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Sharks have been top dog in the Pacific for millions of years. They control the numbers of other fish, and so play a vital role in keeping the underwater ecosystem healthy and diverse. In French Polynesia, grey reef sharks gather. While scalloped hammerheads patrol the Galapagos Islands, these are rare hot spots where sharks converge in large numbers. But divers claim this is just a fraction of the number of sharks they used to see. Many sharks are ocean migrants, travelling hundreds of miles in search of prey, like the oceanic whitetip. Amazingly, this may once have been the most abundant large animal on the planet. But it' s fallen prey to fishermen' s hooks and nets. Surveys suggest oceanic whitetips may have declined by a staggering 99. It' s like the disappearance of bison from America' s Great Plains, yet it' s only happened in the past 50 years, and almost no one has noticed. Incredibly, the world' s oceans may have lost more than 90 of their large predatory fish since industrialised fishing began. |
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jǐ bǎi wàn nián lái shā yú yī zhí tǒng zhì zhe hǎi yáng. tā men kòng zhì zhe hǎi yáng lǐ yú de shù liàng, yīn cǐ shā yú zài bǎo chí hǎi yáng shēng tài xì tǒng de jiàn kāng hé duō yàng xìng fāng miàn, bàn yǎn zhuó zhòng yào zuò yòng. zài fǎ shǔ bō lì ní xī yà, huī jiāo shā jù jí zài yì qǐ. ér shuāng jì shā zé yóu yì zài jiā lā pà gē sī qún dǎo. zhè shì nán de de jǐ gè shā yú jù jí dì. dàn shì qián shuǐ zhě shuō tā men xiàn zài kě yǐ kàn dào de shā yú shù liàng bù duō, qí shù liàng zhǐ zhàn guò qù de jǐ fēn zhī yī. xǔ duō shā yú shì" hǎi yáng yí mín", wèi le zhuī zhú liè wù, tā men néng gòu chuān yuè shù bǎi yīng lǐ, qí zhōng zuì jù dài biǎo de shì yuǎn yáng bái qí shā. lìng rén jīng qí de shì, tā men céng jīng shì zhè gè xīng qiú shàng shù liàng zuì duō de dòng wù zhī yī. rú jīn què lún wéi yú fū de liè wù, zài yú gōu hé yú wǎng de jiā jī xià nǔ lì qiú shēng. diào chá biǎo míng yuǎn yáng bái qí shā de shù liàng yǐ jīng ruì jiǎn dào yuán shù liàng de 1 le. zhè hé měi guó píng yuán shàng dà yě niú shì jiàn yī mú yī yàng. guò qù 50 nián lǐ měi guó píng yuán shàng de dà yě niú xùn sù xiāo shī què wú rén guān zhù. lìng rén nán yǐ zhì xìn de shì, dāng gōng yè huà bǔ lāo kāi shǐ zhī hòu, quán shì jiè hǎi yáng zhōng, yǒu chāo guò 90 de dà xíng bǔ liè xíng yú lèi yīn cǐ ér wáng. |