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Narrator: Listen to part of a lecture in an Environmental Conservation class.
請聽環境保護課上的部分內容。
Professor: Next I want to talk about the collapse of the North American Cod population.
教授：接下來我想講一講北美洲鱈魚數量的爆減。
Let's look at Cape Cod in the northeastern United States.
我們來看看美國東北部的科德角吧。
The area was named Cape Cod because there was so many Cod fish in the waters just off its shores, so many that the first Europeans who fished there in the 17th century reported it was better than in New Finland, Canada.
這個地方被命名為科德角是因為那里海岸邊的水域中曾經有很多鱈魚，數量多到17世紀第一批在那里捕魚的歐洲人報告說那里比加拿大的New Finland還要好。
At the time, New Finland's Cod fishery was so rich that people said it was possible just to lower a bucket in the water, pull it out and it would be full of cod.
在那時，New Finland的鱈魚漁業非常豐富，以至于人們說直接把一個籃子放到水里然后把它拉出來里面就會裝滿鱈魚也是有可能的。
But Cape Cod was even better, so the fishing industry there did great until after the 1940s, um, there were simply too many fishing vessels, sophisticated vessels, competing for fewer and fewer fish.
但是科德角還要更好，所以那里的捕魚業發展得一直很好，直到二十世紀四十年代，那里的漁船太多了，都是很有經驗的漁船來爭搶越來越少的魚。
In the 1940s there were still about four hundred million pounds of fish caught at Cape Cod every year.
在二十世紀四十年代，科德角每年仍有大約4億磅的魚被捕撈。
Just 50 years later, though, by the 1990s, commercial cod fishing there had become unprofitable.
但是，僅僅在50年后，也就是二十世紀九十年代，商業捕撈鱈魚在那里已經無利可圖了。
The annual catch had gone down about 5% of its 1940s' level.
年捕獲量下降到了四十年代水平的5%左右。
And here's what's so fascinating: as more and more fishing vessels with better and better fishing technology were competing for cod, this competition was causing changes to the biology of the fish and these changes were making it more and more difficult for the cod population to sustain itself.
很令人著迷的是：隨著越來越多的裝配著越來越好的捕魚技術的漁船爭搶鱈魚，這種競爭導致這種魚產生了生物變化，而這些變化使得鱈魚群越來越難維持自己的生存。
Student: Changes to the biology of the fish?
學生：這種魚發生了生物變化？
Professor: Well, if a cod fish could reproduce earlier than usual, it'd have a better chance of passing on its genes to the next generation before being caught, right?
教授：如果一條鱈魚能比平常早一些繁殖，那它在被抓之前就有更好的機會把自己的基因傳給下一代，對嗎？
And sure enough, biologists noticed that around Cape Cod, the cod were beginning to mature at an earlier age than normal.
果不其然，生物學家發現在科德角附近，鱈魚在比一般更早的年紀開始成熟。
Prior to the population collapse, cod usually took about 8 to 10 years to fully mature, to start to reproduce, and they lived around 40 years total.
在數量爆減之前，鱈魚通常需要8-10年的時間才能完全成熟，才能開始繁殖，而且它們總共能活40年左右。
So cod had about 30 years of active reproductive life.
所以之前的鱈魚有大概30年的時間可以積極地繁殖后代。
But now, cod were beginning to reproduce at a younger age, at 3 to 4 years old, and they were living shorter lives because they were being caught, so they had fewer years within which to reproduce.
但是現在，鱈魚在一個更年輕的年紀，在3-4歲的時候就開始繁殖，而且因為會被捕獲，它們的生命也變得更短，所以它們能繁殖的年數更少了。
