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(单词翻译:双击或拖选)
This is Scientific American — 60-Second Science. I'm Christopher Intagliata.
Winter storms have walloped California this year, and snowpack is piling up. But just a few years back, the state was wrung1 dry by a record-breaking drought. And more dry spells will surely come.
"I think everybody agrees that we need more water resources." Adina Paytan, an oceanographer at the University of California, Santa Cruz. She points out that her home country, Israel, faced the same problem. "Israel had water issues for ever and ever. They don't have water issues anymore because they converted pretty much 90 percent of water use to desalination2."
Ocean desalination hasn't enjoyed as much traction3 in California due to its cost, and because of concerns that the plants would damage coastal4 ecosystems5—both when seawater is sucked in, and when leftover6 super-salty brines are released. Now, writing in the journal Water, Paytan and her team have assessed the environmental impact of the nation's largest plant: the Carlsbad Desalination Plant, north of San Diego.
Here's the good news. Scuba7 dives revealed that the communities of starfish, snails8, sea cucumbers and other creatures that live on the sandy ocean bottom offshore9 have not budged10 since the plant opened in 2015. But the bad news? The plume11 of salty runoff stayed intact much farther out than models predicted, rather than easily blending with closer seawater.
"When you have a pool of salty water that doesn't mix, it prevents oxygen from penetrating12, so it can cause lower oxygen levels close to the bottom and obviously, all the organisms that need oxygen are not going to be happy."
Ecosystems offshore from the Carlsbad plant were already disturbed by cooling water discharge from a power plant at the same site, she says, which could explain why the marine13 life was unfazed. But at more pristine14 sites, especially those rich in biodiversity like kelp forests, a salty plume might do more harm.
The state's already planning more ocean desalination projects up and down the coast. Paytan says her lesson is this: "There's tons of water in the ocean. We can use it but we just have to do it responsibly." First step: updating our models of how salty wastewater behaves offshore. To ensure that our thirst for drinking water doesn't cause an ecological15 sea change.
Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.
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wrung
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绞( wring的过去式和过去分词 ); 握紧(尤指别人的手); 把(湿衣服)拧干; 绞掉(水) | |
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desalination
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n.脱盐(作用) | |
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traction
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n.牵引;附着摩擦力 | |
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coastal
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adj.海岸的,沿海的,沿岸的 | |
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ecosystems
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n.生态系统( ecosystem的名词复数 ) | |
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leftover
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n.剩货,残留物,剩饭;adj.残余的 | |
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scuba
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n.水中呼吸器 | |
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snails
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n.蜗牛;迟钝的人;蜗牛( snail的名词复数 ) | |
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offshore
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adj.海面的,吹向海面的;adv.向海面 | |
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budged
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v.(使)稍微移动( budge的过去式和过去分词 );(使)改变主意,(使)让步 | |
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plume
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n.羽毛;v.整理羽毛,骚首弄姿,用羽毛装饰 | |
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penetrating
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adj.(声音)响亮的,尖锐的adj.(气味)刺激的adj.(思想)敏锐的,有洞察力的 | |
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marine
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adj.海的;海生的;航海的;海事的;n.水兵 | |
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pristine
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adj.原来的,古时的,原始的,纯净的,无垢的 | |
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ecological
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adj.生态的,生态学的 | |
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