@article{PAR00007479,
  title = {{E}ffects of an iron-light co-limitation on the elemental composition ({S}i, {C}, {N}) of the marine diatoms {T}halassiosira oceanica and {D}itylum brightwellii},
  author = {{B}ucciarelli, {E}va and {P}ondaven, {P}. and {S}arthou, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e examined the effect of iron ({F}e) and {F}e-light ({F}e-{L}) co-limitation on cellular silica ({BS}i), carbon ({C}) and nitrogen ({N}) in two marine diatoms, the small oceanic diatom {T}halassiosira oceanica and the large coastal species {D}itylum brightwellii. {W}e showed that {C} and {N} per cell tend to decrease with increasing {F}e limitation (i.e. decreasing growth rate), both under high light ({HL}) and low light ({LL}). {W}e observed an increase ({T}. oceanica, {LL}), no change ({T}. oceanica, {HL}) and a decrease ({D}. brightwellii, {HL} and {LL}) in {BS}i per cell with increasing degree of limitation. {T}he comparison with literature data showed that the trend in {C} and {N} per cell for other {F}e limited diatoms was similar to ours. {I}nterspecific differences in {C} and {N} quotas of {F}e limited diatoms observed in the literature seem thus to be mostly due to variations in cell volume. {O}n the contrary, there was no global trend in {BS}i per cell or per cell volume, which suggests that other interspecific differences than {F}e-induced variations in cell volume influence the degree of silicification. {T}he relative variations in {C}:{N}, {S}i:{C} and {S}i:{N} versus the relative variation in specific growth rate (i.e. mu:mu(max)) followed the same patterns for {T}. oceanica and {D}. brightwellii, whatever the irradiance level. {H}owever, the variations of {C}:{N} under {F}e limitation reported in the literature for other diatoms are contrasted, which may thus be more related to growth conditions than to interspecific differences. {A}s observed in other studies, {S}i:{C} and {S}i:{N} ratios increased by more than 2-fold between 100% and 40% of mu(max). {U}nder more severe limitation ({HL} and {LL}), we observed for the first time a decrease in these ratios. {T}hese results may have important biogeochemical implications on the understanding and the modelling of the oceanic biogeochemical cycles, e.g. carbon and silica export. [{B}ucciarelli, {E}.] {U}niv {E}uropeenne {B}retagne, {R}ennes, {F}rance; {U}niv {B}rest, {CNRS}, {IUEM}, {IRD},{LEMAR},{UMR} 6539, {F}-29280 {P}louzane, {F}rance {B}ucciarelli, {E}, {U}niv {E}uropeenne {B}retagne, {R}ennes, {F}rance eva.bucciarelli@univ-brest.fr {E}uropean {C}ommission [{EVK}2-1999-00227]; {BOA} [{ANR}-05-{BLAN}-0153] {T}he authors would like to thank two anonymous reviewers and {D}. {H}utchins for their insightful comments which improved this manuscript. {T}his work was funded by the support from the {E}uropean {C}ommission's {M}arine {S}cience and {T}echnology {P}rogramme under {C}ontract {EVK}2-1999-00227 ({IRONAGES}, "{I}ron {R}esources and {O}ceanic {N}utrients - {A}dvancements of {G}lobal {E}nvironment {S}imulations") and the {BOA} project ({ANR}-05-{BLAN}-0153). {T}he iron concentration in the background medium was measured by {M}. {G}allinari. {A}. {M}asson performed carbon and nitrogen measurements. {J}. {H}elias is thanked for his help with the {F}e limited cultures of {T}. oceanica.},
  keywords = {{ATLANTIQUE} {NORD} ; {PACIFIQUE} {NORD}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {7},
  numero = {},
  pages = {657--669},
  year = {2010},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00007479},
}