What’s so great about the Great Lakes? - Cheri Dobbs and Jennifer Gabrys

翻译人员: Meihan Zhao 校对人员: Guanguan Ke

What's so great about the Great Lakes?

是什么让五大湖如此伟大？

They're known as America's inland seas.

它也被称作美国的内海

The North American Great Lakes

北美五大湖

Huron,

休伦湖，

Ontario,

Michigan,

安大略湖，

密歇根湖

Erie,

伊利湖

and Superior

以及苏必利尔湖，

are so massive that they border eight states

它们非常宏大，构成八个州的边界，

and contain 23 quadrillion liters of water.

包含23千万亿公升水，

That's enough to cover the land area of the contiguous United States

即使将美国国土全部覆盖，

three meters deep.

水位仍可达三米深。

These vast bodies of water span forest,

这片广阔的水域跨越森林，

grassland,

and wetland habitats,

草原，

和湿地生态系统，

supporting a region that's home to over 3,500 species.

供养着超过3500种生物。

But how did such a vast and unique geological feature come to be?

但是，这片广阔而独特的地质特征 是如何形成的呢？

The story begins near the end of the last ice age over 10,000 years ago,

故事要从上个冰河世纪的末期说起， 也就是超过1万年以前，

a time when the climate was warming

气候转暖，

and the glaciers that cloaked the Earth's surface began their slow retreat.

地球表面的冰川缓缓融化，

These immense ice sheets carved out a series of basins.

无垠冰川曾雕刻出形态各异的盆地，

Those basins filled with water as the ice began to melt,

冰雪融化后，雪水流入盆地，

creating the world's largest area of freshwater lakes.

创造出了世界上最大的淡水湖。

Over time, channels developed between these basins,

不久，盆地间的河道凸显，

and water began to flow in an ongoing exchange

湖水流入并相互交融

that persists to this day.

一直到今日。

In fact, today, the interconnected Great Lakes

事实上，今天，这些相互交融的五大湖，

contain almost 20% of the world's supply of fresh surface water.

包含了几乎世界上20%的淡水供应。

The water's journey begins in the far north of Lake Superior,

水的旅程起始于最北部的苏必利尔湖，

which is the deepest, coldest, and clearest of the lakes,

也是最深、最冷、最干净的湖，

containing half the system's water.

包含了整个五大湖系统一半的水。

Lake Superior sinks to depths of 406 meters,

苏必利尔湖最深处可达406米，

creating a unique and diverse ecosystem that includes more that 80 fish species.

创造了独一无二的多样的生态系统， 包含80多种鱼，

A given drop of water spends on average 200 years in this lake

一滴水平均需要200年

before flowing into Lake Michigan or Lake Huron.

才能从这里流入密歇根湖或休伦湖

Linked by the Straits of Mackinac, these two lakes are technically one.

在麦基诺海峡的连接下，这两大湖实际是一体的

To the west lies Lake Michigan,

西边是密歇根湖，

the third largest of the lakes by surface area.

水域面积世界第三，

Water slowly moves through its cul-de-sac shape

水沿着“死胡同”缓缓流回，

and encounters the world's largest freshwater dunes,

沿途经过世界最大的淡水滩

many wildlife species,

数不清的野生物种

and unique fossilized coral.

和独特的珊瑚化石

To the east is Lake Huron, which has the longest shoreline.

东边是享有最长海岸线的休伦湖，

It's sparsely populated, but heavily forested,

那里人口稀少，植被丰富

including 7,000-year-old petrified trees.

7000年的石化树也长于此地，

Below them, water continues to flow southeastwards

植被下，湖水沿东南继续流淌

from Lake Huron into Lake Erie.

流出休伦湖便进入伊利湖

This lake's status as the warmest and shallowest of the five

作为五大湖中最温暖、也是最浅的地方，

has ensured an abundance of animal life, including millions of migrating birds.

这里物种丰富，上百万候鸟迁徙来此

Finally, the water reaches its last stop by dramatically plunging

最后，水流至最后一站

来到振聋发聩的尼亚加拉瀑布， 经过超过50米的猛烈下冲，

more than 50 meters down the thundering Niagara Falls

into Lake Ontario, the smallest lake by surface area.

进入安大略湖——表面积最小的湖。

From there, some of this well-traveled water enters the St. Lawrence River,

至此，这滴水经历漫长旅程，流入圣劳伦斯河，

eventually reaching the Atlantic Ocean.

并最终汇入大西洋。

In addition to being a natural wonder,

除了作为自然景观，

the perpetually flowing Great Lakes bring us multiple benefits.

五大湖日复一日流动着，为人类带来不少福利。

They provide natural water filtration,

它提供了天然水过滤、

flood control,

洪水控制、

and nutrients cycling.

以及营养循环。

By moving water across more than 3,200 kilometers,

随着湖水超过3200千米的移动，

the Great Lakes also provide drinking water for upward of 40 million people

五大湖也给上游4千万居民提供了饮用水，

给沿岸的工厂和农庄

and 212 billion liters a day for the industries and farms

每天带来2120亿公升水。

that line their banks.

But our dependence on the system is having a range of negative impacts, too.

但是，我们对五大湖的依赖 也造成了一系列负面效果

The Great Lakes coastal habitats are being degraded and increasingly populated,

五大湖沿岸生态栖息地逐渐退化， 被越来越多的人口侵蚀，

exposing the once pristine waters

曾经原生态的水域，

to industrial, urban, and agricultural pollutants.

暴露给工厂、城市和农业的污染物。

Because less than 1% of the water leaves the Lake's system annually,

由于每年仅有1%的水能离开这个系统，

decades-old pollutants still lurk in its waters.

数十年的旧物染污仍然会逗留在水域中。

Humans have also inadvertently introduced

人类也无意间向湖中引进了

more than 100 non-native and invasive species into the lakes,

超过100种非原生的入侵物种，

such as zebra and quagga mussels, and sea lampreys

例如两种斑纹贝（Zebra and quagga mussels）和七鳃鳗

that have decimated some indigenous fish populations.

它们已经使一些土著鱼类灭绝。

On a larger scale, climate change is causing the waters to warm,

更大程度上讲，气候的变化让这里的水越来越温暖

thus reducing water levels and changing the distribution of aquatic life.

使水位下降，造成水生物分布的改变

Luckily, in recent years, governments have started to recognize the immense value

幸运的是，近几年，政府部门开始意识到

of this natural resource.

这项自然资源的巨大价值

Partnerships between the United States and Canada are underway to reduce pollution,

美国和加拿大开始联手治理污染、

protect coastal habitats,

保护生态栖息地，

and halt the spread of invasive species.

并阻止入侵物种的扩散。

Protecting something as massive as the Great Lakes system

保护像五大湖这么大的生态系统，

will require the collaboration of many organizations,

需要许多组织的合作参与。

but the effort is critical

但是要想保住这个流动着的内陆奇迹，

if we can preserve the wonder of this flowing inland sea.

这项工作势在必行。