Prokaryoplankton standing stocks in oligotrophic gyre and equatorial provinces of the Atlantic Ocean: Evaluation of inter-annual variability

Temporal changes of prokaryoplankton in three different provinces of the Atlantic Ocean were examined between 1996 and 2004. The abundance and integrated biomass of three prokaryote groups (Prochlorococcus spp., Synechococcus spp. and other prokaryoplankton) were used to detect standing stock changes in the northern and southern oligotrophic gyres and in the equatorial region. Mean cell concentrations (±standard error of the mean) of Prochlorococcus spp., Synechococcus spp. and other prokaryoplankton above the nitracline in the northern oligotrophic gyre were 1.2×105 (±0.08), 5.0×103 (±1.22) and 0.9×106 (±0.03) cells mL−1, respectively. Similar concentrations of 1.2×105 (±0.06) Prochlorococcus mL−1, 1.9×103 (±0.29) Synechococcus mL−1 and 0.7×106 (±0.03) other prokaryoplankton mL−1 were measured in the southern oligotrophic gyre, with higher concentrations of all prokaryote groups in equatorial waters. Integrated biomass (±standard error of the mean) of Prochlorococcus spp. above the nitracline was 173 (±21) mg C m−2 in the northern oligotrophic gyre, 190 (±14) mg C m−2 in the southern oligotrophic gyre and 141 (±15) mg C m−2 in the equatorial region. Synechococcus spp. biomass was lower in each of the three provinces (18 (±2), 17 (±4) and 32 (±5) mg C m−2, respectively). The data showed no statistically significant inter-annual variability in Prochlorococcus or Synechococcus abundance or integrated biomass above the nitracline in any of the provinces. The abundance and biomass of the remaining prokaryoplankton were variable, but these variations could not be ascribed to seasonal differences and did not follow a clear inter-annual trend. In light of results presented here, recommendations on the frequency and spatial resolution of sampling needed to characterise province-scale temporal variability of prokaryoplankton communities have been suggested.

[1]  D. Karl,et al.  Microbial community structure at the U.S.-Joint Global Ocean Flux Study Station ALOHA: Inverse methods for estimating biochemical indicator ratios , 1994 .

[2]  David M. Karl,et al.  The Hawaii Ocean Time-series (HOT) program: Background, rationale and field implementation , 1996 .

[3]  A. Wood,et al.  Phycoerythrin-containing picocyanobacteria in the Arabian Sea in February 1995:: diel patterns, spatial variability, and growth rates , 2001 .

[4]  E. Delong,et al.  Unsuspected diversity among marine aerobic anoxygenic phototrophs , 2002, Nature.

[5]  A. Davis.  Novel major archaebacterial group from marine plankton , 1992, Nature.

[6]  F. Lantoine,et al.  Vertical structure of picophytoplankton at different trophic sites of the tropical northeastern Atlantic Ocean , 1996 .

[7]  D. Kirchman.  Microbial ecology of the oceans , 2008 .

[8]  Francisco P. Chavez,et al.  Basin-wide distributions of living carbon components and the inverted trophic pyramid of the central gyre of the North Atlantic Ocean, summer 1993 , 1996 .

[9]  Lisa R. Moore,et al.  Photophysiology of the marine cyanobacterium Prochlorococcus: Ecotypic differences among cultured isolates , 1999 .

[10]  J. Waterbury,et al.  Biological and ecological characterization of the marine unicellular Cyanobacterium Synechococcus , 1987 .

[11]  J. Mcgowan,et al.  Mixing and oceanic productivity , 1978 .

[12]  M. Zubkov,et al.  Plankton respiration in the Eastern Atlantic Ocean , 2002 .

[13]  Zbigniew S. Kolber,et al.  Contribution of Aerobic Photoheterotrophic Bacteria to the Carbon Cycle in the Ocean , 2001, Science.

[14]  H. Ducklow,et al.  Stocks and dynamics of bacterioplankton in the northwestern Sargasso Sea , 1996 .

[15]  Lisa R. Moore,et al.  Physiology and molecular phylogeny of coexisting Prochlorococcus ecotypes , 1998, Nature.

[16]  Farooq Azam,et al.  Major role of bacteria in biogeochemical fluxes in the ocean's interior , 1988, Nature.

[17]  R. Bidigare,et al.  Long-term changes in plankton community structure and productivity in the North Pacific Subtropical Gyre: The domain shift hypothesis , 2001 .

[18]  E. Delong,et al.  Vertical distribution and phylogenetic characterization of marine planktonic Archaea in the Santa Barbara Channel , 1997, Applied and environmental microbiology.

[19]  E. Koonin,et al.  Bacterial rhodopsin: evidence for a new type of phototrophy in the sea. , 2000, Science.

[20]  P. Holligan,et al.  Phytoplankton carbon fixation chlorophyll-biomass and diagnostic pigments in the Atlantic Ocean , 2006 .

[21]  T. D. Dickey,et al.  Influence of mesoscale eddies on new production in the Sargasso Sea , 1998, Nature.

[22]  Andrew Hansen,et al.  Unicellular cyanobacteria fix N2 in the subtropical North Pacific Ocean , 2001, Nature.

[23]  G. Wolff,et al.  Physical supply of nitrogen to phytoplankton in the Atlantic Ocean , 2004 .

[24]  P. Burkill,et al.  Picoplankton community structure on the Atlantic Meridional Transect: a comparison between seasons , 2000 .

[25]  A. Rees,et al.  Nutrient distributions in an anticyclonic eddy in the northeast Atlantic Ocean, with reference to nanomolar ammonium concentrations , 2001 .

[26]  D. Vaulot,et al.  Prochlorococcus, a Marine Photosynthetic Prokaryote of Global Significance , 1999, Microbiology and Molecular Biology Reviews.

[27]  Charles R. McClain,et al.  Subtropical Gyre Variability Observed by Ocean Color Satellites , 2004 .

[28]  Jean-Marc Nicolas,et al.  Seasonal and interannual variability of ocean color and composition of phytoplankton communities in the North Atlantic, equatorial Pacific and South Pacific , 2004 .

[29]  Sallie W. Chisholm,et al.  Phytoplankton population dynamics at the Bermuda Atlantic Time-series station in the Sargasso Sea , 2001 .

[30]  K. R. Clarke,et al.  Change in marine communities : an approach to statistical analysis and interpretation , 2001 .

[31]  G. Tarran,et al.  Picoplanktonic community structure on an Atlantic transect from 50°N to 50°S , 1998 .

[32]  David M. Karl,et al.  A Sea of Change: Biogeochemical Variability in the North Pacific Subtropical Gyre , 1999, Ecosystems.

[33]  M. Behrenfeld,et al.  High variability of primary production in oligotrophic waters of the Atlantic Ocean : uncoupling from phytoplankton biomass and size structure , 2003 .

[34]  D. Vaulot,et al.  Enumeration and Cell Cycle Analysis of Natural Populations of Marine Picoplankton by Flow Cytometry Using the Nucleic Acid Stain SYBR Green I , 1997, Applied and environmental microbiology.

[35]  A. Longhurst.  Seasonal cycles of pelagic production and consumption , 1995 .

[36]  William K. W. Li.  Primary production of prochlorophytes, cyanobacteria, and eucaryotic ultraphytoplankton: Measurements from flow cytometric sorting , 1994 .

[37]  Sallie W. Chisholm,et al.  Comparative physiology of Synechococcus and Prochlorococcus: influence of light and temperature on growth, pigments, fluorescence and absorptive properties , 1995 .

[38]  Patrick M. Holligan,et al.  Basin-scale variability of phytoplankton biomass, production and growth in the Atlantic Ocean , 2000 .

[39]  S. Giovannoni,et al.  Evolution, diversity, and molecular ecology of marine prokaryotes , 2000 .

[40]  William K. W. Li,et al.  Chlorophyll, bacteria and picophytoplankton in ecological provinces of the North Atlantic , 2001 .

[41]  Wkw Li,et al.  Composition of ultraphytoplankton in the central North Atlantic , 1995 .

[42]  R. Paranhos,et al.  Bacterial Abundance and Production in the Southwest Atlantic Ocean , 2004, Hydrobiologia.

[43]  D. Vaulot,et al.  Photosynthetic picoplankton community structure in the subtropical North Pacific Ocean near Hawaii (station ALOHA) , 1993 .

[44]  D. Vaulot,et al.  Phycoerythrins in the southern tropical and equatorial Pacific Ocean: Evidence for new cyanobacterial types , 1999 .

[45]  J. Sugiyama,et al.  Detection of Seven Major Evolutionary Lineages in Cyanobacteria Based on the 16S rRNA Gene Sequence Analysis with New Sequences of Five Marine Synechococcus Strains , 1999, Journal of Molecular Evolution.