一角鯨是一種頭上長有長牙的海洋哺乳動物。專傢表示，隨著氣候變暖，海冰融化，船舶航線增多，海洋噪聲增加，到2025年，一角鯨有可能會因海洋噪音污染而滅絕。本期 “隨身英語” 介紹這種被人稱作 “海洋獨角獸” 的動物所面臨的生存威脅。
詞匯：marine animals 海洋動物
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 AYYBLOG 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.”
詞匯表
narwhal 一角鯨
protruding 突出的，鼓出來的
tusk （動物的）長牙
unicorn of the sea 海洋獨角獸
extinct 滅絕的
echolocation （動物的）回聲定位
bounce off 從…反彈
lower jaw 下頜骨
marine activity 海洋活動
marine animals 海洋動物
navigation route 航線
soundscape 聲景
adapt to 適應
tag 標記，給動物植入定位芯片
track 跟蹤
deep dive 深潛
click （鯨魚等動物）發出短而尖的聲音
orca 虎鯨
hunt 捕獵
測驗與練習
1. 閱讀課文並回答問題。
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. 選擇意思恰當的單詞或詞組來完成下列句子。
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. 閱讀課文並回答問題。
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. 選擇意思恰當的單詞或詞組來完成下列句子。
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.
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