We sometimes call reverse diel vertical migrations.

我们有时称反向昼夜垂直迁移。

It's called the diel vertical migration or DVM for short.

它被称为昼夜垂直迁移或简称 DVM。

Just like those early observers of diel vertical migration, we're using sound.

就像那些早期观察昼夜垂直迁移的人一样，我们使用的是声音。

And all that makes studying the diel vertical migration even more critical.

所有这些使得研究昼夜垂直迁移变得更加重要。