What is the ecological role of copepods and krill in the marine environment?

Planktonic copepods are important to global ecology and the carbon cycle. They are usually the dominant members of the zooplankton, and are major food organisms for small fish such as the dragonet, banded killifish, Alaska pollock, and other crustaceans such as krill in the ocean and in fresh water.

He should put sand around the spill in order to contain it so that it won't spread