Planktonic cephalopods collected off East Antarctica during the ‘BROKE’ survey

Abstract

The composition and distribution of squid captured between January and March during the 1996 baseline research on oceanography, krill and the environment survey off East Antarctica (80–150°E) was investigated. A total of 195 individuals were captured. The species collected were Galiteuthis glacialis, Mesonychoteuthis hamiltoni, Histioteuthis atlantica, H. eltaninae, Alluroteuthis antarcticus, Batoteuthis skolops and Pholidoteuthis boschmai. Concentrations of squid were low, ranging from 4.4 to 174.7 individuals 100,000 −3. The majority of squid captured were G. glacialis (174 individuals, 89.2% of all squid captured), and most of these ( n=171) were small paralarvae <25 mm in mantle length. G. glacialis were distributed predominantly west of 120°E in water that was colder, and where the distance from the coastline of the southern boundary of the Antarctic circumpolar current (SB-ACC) was maximal. This water mass had greater concentrations of phytoplankton, was more productive and had maximal sea-ice extent compared to the water mass east of 120°E. G. glacialis was therefore more abundant in water where the majority of krill and krill predators were present compared to warmer oceanic waters of the ACC to the east, where salps dominated.