* Phytoplankton are microscopic plants that drift in the ocean. They are the primary producers in the ocean food chain, and they are eaten by zooplankton.
* Zooplankton are small animals that drift in the ocean. They eat phytoplankton and are eaten by fish.
* Fish are larger animals that live in the ocean. They eat zooplankton and are eaten by puffins.
* Puffins are seabirds that eat fish. They are predators at the top of the ocean food chain.