VOA常速英语2015--浮游生物的粪便帮助科学家预测气候变化（在线收听）

Plankton Poop May Help Scientists Predict Climate Changes 浮游生物的粪便帮助科学家预测气候变化

Scientists trying to predict future changes in our climate are using every possible source of data to make their calculations. Lately, they have learned that one of the most sensitive instruments could be floating right in front of them - tiny clumps of organic matter that drift in the ocean.

科学家试图利用各种可能利用的数据来源来进行计算，预测地球气候的未来变化。最近，科研人员了解到，最敏感的仪器之一可能就飘浮在他们面前，那就是在海洋随波逐流的有机物质的细小碎块。

As if materializing from a different dimension, the submersible device called PELAGRA (PElagic LAGRAngian sediment trap) slips below the surface and sinks into a research pool at the National Oceanography Centre, in Southampton, England.

这部潜在水下的设备仿佛来自另一个空间维度，它叫做PELAGRA （“水层拉格朗日”沉积物搜集器）。它滑入水下，沉入英格兰南安普顿的国家海洋中心的一座研究池内。

Soon, two such devices will be deployed to the South Atlantic to collect samples of so-called ‘marine snow.’

很快，两部这样的设备将部署到南大西洋，搜集被称为“海洋雪”（Marine Snow）的样本。

“Marine snow is composed of dead phytoplankton which sort of clump together to form flakes and then they're heavy enough to sink down into the deep ocean. It can also be formed of little animals which eat the little plants and then they poop out that carbon, and then their fecal pellets are very heavy and they sink down to the bottom of the ocean, also carrying lots of carbon with them," said biogeochemist Stephanie Henson.

国家海洋中心的生物地球化学专家史蒂芬妮·汉森说：“海洋雪由死亡的浮游植物组成，它们聚到一起，形成雪花状，积累到一定重量之后，就会沉到深海。它还可以由小动物组成，这些小动物吃小植物，然后把那种碳物质拉出来，它们的小粪粒很重，沉到海底，也含有很多碳。”

Although invisible to the naked eye, phytoplankton are so abundant that they are responsible for half of all the carbon absorbing photosynthetic activity on earth.

虽然肉眼看不见，但浮游植物大量存在，在所有吸收碳的地球光合活动中，有一半来自它们。

Understanding that process could help scientists create more advanced computer models of global environmental changes.

了解这一程序可能帮助科学家建立更先进的计算机模型，推算全球环境变化。

The challenge was to build a submersible device that could float between 50 and 500 meters deep. That's where scientists say all this carbon is being absorbed, and beginning its journey to the bottom of the sea.

难题是建造一个潜入水下的仪器，可以在50米到500米之间的水中漂浮。科学家说，所有的碳都是在这层深度被吸收的，然后，向海底进发。

“The way that we do that is by putting them in tanks of water... and adding weights until they're just sinking; at which point we know they have the same density as the water that they're sitting in," said Project Leader Richard Sanders.

项目带头人理查德·桑德斯说：“我们的方式是把它们放置在水箱中，然后增加重量，直到他们进入悬浮状态；在那一刻，我们就知道它们的密度和周围水的密度是一样的。”

PELAGRA will suck ocean water with marine snow into containers and periodically bring them to the surface for detailed study.

PELAGRA将把含有海洋雪的海水吸入容器，并定期把它们带出水面，以供仔细研究。

Scientists hope that PELAGRA devices will help them answer another interesting question - why is marine snow more abundant in some parts of the ocean than in others.

科研人员希望，PELAGRA将帮助他们回答另一个有趣的问题：为什么某些海域的海洋雪比另一些海域要多？