Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 1: Seasonal dynamics of particulate organic carbon export from a moored sediment trap


Contact
ian.salter [ at ] awi.de

Abstract

A sediment trap moored in the naturally iron-fertilized Kerguelen Plateau in the Southern Ocean provided an annual record of particulate organic carbon and nitrogen fluxes at 289 m. At the trap deployment depth, current speeds were typically low (~ 10 cm s−1) and primarily tidal-driven (M2 tidal component). Although advection was weak, the sediment trap may have been subject to hydrodynamical and biological (swimmer feeding on trap funnel) biases. Particulate organic carbon (POC) flux was generally low (< 0.5 mmol m−2 d−1), although two episodic export events (< 14 days) of 1.5 mmol m−2 d−1 were recorded. These increases in flux occurred with a 1-month time lag from peaks in surface chlorophyll and together accounted for approximately 40% of the annual flux budget. The annual POC flux of 98.2 ± 4.4 mmol m−2 yr−1 was low considering the shallow deployment depth but comparable to independent estimates made at similar depths (~ 300 m) over the plateau, and to deep-ocean (> 2 km) fluxes measured from similarly productive iron-fertilized blooms. Although undertrapping cannot be excluded in shallow moored sediment trap deployment, we hypothesize that grazing pressure, including mesozooplankton and mesopelagic fishes, may be responsible for the low POC flux beneath the base of the winter mixed layer. The importance of plankton community structure in controlling the temporal variability of export fluxes is addressed in a companion paper.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Peer revision
Scopus/ISI peer-reviewed
Publication Status
Published
Eprint ID
40441
DOI 10.519/bg-12-3153-2015

Cite as
Rembauville, M. , Salter, I. , Leblond, N. , Gueneugues, A. and Blain, S. (2015): Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 1: Seasonal dynamics of particulate organic carbon export from a moored sediment trap , Biogeosciences, 12 , pp. 3153-3170 . doi: 10.519/bg-12-3153-2015


Download
[img]
Preview
PDF
Rembauville_et_al_2015a_Biogeoscience.pdf

Download (2MB) | Preview
Cite this document as:

Share


Citation

Research Platforms
N/A

Campaigns


Actions
Edit Item Edit Item