The Mediterranean Sea is home to some 17,000 native species. But it's also home to a growing number of non-native species: 756 at last count. 756 may not sound like a lot, compared to 17,000.

地中海是大约17000种本土物种的家园。同时它也是越来越多的非本土物种的家园：据最新统计当地非本土物种为756种。相比17000种本土物种，这似乎听起来并不是很多。

"But this is not arithmetic." Bella Galil, a naturalist at Israel National Center for Biodiversity Studies in Tel Aviv. "Those invasive species have a large population, and they rend apart the native food web. They disturb an already stressed community."

“但这不是算术问题。”来自特拉维夫以色列国家生物多样性研究中心的博物学家贝拉·加利尔说道。“这些入侵物种种群非常大，它们会分裂本地的食物链。它们还扰乱了本就已经很紧张的社区。”

The invaders she's talking about are central casting for an underwater horror movie. Take the nomadic jellyfish, in huge swarms 60 miles long, which sent hundreds of people to Turkish hospitals a few summers back. Or a type of pufferfish, extremely poisonous, that occasionally gets fished out, and lands at fish markets by mistake.

她所说的入侵者可以说是一部水下恐怖片的演员阵容了。以游动型的水母为例，其巨大的种群阵容可达60英里长，几个夏天以来已有数百人因被它们蛰伤而去土耳其医院就医。又或者以一种体内含有剧毒的河豚鱼为例，它们偶尔会被捕鱼的人捞出，然后不小心被放到鱼市上售卖。

Galil says these bad guys, and many others, have invaded the Mediterranean through the ever-widening Suez Canal. As the canal grows, so do the number of non-native species. And it's a dilemma that's not easily addressed. "It's a Humpty-Dumpty sort of problem. Once it's broke it's broke. We cannot re-engineer it. It's too complex for us." Galil and her team outline the scope of the problem in the journal Management of Biological Invasions.

加利尔表示，这些“坏家伙”连同其它许多物种，通过日益扩大的苏伊士运河入侵进地中海。随着运河的扩大，非本土物种的数量也在增加。而这又是一个难以解决的难题。“这是一个一旦产生便无法修复的问题。一旦被打破，便只能如此。我们不能对其进行重新设计。这对我们来说太复杂了。”加利尔和她的团队在《生物入侵管理》杂志中概述了这个问题的范围。

Installing locks or salinity barriers could help block future invasions, she says—those methods have worked in other canals. But that's an engineering and governance issue. "As biologists we've raised our voices. The community is aware of it. The problem is to go beyond this. And to go beyond this we need to go into the regional bureaucracy and the industry." It'll undoubtedly cost money, too. One motivating factor for taking action: Mediterranean beaches are big business. And swarms of jellyfish can quickly drive away the customers.

她表示，安装水闸或盐度屏障或许有助于阻止将来发生物种入侵。这些方法已经在其他运河中起到了作用。但这是一个工程和治理问题。“作为生物学家我们已经尽力发出了呼声。社会上也意识到了这一问题。但问题是这还远远不够，为了真正达成应有的效果，我们还需进入到该地区的官僚机构和工业产业中。”毫无疑问，这需要资金。能够激励地方采取行动的一个因素是：地中海海滩经济规模很大。而成群的水母则会很快让游客们望而却步。