第19回 の解答
テーマ：海洋酸性化 正解は緑、解説・和訳・スクリプト・模範解答つき
語彙・熟語（大問1形式）
目安 2分30秒空所に入れるのに最も適切なものを1つ選びなさい。
訳：海水の酸性度が高まるにつれて、海水がカキやハマグリの殻を腐食し始め、これらの生物が生き延びるのを難しくする。
訳：科学者たちは、二酸化炭素濃度が上昇し続ければ、サンゴ礁への損傷の一部が不可逆的になり、サンゴ礁が二度と元の状態に戻れなくなるかもしれないと懸念している。
訳：多くのサンゴ礁は今や危うい状態にあり、科学者たちは水温がさらにわずかに上昇するだけでも回復不能な状態に追いやられる可能性があると警告している。
訳：貝の漁獲量が減っている問題はそのうち収まるだろうと期待する漁師もいたが、科学者たちは海洋酸性化は長期的な傾向だと警告した。
訳：会議で、その教授は海洋酸性化の化学について1時間近くも長々と話し、多くの聴衆は彼の説明についていくのに苦労した。
長文読解（大問3形式）
目安 4分30秒The Other Carbon Dioxide Problem
When people think about the effects of carbon dioxide, they usually focus on global warming. However, the ocean absorbs a substantial share, roughly a quarter, of the carbon dioxide released by human activities, and this has consequences of its own. When carbon dioxide dissolves in seawater, it forms carbonic acid, gradually lowering the water's pH. Since the Industrial Revolution, the surface ocean has become noticeably more acidic, and many scientists believe the change is unusually rapid by geological standards.
This change makes it harder for organisms such as corals, oysters, and some types of plankton to build their shells and skeletons, which are made of calcium carbonate. Because tiny shell-forming plankton are an important food source for fish, the effects could spread throughout the marine food chain. Laboratory experiments, however, show that responses vary widely between species. Some organisms appear able to adapt, at least partially, and certain plants, such as seagrasses, may even grow faster in water containing more carbon dioxide. This variation makes it difficult to predict exactly how entire ecosystems will change.
The consequences are already being felt in some places. Oyster farms on the west coast of the United States have experienced mass deaths of young oysters when unusually acidic water rose from the deep ocean. To protect their businesses, many now monitor the water's chemistry and pump seawater into their hatcheries only when conditions are favorable, or add chemicals to reduce its acidity. Such measures can help individual businesses, but they are impractical on the scale of the open ocean. Most scientists therefore agree that the only lasting solution is to reduce carbon dioxide emissions.
リスニング（Part2 文章形式）
目安 2分🎙 Can seaweed help fight ocean acidification? Researchers believe it might, at least on a local scale. Like plants on land, seaweed and seagrass absorb carbon dioxide from their surroundings as they grow. This process can reduce the acidity of nearby water, creating small areas where shellfish can build their shells more easily. Some oyster farmers are therefore growing kelp alongside their oysters. The kelp can also be harvested and sold as food or fertilizer, giving farmers an extra source of income. However, scientists caution that seaweed farming is not a solution to the global problem. The ocean is simply too vast, and the only way to stop acidification worldwide is to reduce carbon dioxide emissions.
スピーキング（面接No.4形式）
40秒Human activities are causing serious damage to the world's oceans.
Should people eat less seafood to protect the ocean environment?
💡 「完全にやめる」ではなく「減らす／選ぶ」と現実的な提案にすると説得力が増す。
模範解答
はい、そう思います。乱獲により多くの魚の個体数が減少しており、私たちが習慣を変えなければ姿を消す種もあるかもしれません。魚介類を食べる量を減らすか、持続可能な方法で獲られた魚を選べば、海の生態系に回復する時間を与えられます。これは将来の漁業を守ることにもつながります。
💡 「完全にやめる」ではなく「減らす／選ぶ」と現実的な提案にすると説得力が増す。