Squid as Predators on Krill (Euphausia superba) and Prey for Sperm Whales in the Southern Ocean

Abstract

This chapter deals with information on the role of squid, and on feeding by sperm whales on squid, in the Antarctic. Seasonal variation in the vertical distribution of krill swarms may possibly affect the distribution of smaller squid which feed on krill. Larger squid are distributed in deeper water layers where they do not feed on krill alone. Sperm whales eat larger squid in the deeper waters of the Southern Ocean. The diet of these larger squid is unknown. It is suggested that the food chain from krill to sperm whale has several links, including fish and squid. The importance of studies on deep-sea systems in the Southern Ocean is emphasized.