A biogeochemical study of the coccolithophore, Emiliania huxleyi, in the North Atlantic

Abstract

The biogeochemical properties of an extensive bloom (∼250,000 km2) of the coccolithophore, Emiliania huxleyi, in the north east Atlantic Ocean were investigated in June 1991. Satellite (NOAA‐AVHRR) imagery showed that the bloom was centered initially at 60°–63°N by 13°–28°W and lasted approximately 3 weeks. Spatial variations in satellite‐measured reflectance were well correlated with surface measurements of the beam attenuation coefficient, levels of particulate inorganic carbon, and coccolith density. Rates of both photosynthesis and calcification were typically relatively low within the coccolithophore‐rich waters, suggesting the population was in a late stage of development at the time of the field observations. Levels of dimethyl sulphide (DMS) in surface waters were high compared to average ocean values, with the greatest concentrations in localized areas characterized by relatively high rates of photosynthesis, calcification, and grazing by microzooplankton. The estimated spatially averaged flux of DMS to the atmosphere was 1122 nmol m−2 h−1, somewhat greater than that determined for the same region in June‐July 1987. Coccolith production (1 × 106 tonnes calcite‐C) had a significant impact on the state of the CO2 system, causing relative increases of up to 50 μatm in surface pCO2 in association with alkalinity and water temperature changes. Gradients in pCO2 were as great as 100 μatm over horizontal distances of 20–40 km. The environmental implications of these findings are discussed in relation to the spatial and temporal distributions of E. huxleyi.

Pilot study of an EST approach of the coccolithophorid Emiliania huxleyi during a virus infection

“…It is well known for its immense coastal and open ocean blooms ranging from sub-polar to tropical latitudes (Balch et al, 1992;Brown and Yoder 1994) that can cover 10,000 km 2 or more (Holligan et al, 1993, Winter et al, 1994. E. huxleyi is also regarded as a major sink for calcium carbonate in the ocean (Eide 1990, Samtleben and Bickert 1990, Baumann et al, 2004.…”

Phytoplankton community dynamics during late spring coccolithophore blooms at the continental margin of the Celtic Sea (North East Atlantic, 2006–2008)

“…This is most probably due to complex interplay between the dynamics of internal tidal mixing, mixed layer shoaling (higher on the shelf than the slope, Tables 3 and SP4), and meteorological conditions. Moreover, loss factors such as grazing (Holligan et al, 1993;Fileman et al, 2002;Painter et al, 2010b), viral lysis (Bratbak et al, 1996;Wilson et al, 2002) and enhanced export through aggregation (Boyd et al, 2005; Schmidt et al, in press) would further influence the distribution of phytoplankton biomass Fig. 4.…”

VERTIGO (VERtical Transport In the Global Ocean): A study of particle sources and flux attenuation in the North Pacific

“…Thus physical controls on the depth of the euphotic zone and surface mixed layer plus the extent of upper ocean ventilation can affect the export of particulate carbon . The extent of POC and particulate inorganic carbon (PIC) partitioning on sinking particles with depth is also critical for understanding ocean C uptake, since photosynthesis and the production of POC decreases surface ocean pCO 2 , while production of calcium carbonate (calcite and aragonite), which are the main forms of PIC, would ultimately increase pCO 2 (Holligan et al, 1993;Antia et al, 1999;Francois et al, 2002;Berelson et al, 2007).…”