·科学·
B1

Giant Cuttlefish Numbers Drop 97% in Australia Breeding Event

オーストラリアの繁殖イベントで巨大コウイカの数が97%減少

#australia#marine life#cuttlefish#environment#ocean
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Every winter, thousands of giant cuttlefish gather along the coast of South Australia for the world's largest cuttlefish mating event. These colourful sea creatures attract divers from all over the world. But this year, scientists and divers noticed a shocking change: almost no cuttlefish arrived.

Official estimates show that only 1,811 cuttlefish came to mate this year. Last year, there were about 63,000. That is a massive 97 percent drop and the lowest number ever recorded. Even worse, divers found only about 440 eggs along the coast, where millions of eggs are usually laid under rocks. Because adult cuttlefish die after breeding, having so few eggs means the next generation could be in danger.

having [X] means [Y]= 〜であるということは、…を意味する・〜という結果につながる

Experts believe a toxic algae bloom along the coastline may be the main reason for the decline. Algae are tiny aquatic plants that can grow quickly when water gets warmer. Ocean warming and pollution have caused harmful algae to spread across South Australia's waters for more than 18 months. Cuttlefish and other ocean animals like octopus and squid are very sensitive to these toxins.

main reason for [noun]= 〜の主な原因・理由

Environmental groups are now asking the government to list the giant Australian cuttlefish as an endangered species. While government officials note that cuttlefish numbers naturally rise and fall over time, researchers say this record low is a serious warning sign for marine ecosystems. They hope the population will be able to recover in the coming years if ocean conditions improve.

rise and fall= (数値や状況が)増減する、変動する

学習ノート

表現パターン

パターン意味
having [X] means [Y]〜であるということは、…を意味する・〜という結果につながる
main reason for [noun]〜の主な原因・理由
rise and fall(数値や状況が)増減する、変動する

語彙

レベル意味
cuttlefishB1コウイカ
estimatesB1推定値、見積もり
marineB1海の、海洋の
declineB2減少、低下
endangeredB2絶滅の危機に瀕した

言語メモ

  • 南オーストラリア州のスペンサー湾は、求愛行動時に体色や模様を素早く変化させる巨大コウイカ(Sepia apama)の集団産卵地として世界的に有名です。
  • 有毒藻類の集団発生(赤潮現象)は水温上昇や環境汚染により加速し、水中酸素の欠乏や生物毒素の発生を引き起こして海洋生物に大きなダメージを与えます。

練習

読んだ内容を確認しましょう。

  1. Environmental groups are now asking the government to list the giant Australian cuttlefish as an   species.

  2. What do experts believe is the main cause of the sharp drop in cuttlefish numbers?

  3. In the sentence 'cuttlefish numbers naturally rise and fall over time', what does 'rise and fall' mean?

Source: BBC World