狡猾的海狮不断吞吃回游的三文鱼，让鱼类生物学家十分困惑。

Crafty Sea Lion Befuddles Fish Biologists by Continuing to Munch on Migrating Salmon.

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科学家研究过鱼类远距离回游的现象。

Scientists have studied the migration of fish over long distances.

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在鱼蟹回游通道筑坝，要建造相应的过鱼设施。

Dams to be built across fish and crab migration routes shall be provided with appropriate fish passage facilities.

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