And once the beavers and their dams were gone, fish populations dropped.

一旦海狸和它们创造出来的水坝都不见了，鱼类数量就会开始下降。

Oil platforms serve as excellent nursery grounds that boost fish populations, he says.

石油钻井平台就像优质育儿室，促进鱼类繁殖。

Purse seining makes it difficult to protect fish populations, he said.

他说，围网捕鱼使保护鱼类种群变得困难。

That's great for the fish population and the river otters that live here.

这对鱼及在这里生活的人们都很有帮助。

Beaches that have been mined to become barren pits, reefs and fish populations are killed.

被开采的海滩变成了贫瘠的坑，珊瑚礁和鱼类种群都被杀死了。

Environmental groups have linked the lower fish populations in the area to warming ocean temperatures.

环保组织将该地区鱼类数量减少与海洋温度升高联系在一起。

They decreased the water in the rivers, which caused the fish population in the area to decrease.

他们减少了河流中的水量，导致该地区的鱼类数量减少。

So bottom-feeding fish populations may increase, even if plankton-eating fish population decrease.

因此，即使以浮游生物为食的鱼类数量减少，底栖鱼类数量也可能会增加。

A team of scientists wanted to find out how rising sea temperatures and ocean acidification might affect these fish populations.

一个科学家小组想查明海水温度上升和海洋酸化会对这些鱼类种群造成何种数量。

Damaged reefs have a higher chance of recovery if they have healthy fish populations, the scientists wrote in the report.

受损珊瑚附近如果有健康的鱼群，那么这些珊瑚恢复健康状态的可能性就更高，科学家在这份报告中这样指出。

But for local and small fishers who depend on well-managed fish populations, it's unclear if more open measures will help.

但对于依赖管理良好的鱼类种群的当地和小渔民来说，目前还不清楚更开放的措施是否会有所帮助。

Past interventions have successfully helped depleted fish populations recover.

过去的干预措施已成功帮助枯竭的鱼类种群恢复。

Jane Lubchenco credits these programs with strengthening fish populations in the United States.

Jane Lubchenco 将这些计划归功于美国鱼类种群的增加。

With fish populations greatly reduced, many fishermen have left the waterway for work in rubber fields or factories in the city.

随着鱼类数量的大幅减少，很多渔民都离开了湄公河，在城市的橡胶地或工厂里找工作。

I guess for me, growing up in Hawaii, the changes were really with the fish population.

我想对在夏威夷长大的我来说，变化确实与鱼类数量有关。

The hope is these will help  restore fish populations and improve marine biodiversity in the area.

希望这些将有助于恢复鱼类种群并改善该地区的海洋生物多样性。

What's more, it is not so clear that the mussel is a serious threat to fish populations.

更重要的是， 贻贝是否对鱼类种群构成严重威胁尚不明确。

For example, some fish populations are plummeting because of things like commercial fishing and climate change.

例如，由于商业捕鱼和气候变化等因素， 一些鱼类的数量正在直线下降。

The goal is to get a clear picture of the fish populations of inland lakes, including Chippewa Flowage and Lac Courte Oreilles.

目标是要清楚了解内陆湖泊的鱼类种群情况，包括奇珀瓦湖和拉克库特奥里尔斯湖。

Finally, even in habitats where zebra mussels become dominant, is the overall fish population likely to decrease.

最后，即使在斑马贻贝占主导地位的栖息地， 鱼类总数也可能减少。