Removing the mud, uncovering gravel beds where fish spawn, and finding suitable salmon types to rebuild the population is a daunting task.

清除淤泥，发现鱼类产卵的砾石层，找到合适的鲑鱼种类来重建种群是一项艰巨的任务。

youdao

There are biologists throughout the state constantly monitoring adult fish as they show up to spawn.

整个州都有生物学家在成年鱼出来产卵的时候持续监测着它们。

youdao

Some fish do not spawn until maturity. If you catch them before that and you've no baby fish produced for the next year.

有些鱼要到成熟期才产卵。如果你在成熟期之前就开始捕捞，那么你明年就没有鱼籽了。

youdao

"These are the habitats that provide really valuable places for the fish to get together, to aggregate,to spawn, so they are the bases of the fisheries."

VOA: standard.2010.05.26

The boats of both countries take fish returning to spawn in the rivers of either.

ECONOMIST: Canada

The Angling Trust said it was disappointed after none of 72 fish electronically tagged negotiated the barrage to migrate up river to spawn.

BBC: Fears over Tees Barrage impact on fish

Coral-reef fish tend to grow slowly, take many years to reach reproductive age, and then spawn in only a few localised sites.

ECONOMIST: What price coral?