Microbial control of diatom bloom dynamics in the open ocean
journal contributionposted on 2023-05-18, 04:02 authored by Philip BoydPhilip Boyd, Robert StrzepekRobert Strzepek, Chiswell, S, Chang, H, DeBruyn, JM, Ellwood, M, Keenan, s, King, AL, Maas, EW, Nodder, S, Sander, SG, Sutton, P, Twining, BS, Wilhelm, SW, Hutchins, DA
Diatom blooms play a central role in supporting foodwebs and sequestering biogenic carbon to depth. Oceanic conditions set bloom initiation, whereas both environmental and ecological factors determine bloom magnitude and longevity. Our study reveals another fundamental determinant of bloom dynamics. A diatom spring bloom in offshore New Zealand waters was likely terminated by iron limitation, even though diatoms consumed <1/3 of the mixed-layer dissolved iron inventory. Thus, bloom duration and magnitude were primarily set by competition for dissolved iron between microbes and small phytoplankton versus diatoms. Significantly, such a microbial mode of control probably relies both upon out-competing diatoms for iron (i.e.,K-strategy), and having high iron requirements (i.e.,r-strategy). Such resource competition for iron has implications for carbon biogeochemistry, as, blooming diatoms fixed three-fold more carbon per unit iron than resident non-blooming microbes. Microbial sequestration of iron has major ramifications for determining the biogeochemical imprint of oceanic diatom blooms.
Publication titleGeophysical Research Letters
Department/SchoolInstitute for Marine and Antarctic Studies
PublisherAmer Geophysical Union
Place of publication2000 Florida Ave Nw, Washington, USA, Dc, 20009
Rights statementCopyright 2012 American Geophysical Union.