一角鲸是一种头上长有长牙的海洋哺乳动物。专家表示，随着气候变暖，海冰融化，船舶航线增多，海洋噪声增加，到2025年，一角鲸有可能会因海洋噪音污染而灭绝。本期 “随身英语” 介绍这种被人称作 “海洋独角兽” 的动物所面临的生存威胁。

词汇：marine animals 海洋动物

Of all the creatures on the planet, the narwhal is one of the strangest looking. It's a whale which has a large protruding tusk coming out of its head; that's how it got its nickname, the unicorn of the sea. They live in the Arctic Ocean off the coast of Canada, Russia and East Greenland. However, experts say some populations of narwhal could be extinct by 2025, and it's all because of noise pollution.

Narwhals rely on echolocation, which they use to find food and navigate their surroundings. The animal produces a sound wave which bounces off an object. They pick this reflected sound up through their lower jaw, and information on features like size and speed passes to their ears.

However, increase in human marine activity, as well as climate change, has resulted in the Arctic Ocean becoming noisier, which means it's more difficult for narwhals to rely on sound. Susanna Blackwell, who studies the effects of underwater noise on marine animals, told the BBC that there is noisier activity in the Arctic Ocean than ever because, as sea ice melts, new navigation routes are opening. And while icebergs breaking and creaking have been part of the ocean soundscape for hundreds of years, man-made noise is much harder for animals to adapt to, particularly as these changes are so sudden.

Research published in Science Advances in 2023 recorded the reactions of narwhals to the simulated noises of oil expeditions made by a patrol vessel. The scientists tagged and tracked the creatures and found that, on hearing these sounds, they ended deep dives and stopped clicking, the echolocation signal they use for finding food underwater. This is the same reaction narwhals have to orcas, who hunt them, meaning human-made noise could trigger the creature's 'threat button'.

So, what can we do? Charlotte Findlay, a postdoctoral fellow at Aarhus University, says "noise is actually quite easy to solve. We need to either turn it off or turn it down."

词汇表

narwhal 一角鲸
protruding 突出的，鼓出来的
tusk （动物的）长牙
unicorn of the sea 海洋独角兽
extinct 灭绝的
echolocation （动物的）回声定位
bounce off 从…反弹
lower jaw 下颌骨
marine activity 海洋活动
marine animals 海洋动物
navigation route 航线
soundscape 声景
adapt to 适应
tag 标记，给动物植入定位芯片
track 跟踪
deep dive 深潜
click （鲸鱼等动物）发出短而尖的声音
orca 虎鲸
hunt 捕猎

测验与练习

1. 阅读课文并回答问题。

1. Why is the narwhal strange looking?

2. How do narwhals navigate their surroundings?

3. Why is the Arctic Ocean noisier than ever, according to Susanna Blackwell?

4. How did scientists know the reactions of narwhals to simulated noises?

5. True or false? The narwhal's dived deeper when they heard the simulated noises.

2. 选择意思恰当的单词或词组来完成下列句子。

1. A whale is a type of ________.

narwhal marine animal orca unicorn

2. The orchestra aims to create an underwater ________ in their performance.

tusk soundscape route echolocation

3. Hospitals must ________ to advances in modern medicine.

tag track hunt adapt

4. There's an echo in this tunnel. The sound literally ________ the walls!

clicks bounces off notes simulates

5. Natalie wants to study ________ biology at university.

protruding marine strange man-made

答案

1. 阅读课文并回答问题。

1. Why is the narwhal strange looking?

Because it has a large, protruding tusk coming out of its head.

2. How do narwhals navigate their surroundings?

They rely on echolocation to navigate their surroundings.

3. Why is the Arctic Ocean noisier than ever, according to Susanna Blackwell?

Because, as sea ice melts, new navigation routes are opening.

4. How did scientists know the reactions of narwhals to simulated noises?

The scientists tagged and tracked the creatures.

5. True or false? The narwhal's dived deeper when they heard the simulated noises.

False. On hearing these sounds, they ended deep dives.

2. 选择意思恰当的单词或词组来完成下列句子。

1. A whale is a type of marine animal.

2. The orchestra aims to create an underwater soundscape in their performance.

3. Hospitals must adapt to advances in modern medicine.

4. There's an echo in this tunnel. The sound literally bounces off the walls!

5. Natalie wants to study marine biology at university.