Otolith chemistry reveals painted notie (Nototheniops larseni) juvenile stocks differed between southern Bransfield Strait and South Georgia shelf

Abstract

The painted notie Nototheniops larseni is a link between the lower and upper levels of food web as one of the most abundant and widespread fish species in the Southern Ocean. Otolith chemistry is a well-established approach for studying fish life histories and differentiating stock structure, and chemical analysis of otolith core can be used to distinguish fish stocks. This study demonstrates that the N. larseni juvenile stocks in the southern Bransfield Strait are sourced from the same environment, but the stocks in the southern Bransfield Strait and at South Georgia shelf are separated geographically using chemical data from otolith core, hatching and feeding checks, and edge. The ratios of ⁷Li to ⁴²Ca across otolith sections of N. larseni juveniles in the southern Bransfield Strait are lower significantly than those at the South Georgia shelf, indicating the Li in fish otolith may act as a chemical tag for reflecting sea ice dynamics in the Southern Ocean.