For uncounted generations, trillions of coral polyps (珊瑚虫) have lived and died, leaving behind a material called limestone. Throughout History, limestone was used to construct the Great Pyramid of Egypt, as well as many churches and castles.   【小题1】. We can call them reefs (礁体). They can be even larger in scale than the most impressive buildings and structures made by humans.

【小题2】

Indeed, a living coral reef is remarkable, a “city beneath the sea” filled with a rich variety of life. Most coral reefs can be found in warm, shallow oceans. They occupy just a small part of the ocean floor, but host 25 percent of all ocean life. Each reef is full of colorful fish as well as coral that forms wonderful patterns. In addition to their beauty, the reefs are an important food source for fish, and for. humans.

Threats to coral reefs

【小题3】. For example, reefs can be damaged when the coral is taken for use in building materials or jewelry-making. Illegal fishing methods also harm reefs. These methods can help fishermen get a good catch, but their negative effects on the reefs are significant. Blast fishing involves setting off bombs in the water to kill as many fish as possible. 【小题4】 In addition, global warming has caused many reefs to become sick. A 2018 UN Report predicted that up to 99 percent of the world’s coral reefs may decline if global warming continues.   

Reasons for hope

These threats to coral reefs are very serious, but there is reason to hope that they will survive. If we take steps toward coral reef conservation, it is likely that these tiny creatures — which survived natural threats for millions of years — will be able to rebuild. As conservationist Robert Richmond says, “【小题5】. ”