英语听力精选进阶版 13963

Shrinking fish

Summary

2 October 2012

Fish species around the world are expected to shrink in size by up to 24%, according to a new scientific analysis. Researchers say that rising temperatures could decrease oxygen levels in the sea and significantly reduce fish body weight.

Reporter:

Matt McGrath

Report

Although projections¹ of global temperature rises show relatively² small changes at the bottom of the oceans, the resulting impacts on fish body size are "unexpectedly large", according to this research. As ocean temperatures increase, so do the body temperatures and metabolic³ rates of the fish. This means they use more oxygen to stay alive and, according to the researchers, they have less available for growth. 

They've calculated that up to 2050, fish will shrink in size by between 14 and 24 percent, with the Indian and Atlantic Oceans worst affected⁴. The warming waters are also likely to drive fish more towards the poles, leading to smaller species living in areas like the North Sea. 

According to the scientists, their models may underestimate the potential impacts. When they looked at case studies involving North Atlantic cod⁵ and haddock, they found that recorded data on these fish showed greater decreases in actual body size than the models predicted.

1 projections   

预测( projection的名词复数 )； 投影； 投掷； 突起物

参考例句：

• Their sales projections are a total thumbsuck. 他们的销售量预测纯属估计。
• The council has revised its projections of funding requirements upwards. 地方议会调高了对资金需求的预测。

2 relatively   

adv.比较...地，相对地

参考例句：

• The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
• The operation was relatively painless.手术相对来说不痛。

3 metabolic   

adj.新陈代谢的

参考例句：

• Impressive metabolic alternations have been undergone during embryogenesis.在胚胎发生期间经历了深刻的代谢变化。
• A number of intoxicants are associated with metabolic acidosis.许多毒性物质可引起代谢性酸中毒。

4 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

5 cod   

n.鳕鱼；v.愚弄；哄骗

参考例句：

• They salt down cod for winter use.他们腌鳕鱼留着冬天吃。
• Cod are found in the North Atlantic and the North Sea.北大西洋和北海有鳕鱼。