Today, we are building more islands than ever before. Why are islands built? One big reason is tourism (旅游业) . For example, the Pearl Island in Qatar, a fantastic man-made island with excellent five-star hotels, is popular with tourists around the world. Another reason is to provide more land for people in crowded cities.____For example, in 2021, Denmark planned to build an island for about 600 wind turbines(风力涡轮机) that could turn wind power into electricity.
To build islands, workers take tons of sand and stones from the bottom of the sea,making the water become dirty. If it gets too hazy, sunlight can't pass through. It's bad for coral reefs(珊瑚礁) and sea plants that need plenty of sunlight to live. If they are dying, other sea life that depends on them for food will be in danger.
Engineers have created some ways to reduce the bad effects. For example, they use a special net(网) to stop sand from spreading through the sea while working. They also create a"living seawall(海堤) "which provides friendly living conditions for sea life.
Actually, whether or not to build islands is not a simple question. Perhaps its bright sides are much more important to humans. It also calls for more attention to be paid to the environment in the process(过程). Let's take action in a smart way!