There have been numerous wake-up calls about the effects of climate change on sea life. As ocean waters heat up, they are making coral lose color. Growing levels of carbon dioxide are making seawater more acidic. Now climate change is starting to affect fish's sense of smell, a phenomenon that will worsen in the coming years if global warming continues growing.
A sense of smell is what the fish can't do without. They use it to find food, detect upcoming danger, escape from predators (捕食者)find safe environments, and even recognize one another. "Future levels of carbon dioxide can have large negative effects on the sense of smell of fish, which can affect fish population numbers and the entire ecosystem, ”said an ocean life expert. "This can be prevented, but we must reduce carbon emissions now before it's too late.”
Experts believe that about half of carbon dioxide emissions produced by human activities, such as the burning of fossil fuels--have over time ended up in the oceans, lowering the pH of seawater, and making it more acidic.
Researchers found that sea bass (鲈鱼)exposed to the more acidic conditions swam less and were less likely to react when encountering the smell of a predator. Also, they were more likely to "freeze", a sign of anxiety, according to the study. They found the longer the fish were in high CO2,the worse they got along. The researchers also measured the ability of the fish to detect certain odors (气味)in different levels of acidity (酸度)。 The study showed that their ability to detect and respond to some odors connected with food and threatening situations was more strongly affected than other odors.
The research is important because 20 percent of the protein consumed by 3 million people comes from seafood, and about 50 percent of this comes from fish caught from the wild. “Therefore, increases in carbon dioxide in the ocean have the potential to affect all fish species, including those that many people rely on food and livelihood, "the ocean life expert warned.
12. What do we know from the first paragraph?
A.Global warming will continue in the coming years. |
B.Global warming is starting to affect fish's sense of smell. |
C.The temperature of seawater is rising to a dangerous level. |
D.Few people are worried about the impact of climate change. |
13. Why does the author attach great importance to the sense of smell of fish?
A.It can affect the survival of fish. |
B.Fish can stay safe with their sense of smell. |
C.Fish rely on their sense of smell to find food. |
D.Fish can find each other by their sharp noses. |
14. Why does the author mention human activities in the text?
A.He wants to blame human beings for global warming. |
B.He wants to criticize human beings for overuse of fossil fuels. |
C.He concludes that human activities can destroy the sense of smell of fish. |
D.He concludes that human activities can improve the ecosystem of the ocean. |
15. What is the author's attitude toward the future of fish industry?
A.Satisfied. | B.Enthusiastic. | C.Disappointed. | D.Concerned. |