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  • Coral reefs are like the rainforests of the sea, and like those here on land, they're

  • being destroyed. But why should you care?

  • Howdy friends under the sea, Trace here for DNews. When you picture coral you probably

  • see it like THIS[a] right? But coral aren't just colorful rocks. Tiny living things live

  • in there. Those "rocks" are actually the skeletons of polyps, which look like this[b]. Polyps

  • constantly secrete calcium carbonate to build these protective skeletons. This is why people

  • say coral reefs are living, not because the calcium structures are alive, but because

  • the polyps live inside those structures -- like a turtle in a shell -- only popping out to

  • feed or occasionally fight with one another.

  • Coral are related to jellyfish, and sea anemones and are not mobile animals, instead they anchor

  • and live their whole lives in one place. Polyps can be as small as the head of a pin or as

  • large as a foot across (30 cm) and while some grow in groups, others are solitary. The varied

  • colors in their bodies comes from symbiotic algae that live inside of them. As they grow

  • and die, more coral grow on top of them, and over millions of years, coral pile together

  • to form giant coral reefs that create the basis for 25 percent of ALL ocean life, even

  • though they're only point-one percent of the area of the ocean -- again, rainforest of

  • the sea.

  • Coral appeared in the fossil record 400 million years ago. As the polyps grow through their

  • life cycle, the calcium carbonate they secrete will sometimes merge with the secretions of

  • other polyps around them, forming shapes. The polyps can form tables, pillars, spiral

  • wires, staghorns, and brain coral. They're all rigid structures with living polyps, but

  • they live in different places and require different conditions. These shapes are affected

  • by weather, currents and of course human and large animal activity. When coral like this

  • band together, they're called "reef building coral," and they form some of the most diverse

  • ecosystems on our planet.

  • If you're like me, you grew up hearing the reefs were important, but I was never sure

  • WHY. After researching, I get it. I could list all the animals living in a coral reef,

  • but to be honest, this DNews episode would never end. There are literally millions of

  • species that subsist in, on and around coral reefs. They've been around for millions of

  • years, so it's safe to say there are likely fish, crustaceans and algae that evolved to

  • live on reefs and nowhere else, just like insects, mammals and birds in the Amazon.

  • It's mind-boggling.

  • Thats not all they do. Coral also control how much carbon dioxide is in the ocean. They

  • take the carbon dioxide out of the water, and use it to build their calcium carbonate

  • skeletons. Without coral, the amount of CO2 in the water would affect the whole planet,

  • but luckily, they trap that in stone for us all.

  • And if housing species, looking awesome, and saving the planet wasn't enough... Coral reefs

  • alter how the ocean affects the shore. Because they build up over millions of years, and

  • can survive live in warm shallow water as well as colder deeper water, reefs can span

  • massive areas and undulate like mountain ranges. They build themselves to withstand typhoons,

  • hurricanes and other tropical storms, and therefore buffer the shore against waves,

  • storms, and floods! These tiny animals evolved long before we did, and their existence in

  • areas like Australia and Florida can prevent loss of life, property damage, and erosion

  • by tempering the rushing ocean.

  • Today, coral are in trouble. Because coral are so sensitive to water temperature, global

  • warming/climate change, ocean acidification, ecotourism and commercial overfishing are

  • beginning to kill off these tiny animals. In fact, when the animal is stressed, they

  • release their symbiotic colorful algae into the water, turn white and die. Which is why

  • it's important to think of coral not as pretty rocks but as living things like a dog or an

  • elephant.

  • A new 42 year study of coral has found we've only got about a sixth of the coral left on

  • our planet -- with the Caribbean losing 50-percent of their coral since 1970. But all hope is

  • not lost, the parrotfish might be a coral savior. Where parrotfish live, coral are thriving,

  • so new sanctions on the protection of parrotfish are being considered. With a bit of effort

  • we can help these little animals continue another 400 million years, and it helps to

  • get to know them a bit better, right?

  • Do you know more about coral now? Want to know about something else?

  • Tell us in the comments and subscribe. Also, come to Facebook, Twitter and GooglePlus to

  • say hello. We love you guys, thanks for watching.

Coral reefs are like the rainforests of the sea, and like those here on land, they're

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珊瑚礁是什麼,有什麼作用? (What Are Coral Reefs And What's Their Purpose?)

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    Jack 發佈於 2021 年 01 月 14 日
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