posted on 2023-05-21, 11:20authored byL Ratnarajah, Blain, S, Philip BoydPhilip Boyd, Fourquez, M, Obernosterer, I, Tagliabue, A
Across the Southern Ocean, phytoplankton growth is governed by iron and light, while bacterial growth is regulated by iron and labile dissolved organic carbon (LDOC). We use a mechanistic model to examine how competition for iron between phytoplankton and bacteria responds to changes in iron, light, and LDOC. Consistent with experimental evidence, increasing iron and light encourages phytoplankton dominance, while increasing LDOC and decreasing light favors bacterial dominance. Under elevated LDOC, bacteria can outcompete phytoplankton for iron, most easily under lower iron. Simulations reveal that bacteria are major iron consumers and suggest that luxury storage plays a key role in competitive iron uptake. Under seasonal conditions typical of the Southern Ocean, sources of LDOC besides phytoplankton exudation modulate the strength of competitive interactions. Continued investigations on the competitive fitness of bacteria in driving changes in primary production in iron-limited systems will be invaluable in refining these results.
History
Publication title
Geophysical Research Letters
Volume
48
Pagination
1-11
ISSN
0094-8276
Department/School
Institute for Marine and Antarctic Studies
Publisher
Amer Geophysical Union
Place of publication
2000 Florida Ave Nw, Washington, USA, Dc, 20009
Rights statement
Copyright 2020 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Repository Status
Open
Socio-economic Objectives
Measurement and assessment of marine water quality and condition