acidification of the ocean.
Although the associated changes in the carbonate chemistry of surface and deep waters may adversely affect marine calcifying organisms, current experiments do not always produce consistent results for a given species.
Ocean sediments record past biological responses to transient greenhouse warming and ocean acidification. During the Palaeocene–Eocene thermal maximum, for example, the biodiversity of benthic calcifying organisms decreased markedly, whereas extinctions of surface dwellers were very limited.
Here we use the Earth system model GENIE-1 to simulate and compare directly past and present environmental changes in the marine realm.
In our simulation of future ocean conditions, we find an undersaturation with respect to carbonate in the deep ocean that exceeds that experienced during the Palaeocene–Eocene thermal maximum and could endanger calcifying organisms.
Furthermore, our simulations show higher rates of environmental change at the surface for the future than the Palaeocene–Eocene thermal maximum, which could potentially challenge the ability of plankton to adapt.
____________