Thirty years ago, if you looked down from a plane at the east coast of Australia, you would be greeted by the breathtaking beauty of the Great Barrier Reef (大堡礁), the world's largest coral reef. It stretched for over 2,600 kilometres in the blue sea, containing countless corals and small islands. It was listed as a UNESCO World Heritage Site in 1981.
However, this natural wonder of the world is being taken away from us. Coral cover in the Great Barrier Reef has dropped by more than half over the last 28 years, The Guardian reported. “If the trend continues, coral cover could halve again by 2022,” said Peter Doherty, researcher at the Australian Institute of Marine Science (AIMS). So unless we start acting now, there won’t be any “heritage” left in the future.
Coral reefs are an important part of the ocean’s ecosystem. They are a source of food, and act as protection for young fish. But in the past three decades they have been under threat around the world mainly from increased storms, a growing number of crownofthorns starfish and coral bleaching (褪色).
Storm damage caused nearly half of the coral losses. In the past seven years, the reef has been affected by six major storms, each leaving a trail (痕迹) of destruction.
The crownofthorns starfish is also causing problems. Scientists believe that runoffs (地表径流) containing a large amount of fertilizers have caused the population boost of this coraleating animal. Outbreaks of crownofthorns starfish usually start two or three years after major floods in northern rivers.
Coral bleaching accounts for about 10 per cent of coral damage. It is usually due to ocean acidification (酸化) and rising temperatures because sea water absorbs more carbon dioxide from the air. This disrupts the corals' ability to grow and build structures.
The good news is that corals can recover if given the chance. But this is slow. And the future of the ocean’s coral is largely in human hands.
“We can’t stop the storms…But we can achieve better water quality, and we can deal with the challenge of crownofthorns starfish,” says John Gunn, CEO of AIMS. “However, its future also lies with the global response to reducing carbon dioxide emissions (排放). ”
【小题1】What can we learn about the Great Barrier Reef from the article?A.As the world’s second largest coral reef, the Great Barrier Reef was listed as a UNESCO World Heritage Site. |
B.The Great Barrier Reef has lost more than half of its coral cover since 28 years ago. |
C.At the present rate of loss, the coral cover will reduce by another 30 per cent within a decade. |
D.Coral reefs are an important part of the ocean's ecosystem and can prevent ocean acidification. |
A.at risk | B.out of sight |
C.in demand | D.beyond recognition |
a. Improve water quality.
b. Reduce global carbon dioxide emissions.
c. Disrupt the coraleating starfish’s ability to build structures.
d. Control the population of the crownofthorns starfish.
e. Make ocean absorb more carbon dioxide from the air.
A.a, b, c | B.a, b, d |
C.a, c, e | D.b, d, e |