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Otolith nucleus chemistry distinguishes Electrona antarctica in the westward-flowing Antarctic Slope Current and eastward-flowing Antarctic Circumpolar Current off East Antarctica

Citation

Zhu, G and Duan, M and Ashford, JR and Wei, L and Zhou, M and Bestley, S, Otolith nucleus chemistry distinguishes Electrona antarctica in the westward-flowing Antarctic Slope Current and eastward-flowing Antarctic Circumpolar Current off East Antarctica, Marine Environmental Research, 142 pp. 7-20. ISSN 0141-1136 (2018) [Refereed Article]

Copyright Statement

© 2018 Elsevier Ltd. All rights reserved.

DOI: doi:10.1016/j.marenvres.2018.09.010

Abstract

Eastward transport in the Southern Ocean is concentrated in jets associated with fronts in the Antarctic Circumpolar Current (ACC), whereas flow along the Antarctic continental slope is strongly westward in the Antarctic Slope Current (ASC). The dominant mesopelagic fish endemic to the Southern Ocean, Electrona antarctica (GŁnther, 1878), has been linked to Circumpolar Deep Water (CDW) transported by the ACC, and a modified version of CDW associated with the ASC. In conjunction with a regional-scale hydrographic survey south of the Kerguelen Plateau, we sampled fish from the ACC and ASC across Princess Elizabeth Trough off East Antarctica, and examined their otolith chemistry. Material laid down in the nucleus during early life showed heterogeneity, arguing against a single homogeneous population. Instead, it suggested exposure to different environments after hatching, consistent with separate transport pathways along the ACC and ASC. Despite clear differences between stations documented in the survey, material laid down along the edge did not show heterogeneity, suggesting instead exposure to similar environments. Seasonal movement northward by ASC fish into the ACC may explain both these results, and potential physical mechanisms include circulation in the Australian-Antarctic Gyre; northward movement of slope waters along the eastern margin of Princess Elizabeth Trough; and seasonal extension of sea-ice into the ACC. Such meridional movement would expose fish to zonal flow, eastward in the ACC during winter and westward in the ASC during summer, promoting regional retention as well as creating opportunities for mixing with fish transported along the ACC.

Item Details

Item Type:Refereed Article
Keywords:otolith chemistry, East Antarctica, Antarctic circumpolar current, Electrona antarctica, Antarctic slope front
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:Environmental Management
Objective Group:Management of Antarctic and Southern Ocean environments
Objective Field:Biodiversity in Antarctic and Southern Ocean environments
UTAS Author:Bestley, S (Dr Sophie Bestley)
ID Code:130920
Year Published:2018
Web of Science® Times Cited:6
Deposited By:Ecology and Biodiversity
Deposited On:2019-02-20
Last Modified:2019-03-25
Downloads:0

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