字神帝國英語天地

今日主題：Beaver Dams Strengthened by Humans Help Fish Rebound / 人工加固海狸壩可使魚類數量回升

洪欣老師推薦：托福聽力最好的課外教材：60-Second Science

康康精選托福會考的主題，堅持每天精聽一定會進步的哦!!

建議方法：
1. 先聽兩三遍 (不看文稿)
2. 再一句一句聽寫 (每句都要聽寫數遍，直到寫出85%以上的字)
3. 最後check文稿，看哪聽不出來，單字沒背過，還是發音不熟。
4. 堅持天天聽，就能每天進步哦。

MP3音檔 (按右鍵可下載聽)：喜歡的同學，幫忙推或按讚哦~~
http://online1.tingclass.net/voaspe/…/20160728sa_science.mp3

只有音檔怎夠，聽不懂地方，不用怕，康康幫你準備好中英文稿了：

中英文稿：
In the early 19th century the fur industry reached what was then known as the Oregon Territories. Lewis and Clark found massive numbers of Pacific salmon and steelhead trout there, swimming among the beaver dams scattered across the Columbia River Basin.
19世紀初期，皮毛生產行業在俄勒岡州興起，以生產海狸皮毛聞名。在哥倫比亞河盆地的海狸水壩游泳時，Lewis和Clark在這兒發現了大量的太平洋鮭魚和和虹鱒魚。

But in an effort to starve American interests, Canada’s Hudson's Bay Company tried to create a "fur desert" by killing off as many fur-bearing animals as they could. As a result, beavers had all but disappeared from the area by the year 1900. And once the beavers and their dams were gone, fish populations dropped.
但為了爭奪美國利益，加拿大哈德遜灣公司試圖通過盡可能的殺死更多皮毛動物，來創建一個“皮毛沙漠”，結果到1900年，海狸消失殆盡。並且一旦海狸和它們建造的水壩都消失了，魚類的數量將會下降。

Today, steelhead trout numbers in the region continue to fall. But scientists and government agencies are working to restore their habitats.
如今，該地區虹鱒的數量繼續下降。但科學家和政府機構正在共同努力修復它們的棲息地。

"We're looking for restoration approaches in these areas to recover ESA-listed species, but we really don't know what works and what doesn't." Nick Bouwes of the environmental consulting firm Eco Logical Research and Utah State University.
“在這些地區，我們正在尋找修復方法，以恢復這些物種。但我們真的不知道什麼方法可行，什麼方法不可行。”環境諮詢公司生態邏輯研究和猶他州立大學的Nick Bouwes表示。

He says that the U.S. spends a billion dollars each year to restore watersheds, but without any real empirical information to guide those efforts. So Bouwes and his team tested the idea that by helping beavers, they could help the fish.
Dams naturally alter the flow of streams, providing fish with a variety of suitable habitats. But the watersheds have become so degraded that there's not enough woody vegetation available for the beavers to build strong dams. The flimsy ones they do build get washed away whenever there's a big storm.
他表示每年美國花十億美元來修復流域，但沒有任何實際經驗來指導這些工作。因此 Bouwes和他的團隊對通過幫助海狸，進而幫助魚類的設想進行了驗證。大壩自然改變了源源溪流，從而為魚類提供各種合適的棲息地。但水域的惡化使得沒有足夠的木本植物供海狸用來建造堅固的水壩。每當有大風暴時，它們所建造的脆弱的水壩就會被沖走。

"The idea was, can we reinforce these dams so that they maintain their integrity during high flows, and can be maintained by beavers to capture that sediment, to reconnect that floodplain?"
“當時的想法是，我們是否可以加固這些海狸壩，這樣有洪流時就可以保存它們的完整性，並且是否海狸可以對其進行維護，截留沉積物，使其與河漫灘重新連接起來。”

For seven years, the researchers compared Bridge Creek, which had lots of artificially strengthened dams, to Murderer's Creek, which had none. And in Bridge Creek, the fish flourished—despite the view held by some that beaver dams are bad for fish. The results are in the journal Scientific Reports. [Nicolaas Bouwes et al, Ecosystem experiment reveals benefits of natural and simulated beaver dams to a threatened population of steelhead (Oncorhynchus mykiss)]
七年來，研究人員們將兩者進行了對比，前者擁有許多人為加固的大壩，而後者一座也沒有。在Bridge Creek，魚類生長繁榮——儘管一些人所持的觀點為：海狸建造的水壩對魚類有害。該項研究結果發表在《科學》雜誌上。

"Beavers, they’re really good at making a mess of a system, and it's that messiness that's exactly what we're looking for, by creating more complex fish habitat."
“海狸，它們真的很擅長把一個系統弄得一團糟。並且，這些混亂正是我們所尋找的。通過創建更複雜的魚類的棲息地。”

And costing just $11,000 for each kilometer of stream, artificial dam reinforcements are much cheaper than conventional restoration methods—since the beavers do most of the work for us. And that is a dam good deal.
並且，每公里溪流整治僅需花費11,000 美元，人工加固大壩比傳統修復方法更加便宜。因為海狸為我們做了大部分的工作。並且這是一個非常好的交易。