Biogeochemical responses to late-winter storms in the Sargasso Sea. IV. Rapid succession of major phytoplankton groups

Lomas, M.W., Roberts, N., Lipschultz, F., Krause, J.W., Nelson, D.M. and Bates, N.R. (2009) Biogeochemical responses to late-winter storms in the Sargasso Sea. IV. Rapid succession of major phytoplankton groups. Deep Sea Research Part I: Oceanographic Research Papers, 56 (6), 892-908. (doi:10.1016/j.dsr.2009.03.004).

Abstract

In this paper, we present multi-parameter data on phytoplankton community composition, and its response to storm events in the Sargasso Sea in late February and early March of 2 years (2004 and 2005). Observed physical conditions spanned a continuum from pulsed destratification/stratification to continuous mixing, with a corresponding range of phytoplankton growth responses. The pulsed destratification/stratification condition resulted in a rapid (1–2 d) doubling of euphotic zone chlorophyll (Chl-a) along with a rapid succession, days timescale, from diatoms to haptophytes and then to cyanobacteria. Deep (>300 m) continuous mixing led to a slow (8–9 d) doubling of autotrophic biomass with no observed succession in the phytoplankton community. These different temporal responses appear to be due to differences between nutrient-limited and light-limited phytoplankton growth, although differences in grazing rates or selective grazing cannot be ruled out. Unexpectedly, we found that flow cytometrically enumerated picoeukaryotes were not accounted for in HPLC-pigment derived phytoplankton classifications and did not covary with any of the pigments quantified. Yet, the picoeukaryotes were positively related to increases in total Chl-a and increased carbon export, suggesting an important but as yet unknown role in the Sargasso Sea carbon cycle.

This record has no associated files available for download.

Contributors

Download statistics