Adaptation of phytoplankton communities to mesoscale eddies in the Mozambique Channel

Abstract An investigation of phytoplankton pigment and absorption characteristics was undertaken during three research cruises in the Mozambique Channel to elucidate community structure and examine the adaptation of populations to mesoscale features at the surface and the deep chlorophyll maximum (DCM). Total chlorophyll a concentration (TChla) at the surface was determined to be greater in cyclonic eddies than in anticyclones, while TChla in divergence and shelf zones were similar to cyclones, with frontal zones being slightly lower. TChla at the DCM was similar for all categories, although there was a tendency for anticyclones to have lower TChla. Prokaryotes were the most significant phytoplankton group at the surface, with small flagellates also being of secondary importance, while flagellates dominated at the DCM. A few shelf stations, and frontal and shelf stations close to the shelf, displayed high TChla and diatom domination, particularly at the DCM. Absorption properties and photopigment indices revealed that prokaryote dominated communities had high chlorophyll-specific absorption coefficients, a large range in the proportion of TChla within the total pigment pool and a high proportion of photoprotective carotenoids. Diatoms had low chlorophyll-specific absorption, a relatively high proportion of TChla, and elevated proportions of photosynthetic carotenoids and chlorophyll c. Flagellate dominated communities had intermediate chlorophyll-specific absorption, a lower proportion of TChla, elevated photosynthetic carotenoids and intermediate chlorophyll c.

[1]  J. Ryther,et al.  Primary Organic Production in Relation to the Chemistry and Hydrography of the Western Indian OCEAN1 , 1966 .

[2]  Tarron Lamont,et al.  Characterisation of mesoscale features and phytoplankton variability in the Mozambique Channel , 2014 .

[3]  F. Marsac,et al.  Patterns of variability of sea surface chlorophyll in the Mozambique Channel: A quantitative approach , 2009 .

[4]  Johann R. E. Lutjeharms,et al.  Observations of the flow in the Mozambique Channel , 2002 .

[5]  Tommy D. Dickey,et al.  The transient oasis: Nutrient-phytoplankton dynamics and particle export in Hawaiian lee cyclones , 2008 .

[6]  C. Carlson,et al.  Microbial dynamics in cyclonic and anticyclonic mode-water eddies in the northwestern Sargasso Sea , 2008 .

[7]  Annick Bricaud,et al.  Natural variability of phytoplanktonic absorption in oceanic waters: Influence of the size structure of algal populations , 2004 .

[8]  Graham D. Quartly,et al.  Eddies in the southern Mozambique Channel , 2004 .

[9]  Collin S. Roesler Theoretical and experimental approaches to improve the accuracy of particulate absorption coefficients derived from the quantitative filter technique , 1998 .

[10]  Paul G. Falkowski,et al.  Photosynthetic community responses to upwelling in mesoscale eddies in the subtropical North Atlantic and Pacific Oceans , 2008 .

[11]  H. Bouman,et al.  Water-column stratification governs the community structure of subtropical marine picophytoplankton. , 2011, Environmental microbiology reports.

[12]  M. Zapata,et al.  Microalgal classes and their signature pigments , 2011 .

[13]  S. Kooijman,et al.  The interpretation of satellite chlorophyll observations: The case of the Mozambique Channel , 2009 .

[14]  C. D. B. Montégut,et al.  Basin-wide seasonal evolution of the Indian Ocean's phytoplankton blooms , 2007 .

[15]  Michel Potier,et al.  Foraging strategy of a top predator in tropical waters: great frigatebirds in the Mozambique Channel , 2004 .

[16]  M. Follows,et al.  Modelling the effects of chromatic adaptation on phytoplankton community structure in the oligotrophic ocean , 2010 .

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

[18]  H. Claustre,et al.  Vertical distribution of phytoplankton communities in open ocean: An assessment based on surface chlorophyll , 2006 .

[19]  Lisa R. Moore,et al.  Utilization of different nitrogen sources by the marine cyanobacteria Prochlorococcus and Synechococcus , 2002 .

[20]  Patrice Klein,et al.  Impact of sub-mesoscale physics on production and subduction of phytoplankton in an oligotrophic regime , 2001 .

[21]  A. Weidemann,et al.  Quantifying absorption by aquatic particles: A multiple scattering correction for glass-fiber filters , 1993 .

[22]  P. Morin,et al.  Northern and southern water masses in the equatorial Atlantic: distribution of nutrients on the WOCE A6 and A7 lines , 1998 .

[23]  H. Claustre,et al.  Prochlorococcus and Synechococcus: A comparative study of their optical properties in relation to their size and pigmentation , 1993 .

[24]  P. Leeuwen,et al.  MARE and ACSEX: new research programmes on the Agulhas Current System , 2000 .

[25]  R. Barlow,et al.  Phytoplankton production and physiological adaptation on the southeastern shelf of the Agulhas ecosystem , 2010 .

[26]  A. Robinson,et al.  Eddy-induced nutrient supply and new production in the Sargasso Sea , 1997 .

[27]  Manesh Shah,et al.  Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche differentiation , 2003, Nature.

[28]  H. Claustre,et al.  Extreme diversity in noncalcifying haptophytes explains a major pigment paradox in open oceans , 2009, Proceedings of the National Academy of Sciences.

[29]  N. Welschmeyer Fluorometric analysis of chlorophyll a in the presence of chlorophyll b and pheopigments , 1994 .

[30]  J. Raven,et al.  Picophytoplankton : Bottom-up and top-down controls on ecology and evolution , 2005 .

[31]  M. Zubkov,et al.  Ultraplankton distribution in surface waters of the Mozambique Channel — flow cytometry and satellite imagery , 2003 .

[32]  F. Marsac,et al.  Influence of mesoscale eddies on spatial structuring of top predators’ communities in the Mozambique Channel , 2010 .

[33]  Johann R. E. Lutjeharms The Agulhas Current , 2006 .

[34]  R. Bidigare,et al.  Depth-stratified phytoplankton dynamics in Cyclone Opal, a subtropical mesoscale eddy , 2008 .

[35]  Robert R. Bidigare,et al.  Diatoms in the desert: Plankton community response to a mesoscale eddy in the subtropical North Pacific , 2008 .

[36]  Dale A. Kiefer,et al.  Chlorophyll α specific absorption and fluorescence excitation spectra for light-limited phytoplankton , 1988 .

[37]  A. Bricaud,et al.  Spectral absorption coefficients of living phytoplankton and nonalgal biogenous matter: A comparison between the Peru upwelling areaand the Sargasso Sea , 1990 .

[38]  P. Bach,et al.  The Mozambique Channel: From physics to upper trophic levels , 2014 .

[39]  Frédéric Partensky,et al.  Accelerated evolution associated with genome reduction in a free-living prokaryote , 2005, Genome Biology.

[40]  Hervé Claustre,et al.  Phytoplankton pigment distribution in relation to upper thermocline circulation in the eastern Mediterranean Sea during winter , 2001 .

[41]  Mark A Moline,et al.  CORRELATED EVOLUTION OF GENOME SIZE AND CELL VOLUME IN DIATOMS (BACILLARIOPHYCEAE) 1 , 2008, Journal of phycology.

[42]  S. Pesant,et al.  Contrasting the vertical differences in the phytoplankton biology of a dipole pair of eddies in the south-eastern Indian Ocean , 2007 .

[43]  P. Leeuwen,et al.  Eddies and variability in the Mozambique Channel , 2003 .