Trawling (用拖网捕鱼) the seabed for fish is an environmental disaster; it wrecks

游客2024-01-31  18

问题    Trawling (用拖网捕鱼) the seabed for fish is an environmental disaster; it wrecks ecosystems, destroys fish stocks and leaves behind a marine desert. Right? Environment campaigners say so. But there is growing evidence that the effect is sometimes very different, with trawling increasing fish stocks from the North Sea to the California coast. A new modeling study may for the first time have demonstrated why.
   Trawlers attach large nets to a metal beam dragged across the seabed to catch bottom-dwelling fish. Greenpeace compares it to "driving a huge bulldozer through a forest", leaving a flat, featureless desert on the seabed. Trawling clearly does remove fish, such as large crustaceans and shellfish, says Daniel van Denderen of the Wageningen Institute for Marine Resources and Ecosystem Studies in the Netherlands. But this is a lucky break for softer, smaller species lurking in the sandy seabed, such as worms. They survive and, with fewer rivals, flourish.
And if, as is often the case, these smaller critters are the main food for fish, then the overall effect is to nurture more marine life. Imants Priede, director of Oceanlab at the University of Aberdeen, UK, says there is growing evidence that—while far from universal—the phenomenon is real. "On continental shelves such as the southern North Sea, where shifting sands and gravels are stirred up by strong tidal currents, even trawling more than once a year may be beneficial for some fish stocks," he says.
   In fact, studies going back 20 years have linked persistent trawling with increased fish stocks. The cause of this counter-intuitive finding has remained uncertain. Some have suggested that trawling stirs up the seabed, throwing potential food into the water column—rather like ploughing a field. Others think that discards from fish nets add to the food available on the sea floor. But van Denderen is the first to show how trawling can stimulate fisheries simply by drifting from ecosystems. "The findings are very important," says Priede. [br] Why does Greenpeace compare trawling to "driving a huge bulldozer through a forest"?

选项 A、Because trawling will make seabed become a desert.
B、Because trawling will make the forest become a flat and featureless area.
C、Because trawling is a huge bulldozer, which will destroy the forest.
D、Because trawling catches bottom-dwelling fish.

答案 A

解析 根据题干可以将该句定位至文章第二段。第二段第二句说Greenpeace compares it to“driving a huge bulldozer through a forest”,leaving a flat,featureless desert on the seabed。Greenpeace之所以把trawling比作“开着庞大的推土机穿过森林”是因为推土机破坏了森林的植被,而trawling让海床变成了海漠。因此答案为A选项。
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