The dense shoals, on which so many depend gather only when water conditions are perfect. 只有在水况非常好的情况下 才会出现这样的鱼群聚集

30. Even they can end up in the whale shark's stomach.
    除非它们想成为鲸鲨的腹中美餐
31. Predators here must grab what they can, when they can
    掠食者在这里想怎么吃就怎么吃
32. for such events do not last long.
    因为好事不多,好景不长
33. The dense shoals, on which so many depend gather only when water conditions are perfect.
    只有在水况非常好的情况下 才会出现这样的鱼群聚集
34. Many predators spend much of their time cruising the open ocean
    许多掠食者把大部分的时间用在来回巡游
35. endlessly searching.
    寻找食物上
36. Plankton feeding rays do so,
    吃浮游生物的蝠鲼也是

来自《行星地球 第一季 第十一集 Planet Earth S01E11 海洋深处》第 33 行