2010年10月12日 星期二
2010年8月29日 星期日
2010年8月6日 星期五
2010年7月31日 星期六
2010年7月24日 星期六
Light Pollution and Ecosystems (ActionBioscience)
豐富的光污染資訊 Rich information about light pollution
Light Pollution and Ecosystems (ActionBioscience)
Oh... Another effect of CO2 on the wildlife!
News: Baby fish clown around with CO2
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Under the influence of a low pH, Nemo went out in search of trouble. Photo: Jeff Kubina |
How does a baby clown fish smell? If levels of carbon dioxide (CO2)continue to rise, the answer might be 'awful'.
According to new research by marine biologists at James Cook University, more CO2 in the ocean appears to make it increasingly difficult for some species of fish larvae to sniff out the bad guys. While it's already understood that a lower pH makes it more difficult for young fish to detect safe refuges using scent, this new research has linked their reduced ability to smell with risky behaviour around predator fish.
Carbon dioxide acts as a greenhouse gas in our atmosphere, scattering heat radiation and making it more difficult for the heat to reflect away into space. In the ocean, however, it creates a different problem; when CO2 dissolves in water, it reacts with the surrounding molecules to create carbonic acid (H2CO3). This is bad news for organisms such as molluscs and coral that use calcium to build protective coverings, since the lower acidity weakens their shells.
This research demonstrates that acidification can interfere with other biochemical processes in unexpected ways. The biologists changed the concentration of acid (pH) in a habitat of clown and damsel fish larvae and watched their behaviour. At a pH 7.8, the fish seemed less able to detect the scent of a predator. Those swimming in an environment of pH 7.6 threw all caution to the wind and actually moved towards the smell.
When the daring young damsel fish were released onto a reef, they spent less time lurking out of sight and more time around hungry hunters, making it more likely they'd become a tasty snack for a passing predator. It isn't well understood precisely how the change in pH interferes with the fish's sense of smell.
For this level of acidification to occur in the wild, the amount of carbon dioxide in the atmosphere would need to roughly double to about 850 parts per million. Without some big reductions in the amount of fossil fuels we burn, it's possible that we might see such a rise by the end of this century.
It's well understood that rising levels of carbon dioxide in our atmosphere can lead to some significant changes to our global climate. Yet the impact of this gas on the chemistry of ecosystems beneath the waves appears to be just as important as its effect on the world above.
More information
Stem cells news
It will be a breakthrough to generate brain cells from skin cells! Come and visit:
http://www.bbc.co.uk/news/10622403
http://www.bbc.co.uk/news/10622403
Website introduction: PBS: Nature: Ocean in Glass
Website with rich information and graphic about ocean world! Try the following site:
http://www.pbs.org/wnet/nature/episodes/oceans-in-glass-behind-the-scenes-of-the-monterey-bay-aquarium/introduction/636/?contactID=159138266&gwkey=GET8WNALJH
http://www.pbs.org/wnet/nature/episodes/oceans-in-glass-behind-the-scenes-of-the-monterey-bay-aquarium/introduction/636/?contactID=159138266&gwkey=GET8WNALJH
2010年6月28日 星期一
20 Things You Didn't Know About... Viruses
Want to know more about virus? Browsing the following web site to find interesting facts about virus!
2010年6月3日 星期四
Field camp
不過, 也真真希望生物組同學能更投入喜愛這一科. 即使未來未必選擇與這科有關的事業, 但生物也真的對我們的生活式式相關!
同學們, 多愛它, 並考好它吧!
2010年3月25日 星期四
2010年3月17日 星期三
Good Luck AL Students!
Dear F7 students,
don't know whether you will receive this message, but just wish you good luck in AL!
Remember, work hard to earn your effort!
Mr. Tung
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