Copepods are one of the most common zooplankton in the Chukchi Sea. The scientists on this cruise have been seeing more of them than any other zooplankton. Most copepods graze on phytoplankton but some species also eat smaller zooplankton. They have 12 life stages and take two years to mature. One of the most common copepods here, Calanus glacialis builds up large fat deposits by eating a lot of phytoplankton during the spring and summer blooms and then spends the winter in very deep water in a state of hibernation called diapause where they sink to the bottom in large groups and live off their stored fat. They are an important food for bowhead whales.