英语听力文摘 外来物种入侵
Ocean’s Most Wanted
伴随着人们的经济活动和国际交往，一些物种由原生存地借助于人为作用或其他途径移居到另一个新的生存环境并在新的栖息地繁殖并建立稳定种群，这些物种被称为外来物种。我国是世界上海洋生物多样性最丰富的国家之一，被国际保护组织誉为“生物多样性大国”和“生物多样性全球热点地区”。但随着我国海洋运输事业的发展、国际贸易的日趋频繁、海水养殖品种的传播和移殖，我国海洋外来物种数量越来越多，对我国的海洋生物多样性和海洋生态系统安全带来了严重影响。以养殖生物为例，鲍、牡蛎、扇贝、对虾、鱼类、藻类等大量从国外引入亲体，甚至新物种，在养殖过程中由于各种方式导致养殖对象进入自然海域，不仅与当地土著生物争夺生存空间、饵料，争夺生态位，并且传播疾病、与土著生物杂交导致遗传污染，降低土著生物的生存能力，导致土著生物自然群体降低，甚至濒于灭绝。
They might seem innocent and lovely in your (1)aquarium, but released into the wild, your plants and fish can knock aquatic ecosystems right out of balance.
Today’s invasive species: the (2)water hyacinth.
Native to the Amazon basin, but considered an ornamental aquarium plant, the water hyacinth was introduced to Florida in 1884. By the mid-1950s, water hyacinths were clogging Florida’s water ways and interfering with navigation, not to mention displacing the native species. Clean up took millions of dollars, and they’re still spreading on every continent except Antarctica.
Guess how many of the species on the International Union for the Conservation of Nature’s list of the one-hundred worst (3)invasive species are the result of aquarium and ornamental releases?
How many?
A full third! You see, when it comes to aquarium animals and plants, we’re dealing with mature adults, and particularly hardy ones at that, since the weaker ones don’t survive transport. So whenever they’re released into the environment, either intentionally or accidentally, they’re better able to establish themselves.
Despite all this, until recently researchers have largely ignored the role of pet fish and aquarium plants when studying the spread of exotic and invasive species. Finally, it’s time for some guidelines(指导方针), especially ones that encourage the trade of less invasive and aggressive species, or the substitution of native and/or safer species that people could grow instead.
译文：
在你的水族箱里它们或许看起来很天真，很可爱。但是一旦被放生到野外，你的植物和鱼就会打破水生生态系统的平衡。
今天的入侵物种是：水葫芦。
水葫芦原产于亚马逊河流域，但作为一种观赏性水生植物，在1884年被引入佛罗里达州。到20世纪中期，水葫芦就造成了佛罗里达州水路的堵塞，干扰航运，更何况还取代了本地物种。尽管清理花费了数百万美元，但是它们仍然在除南极洲以外的各大洲蔓延。
你猜猜在国际自然保护联盟的最严重的100个入侵物种名单里，有多少是因为水族箱和观赏性放生造成的?
有多少呢?
整整三分之一!你知道的在选取水族馆动植物品种时，我们一般选用已长大成熟的动植物，尤其是易养活的那类，因为其他那些相对脆弱的动植物在运输的路途上无法存活下来。因此不论他们何时被放生到外界，故意的或是无意的，它们都能够很好的适应生存。
尽管如此，直到最近研究者们在研究外来入侵物种时都很大地忽略了宠物鱼和水生植物所扮演的角色。最后，是时候该制定一些指导方针了，特别是针对减少入侵和侵略物种交易的规定，或者取而代之种植一些本地的和更安全的物种。
Notes:
(1)aquarium [?'kwε?ri?m] n.水族馆;养鱼池;玻璃缸
Visit an aquarium shop and watch how fish swim.
参观一间水族店，观察鱼类如何游泳。
(2)water hyacinth 水葫芦;凤眼兰;凤眼蓝
(3)invasive [in'veisiv] adj.侵略性的;攻击性的
Now, what type of invasive lobular carcinoma is it?
那么，是什么亚型的浸润性小叶癌呢?
