Distributions of krill and Antarctic silverfish and correlations with environmental variables in the western Ross Sea, Antarctica

Lb Davis,Ee Hofmann,Jm Klinck,Ms Dinniman,A Piñones

doi:10.3354/meps12347

Abstract

Distributions of krill and Antarctic silverfish and correlations with environmental variables in the western Ross Sea, Antarctica

Highlights

The Ross Sea is among the most biologically productive regions within the Southern Ocean (Arrigo et al 1998b, 2008), contributing about 35% (23.4 ± 9.98 Tg C yr −1 [mean ± SD]) of the annual Southern Ocean shelf production (66.1 Tg C yr−1; Arrigo et al 2008)
Crystal krill and Antarctic silverfish are associated with sea ice, which provides food and a nursery region for eggs and early life stages (Laws 1985, Kellermann 1986b, Daly & Macaulay 1988), and these ice-obligate species tend to be found in neritic, ice-covered regions (Hubold 1984, Kellermann 1986a, Thomas & Green 1988, Hosie 1991, Pakhomov & Perissinotto 1996)
For Antarctic krill, the presence of warm Circumpolar Deep Water (CDW) at depth is essential for completion of their early life history (Hofmann et al 1992, Hofmann & Hüsrevoglu 2003), and this species tends to be found in regions where CDW is present (Quetin & Ross 1984, Azzali & Kalinowski 2000, Sala et al 2002, Ashjian et al 2004, Lawson et al 2004)

Summary

Introduction

The Ross Sea is among the most biologically productive regions within the Southern Ocean (Arrigo et al 1998b, 2008), contributing about 35% (23.4 ± 9.98 Tg C yr −1 [mean ± SD]) of the annual Southern Ocean shelf production (66.1 Tg C yr−1; Arrigo et al 2008). For Antarctic krill, the presence of warm Circumpolar Deep Water (CDW) at depth is essential for completion of their early life history (Hofmann et al 1992, Hofmann & Hüsrevoglu 2003), and this species tends to be found in regions where CDW is present (Quetin & Ross 1984, Azzali & Kalinowski 2000, Sala et al 2002, Ashjian et al 2004, Lawson et al 2004) These general distributions exhibit considerable spatial variability between seasons and across the Southern Ocean (Azzali & Kalinowski 2000, Siegel 2005, Lawson et al 2008, Murphy et al 2017). Understanding the factors influencing current krill and Antarctic silverfish distributions will allow projections of distributional changes in response to changing environmental conditions in the Ross Sea (e.g. Smith et al 2014b)

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Conclusion