题型:阅读理解 题类:常考题 难易度:普通
河南省中原名校2020届高三上学期英语第四次质量考评试卷
Scientists Diego Kersting and Cristina Linares have found that some coral species are able to recover from harmful warming events through a unique survival strategy (策略)—known as "rejuvenescence" (新生)—among corals in the Mediterranean Sea. The findings represent some rare good news for corals around the world, which are facing numerous severe threats—most notably, climate change.
"The main threats are climate change, overfishing, pollution and coastal urbanization," Kersting said. "But currently, climate change is probably the one causing the most coral cover declines. Warming stresses corals up to a point that may cause death. Some corals bleach (白化) before dying. Other corals do not bleach but die directly." He went on, "Our findings are significant because this survival strategy was only known from fossil corals that existed hundreds of millions of years ago. It is the first time that it has been found in a living coral. Thanks to our findings, we know now that some corals are able to recover, but unfortunately this is not enough in the current climate change context."
For their research, Kersting and Linares monitored 243 colonies of the endangered reef-building coral Cladocoracaespitosa in Spain's Columbretes Islands Marine Reserve over 16 years, starting in 2002. The monitoring revealed that Cladocoracaespitosa in the Mediterranean uses rejuvenescence to cope with warming events. This process involves the polyps — or the individual coral animals in a colony—shrinking inward and abandoning their skeletons (骨骼) during warm periods, before rejuvenating at a later point. "What happens is that some polyps in a coral colony—sometimes just one— reduces completely its dimensions and partially retreats from its skeleton," Kersting said. "Once the stressful event is over, the shrunken or rejuvenated polyp recovers its size and builds up a new skeleton. Eventually, it begins to reproduce itself through budding and begins to cover the dead colony surfaces."
He continued, "The results were very surprising because I started to observe colonies that were dead years ago, that were showing living parts many years after their death."
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