Moonlit Migration


During the dark winter months in the Arctic Ocean, zooplankton migrate by the light of the silvery moon. (Christian Science Monitor)

Use our fun activity to navigate plankton migration through poetry.

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit.

copepods collected from Kiel fjord in front of Liebniz Intitute of Marine Science, Scientific Name: Temora longicornis, Magnification: 5x
These clueless little copepods migrate to escape “werewolves of the deep”—predators that hunt near the moonlit surface of the ocean, where they can see prey more easily.
Photograph by David Littschwager, National Geographic

Discussion Ideas


  • During the dark Arctic winter, plankton engage in a different sort of migration: lunar vertical migration. How are the two migration patterns different?
    • Diel vertical migration follows a solar pattern, meaning it is influenced by the sun. The solar day is 24 hours long.
    • Lunar vertical migration is a lunar pattern, meaning it is influenced by the moon. The lunar day is 24.8 hours long.


  • Why do Arctic plankton change their migration pattern during the winter?
    • Arctic winters have short days when the sun is only above the horizon a brief time. Until this study, scientists pretty much thought plankton stayed put in the cold, dark mesopelagic during the winter.


  • Why do plankton migrate?
    • “They’re not just migrating for fun,” says Last. They are moving away from “werewolves of the deep”—predators that hunt near the surface of the ocean where they can see moonlit prey more easily.



Christian Science Monitor: In Arctic winter, ‘werewolves of the deep’ hunt by moonlight

CellPress Video Abstracts: Moonlight Mass Migration of Zooplankton/ Curr. Biol., Jan. 7, 2016 (Vol. 26, Issue 2)

Nat Geo: Plankton Migration/Haiku Creation

Nat Geo: Marine Mix: Small Ocean Animals Might Have a Big Influence on the World

(extra credit, and this is a tough one!) Current Biology: Moonlight Drives Ocean-Scale Mass Vertical Migration of Zooplankton during the Arctic Winter

Leave a Reply