Diurnal vertical migration is a behaviour adopted by aquatic organisms (particularly zooplankton). It can be observed in the ocean and in lakes, and is principally thought to be an anti-predator defense. However, recent research has demonstrated that diurnal vertical migration (abbreviated as DVM) can be both a foraging strategy and may help animals optimize their metabolic cost-benefit ratio.

Some of the animals that exhibit DVM are:

• Daphnia, Copepods, Holopedium and other zooplankton;
• Larval fish, such as minnows, whitefish, smelt;
• Adult fish, such as rainbow trout;
• Assorted other invertebrates.