Ross seal distribution in the Weddell Sea : fact and fallacy

Abstract

The presence of Ross seals (Ommatophoca rossii) throughout the Weddell Sea is at best equivocal although overview articles usually depict this as fact on distribution maps. This study reviewed the appropriate literature on the distribution of Ross seals in the Weddell Sea sensu lato and investigated their presence/absence during two expeditions (summer/autumn of 2014 and 2018) into its most southern reaches off the Filchner-Ronne Ice Shelf. Both ship-board and helicopter surveys were done primarily along the eastern aspect and the south-western limit of the Weddell Sea. Evidence suggests that Ross seals are absent from the Weddell Sea during winter, utilizing the northernmost fringes of the pack-ice during the spring breeding (pupping and mating) season. Ross seals are absent from the inner reaches of the Weddell Sea past about 73° S in summer and early autumn when they occur in number in the eastern Weddell Sea eastwards from about 30° W longitude.