海獺是一種生活在北美西海岸從加州到阿拉斯加沿線的小型海洋哺乳動物。託福TPO10綜合寫作就海獺數量減少的原因進行了分析。下面是小編整理的託福TPO10綜合寫作參考範文，希望能幫到大家!
The lecturer and the reading passage suggest two competing theories, the predation theory vs. the pollution theory, to explain why the sea otter population is in rapid decline.
The professor reasons that the absence of dead sea otters washed up the coast suggests that their decline is not caused by sea pollution but rather by sea predators who consume their bodies after Killing them. In contrast, the reading passage attributes the death of sea otters to pollution, citing evidence of increased sources of ocean contaminants which lead to greater vulnerability to infections.
Furthermore, the lecturer argues that orcas are likely factors in the disappearance of sea otters, because the scarcity of whales, their usual prey, has left them with no other choice but to start hunting smaller mammals like the otters for food. The reading passage, on the other hand, Rules out this theory based on the orca's preying habit, and instead approves of the pollution theory as the only explanation for the decline op both large and small sea mammals across the entire ecosystem.
Finally, according to the lecturer, the uneven pattern of sea otter decline corresponds to the distribution of the orcas. she argues that the pact that their population has declined most rapidly where orcas are most prevalent further validates the predation theory. However, the reading passage argues that changeable environmental factors, which lead to different concentrations of pollutants, better explains the varying pattern of sea otter decline.
託福TPO10綜合寫作閱讀材料：The sea otter is a small mammal that lives in waters along the western coast of North America from California to Alaska. When some sea otter populations off the Alaskan coast started rapidly declining a few years ago, it caused much concern because sea otters play an important ecological role in the coastal ecosystem. Experts started investigating the cause of the decline and quickly realized that there were two possible explanations: environmental pollution or attacks by predators. Initially, the pollution hypothesis seemed the more likely of the two.
海獺是一種生活在北美西海岸從加州到阿拉斯加沿線的小型海洋哺乳動物。幾年前，阿拉斯加海岸的海獺數量急劇減少。由於海獺對於維持海岸沿線生態平衡有非常重要的作用，所以其數量下降引起了廣泛的關注。專家開始研究海獺數量下降的原因，並且很快發現了兩個可能的原因，分別是環境汙染和天敵捕食。最初，環境汙染說看起來更為可信。
The first reason why pollution seemed the more likely cause was that there were known sources of it along the Alaskan coast, such as oil rings and other sources of industrial chemical pollution. Water samples from the area revealed increased levels of chemicals that could decrease the otters’ resistance to life-threatening infections and thus could indirectly cause their deaths.
為什麼汙染說更為可信呢?這是因為阿拉斯加海岸確實有汙染源，比如石油帶或者其他的工業汙染物。該地的水樣顯示水中化學物的含量增加，其數量可以導致海獺對於對於一些致命感染喪失抵抗力，進而間接導致數量下降。
Second, other sea mammals such as seals and sea lions along the Alaskan coast were also declining; indicating that whatever had endangered the otters was affecting other sea mammals as well. This fact again pointed to environmental pollution, since it usually affect the entire ecosystem rather than a single species. Only widely occurring predators, such as the orca (a large predatory whale), could have the same effect, but orcas prefer to hunt much larger prey, such as other whales.
第二，在阿拉斯加海域，包括海豹和海獅在內的其他海洋哺乳動物的數量也有所下降。這表明造成海獺數量下降的原因也對其他海洋哺乳動物造成了影響。原因再次指向了環境汙染，這是因為環境汙染問題常常不是僅僅影響某個特定物種，而是影響整個生態系統。除此之外，只有像逆戟鯨(一種大型肉食鯨)那種食性廣泛的動物才能通過捕食呈現相同的效果。但是，逆戟鯨更喜歡捕食像鯨類這種的大型獵物。
Third, scientists believed that the pollution hypothesis could also explain the uneven pattern of otter decline: at some Alaskan locations the otter populations declined greatly, while at others they remained stable. Some experts explained these observations by suggesting that ocean currents or other environmental factors may have created uneven concentrations of pollutants along the coast.
第三，科學家認為汙染說同時可以解釋海獺數量變化的不均衡性。所謂不均衡性是指在阿拉斯加某些區域海獺數量下降明顯，而在其他地方海獺的數量保持未定。一些專家指出這樣的觀察結果表明洋流和其他環境因素導致了海岸線上汙染物的不均衡聚集。
託福TPO10綜合寫作聽力材料：Well, ongoing investigations have revealed that predation is the most likely cause of sea otter decline after all.
目前的研究表明天敵捕食是最可能導致海獺數量減少的原因。
First, the pollution theory is weakened by the fact that no one can really find any Dead Sea otters washing off on Alaskan beaches. That’s not what you would expect if infections caused by pollution started killing a lot of otters. On the other hand, the fact that it’s so hard to find dead otters is consistent with the predator hypothesis. If an otter is killed by a predator, it’s eaten immediately so it can’t wash up on shore.
首先，由於沒有人發現有海獺屍體被衝上阿拉斯加海灘，所以汙染理論捕食那麼站得住腳的。如果汙染造成的疾病感染導致了海獺數量的劇減，那麼情況不該如此。而且，很少發現海獺屍體也恰恰說明了天敵捕食假說。捕食者殺死了海獺後，會很快地吃掉它，那麼我們也就不會再岸上發現海獺屍體了。
Second, although orcas may prefer to hunt whales, whales have essentially disappeared from the area because of human hunters. That means that orcas have had to change their diet to survive and since only smaller sea mammals are now available, orcas have probably started hunting those. So, it probably is the orcas that are causing the decline of all the smaller sea mammals mentioned in the passage - the seals, the sea lions, and the sea otters.
第二，儘管逆戟鯨喜歡捕食鯨類，但是鯨類的數量卻由於人類的`捕獵活動而劇烈減少。這意味著逆戟鯨不得不為了生存而更改捕食習慣。目前來看只有一些小型海洋哺乳動物還可以捕捉，逆戟鯨很可能開始以它們為食了。所以，很可能是逆戟鯨的捕食導致了文中提到的諸如海豹、海獅和海獺等小型哺乳動物的數量減少。
And third, the uneven pattern of otter decline is better explained by the orca predation theory than by the pollution theory. What happens to otters seems to depend on whether the location where they live is accessible to orcas or not. In those locations that orcas can access easily, the number of sea otters has declined greatly. However, because orcas are so large, they can’t access shallow or rocky locations. And shallow and rocky locations are precisely the types of locations where sea otter populations have not declined.
第三，海獺數量變化的不均衡性恰好表明了逆戟鯨捕食理論比汙染理論更合理。海獺數量的增減取決於它們生存的地方逆戟鯨是不是可以進入。在那些逆戟鯨很容易進入的海域，海獺的數量急劇減少。然而，因為逆戟鯨個頭很大，所以他們不能進入那些過淺或者充滿岩石的海域。而那些過淺和充滿岩石的海域，恰恰是海獺數量保持穩定的地區。
