@article{fdi:010081499,
  title = {{D}iversity and abundance of diazotrophic cyanobacteria in the central coastal area of the {G}ulf of {G}abes ({S}outh-eastern {T}unisia)},
  author = {{H}amza, {I}. {S}. and {B}iegala, {I}sabelle and {Z}ouari, {A}. {B}. and {A}krout, {F}. and {K}eskes, {F}. {A}. and {H}amza, {A}. and {H}assen, {M}. {B}.},
  editor = {},
  language = {{ENG}},
  abstract = {{G}abes {G}ulf is limited by ultra-oligotrophic waters which are regularly fertilized with both phosphate and iron enriched atmospheric dust. {D}espite the lack of river run nitrogen source, an essential nutrient for the ecosystem productivity. {D}iazotrophic cyanobacteria are an important source of new nitrogen in oligotrophic oceans and seas. {S}o far only the filamentous diazotrophic cyanobacteria {T}richodesmium spp. has been investigated in {G}abes gulf, while it is known that other diazotrophic cyanobacteria, such as the heterocysted {R}ichelia intracellularis and unicellular cyanobacteria ({UCYN}), are major source of new nitrogen in oligotrophic ecosystems. {I}n this study, we investigated the diversity and abundance of marine diazotrophic cyanobacteria within two size fractions (> 10 mu m and 0.2-3 mu m) during {J}uly in the central coastal area of the {G}ulf of {G}abes. {R}ichelia intracellularis were present under free living and hosted in the diatoms {H}emiaulus hauckii. {U}nicellular diazotrophic cyanobacteria were classified under tow size classes (small cells: 0.8-1.5 mu m and large cells: 1.6-3.2 mu m) with a predominance of the small cells (98 %). {R}ichelia intracellularis reached concentrations that can be considered as a bloom phenomenon (up to 227.5 cells m{L}(-1)), while the concentration of {UCYN} (from 8.8 to 23.9 cells m{L}(-1)) were slightly higher than mean concentrations observed across the {M}editerranean {S}ea. {H}igh temperature and dissolved nitrogen and orthophosphate concentrations in the central coastal area of the {G}ulf of {G}abes seem to the main factors leading to such abundances. {C}ontribution of each diazotrophic cyanobacteria to the {N}/{P} balance in the central coastal area of {G}ulf was also discussed.},
  keywords = {{D}iazotrophic cyanobacteria ; {R}ichelia intracellularis ; {UCYN} ; {C}entral coastal area of the {G}ulf of {G}abes ; {TUNISIE} ; {MEDITERRANEE} ; {GABES} {GOLFE}},
  booktitle = {},
  journal = {{R}egional {S}tudies in {M}arine {S}cience},
  volume = {42},
  numero = {},
  pages = {101653 [10 ]},
  ISSN = {2352-4855},
  year = {2021},
  DOI = {10.1016/j.rsma.2021.101653},
  URL = {https://www.documentation.ird.fr/hor/fdi:010081499},
}