As the Earth warms from the increase of carbon dioxide in its atmosphere, the oceans that cover 70 percent of its surface are warming too. This warming will likely benefit some sea species at the expense of others.
A study in the May 20 issue of the journal Nature confirmed that there has been a warming trend in the world’s oceans since 1993, as the waters have absorbed much of the extra energy in the planet’s atmosphere.
The warming that has already occurred, and is expected to continue in the coming decades, will likely spell bad news for many ocean species, such as corals and species that live in the cold waters of the planet’s poles. But some creatures beneath the ocean surface might actually have an advantage in the newly wanned waters.
A 2008 study, for example, said that a warming of just a few degrees Fahrenheit in Antarctic waters could make them suitable to sharks,which haven’t lived in the area for about 40 million years. It’s easier for sharks to keep their high metabolism in warmer waters. If sharks do move into the area,they could cause damage to the existing ecosystems of the oceans around Antarctica.
A study of starfish found these typical ocean creatures grew faster in water at warmer temperatures and higher carbon dioxide levels ( another result of all the extra greenhouse gas in the atmosphere) than at normal conditions—which is bad news for the shellfishes they live on.
Work by Jeremy Jackson, a professor at Scripps Institution of Oceanography at the University of California at San Diego, suggests that ocean warming—along with other threats such as overfishing and habitat destruction—could change once complex ocean ecosystems into ones that favor simpler species, such as microbes, toxic algal blooms and jellyfishes.
1.How is Paragraph 3 developed?
A.By giving examples.
B.By analyzing causes.
C.By making comparisons.
D.By making classifications.
2.What can we know about sharks from the fourth paragraph?
A.They are native to Antarctic waters.
B.They do harm to the whole ecosystem.
C.They’re adaptable to warmer water conditions.
D.They threaten simpler species in Antarctic waters.
3.What will ocean warming likely bring about?
A.Promoting the growth of starfish.
B.An ecosystem of smaller creatures.
C.Different food sources for sea creatures.
D.Damaging living places of deep-sea species.
4.What is the purpose of the passage?
A.To explain why ocean warming benefit some species.
B.To introduce how creatures survive in warmer oceans.
C.To clarify some misunderstandings about ocean warming.
D.To show which creatures will benefit from warmer oceans.
