When prehistoric man arrived in new
parts of the world, something strange happened to the large animals: they
suddenly became extinct. Smaller species survived. The large, slow-growing
animals were easy game, and were quickly hunted to extinction. Now something
similar could be happening in the oceans. That the seas are being overfished has been known for years. What researchers such as Ransom Myers and Boris Worm have shown is just how fast things are changing. They have looked at half a century of data from fisheries around the world. Their methods do not attempt to estimate the actual biomass (the amount of living biological matter) of fish species in particular parts of the ocean, but rather changes in that biomass over time. According to their latest paper published in Nature, the biomass of large predators (animals that kill and eat other anima A. (A) large animals were vulnerable to the changing environment B. (B) small species survived as large animals disappeared C. (C) large sea animals may face the same threat today D. (D) slow-growing fish outlive fast-growing ones [单项选择]When prehistoric man arrived in new parts of the world, something strange happened to the large animals. They suddenly became extinct. Smaller species survived. The large, slow growing animals were easy game, and were quickly hunted to extinction. Now something similar could be happening in the oceans.
That the seas are being overfished has been known for years. What researchers such as Ransom Myers and Boris Worm have shown is just how fast things are changing. They have looked at half a century of data from fisheries around the world. Their methods do not attempt to estimate the actual biomass (the amount of living biological matter) of fish species in particular parts of the ocean, but rather changes in that biomass over time. According to their latest paper published in Nature, the biomass of large predators (animals that kill and eat other animals) in a new fishery is reduced on average by 80% within 15 years of the start of exploitation. In some long fished areas, it has h A. large animals were vulnerable to the changing environment B. small species survived as large animals disappeared C. large sea animals may face the same threat today D. slow growing fish outlive fast growing ones [填空题]When a man has a biological need is always automatically satisfied.
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