Preview

PDF 141293 - The ro...pdf | Download (1MB) | Preview

Abstract

Marine ecosystems regulate atmospheric carbon dioxide levels by transporting andstoring photosynthetically fixed carbon in the ocean’s interior. In particular, thesubantarctic and polar frontal zone of the Southern Ocean is a significant regionfor physically driven carbon uptake due to mode water formation, although it isunder-studied concerning biologically mediated uptake. Regional differences in ironconcentrations lead to variable carbon export from the base of the euphotic zone.Contrary to our understanding of export globally, where high productivity results inhigh export, naturally iron-fertilized regions exhibit low carbon export relative to theirsurface productivity, while HNLC (High Nutrient, Low Chlorophyll) waters emerge asa significant area for carbon export. Zooplankton, an integral part of the oceanicfood web, play an important role in establishing these main carbon export regimes.In this mini review, we explore this role further by focusing on the impact of grazingand the production of fecal pellets on the carbon flux. The data coverage in thesubantarctic region will be assessed by comparing two case studies - the iron-repleteKerguelen Plateau and the HNLC region south of Australia. We then discusschallenges in evaluating the contributions of zooplankton to carbon flux, namelygaps in seasonal coverage of sampling campaigns, the use of non-standardized andbiased methods and under-sampling of the mesopelagic zone, an important area ofcarbon remineralization. More integrated approaches are necessary to improve presentestimates of zooplankton-mediated carbon export in the Southern Ocean.

Item Type:	Article
Authors/Creators:	Halfter, S and Cavan, EL and Swadling, KM and Eriksen, RS and Boyd, PW
Keywords:	biological carbon pump, zooplankton, southern ocean, subpolar, carbon cycle
Journal or Publication Title:	Frontiers in Marine Science
Publisher:	Frontiers Research Foundation
ISSN:	2296-7745
DOI / ID Number:	https://doi.org/10.3389/fmars.2020.567917
Copyright Information:	Copyright 2020 Halfter, Cavan, Swadling, Eriksen and Boyd. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/
Related URLs:	Google Scholar: Halfter, S UTAS Profile: Swadling, KM Google Scholar: Boyd, PW UTAS Profile: Boyd, PW
Item Statistics:	View statistics for this item

Actions (login required)

Item Control Page