@article{fdi:010067988,
  title = {{B}arium and molybdenum records in bivalve shells : geochemical proxies for phytoplankton dynamics in coastal environments ?},
  author = {{T}h{\'e}bault, {J}. and {C}hauvaud, {L}. and {L}'{H}elguen, {S}. and {C}lavier, {J}. and {B}arats, {A}. and {J}acquet, {S}{\'e}verine and {P}echeyran, {C}. and {A}mouroux, {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}arium : calcium and molybdenum : calcium ratios were investigated in shells of the tropical scallop {C}omptopallium radula. {T}hree juvenile specimens were harvested alive in the southwest lagoon of {N}ew {C}aledonia after a 1-yr hydrological survey. {C}alcite samples representing a few hours of biomineralization were laser-ablated along the maximal growth axis and analyzed for {B}a and {M}o content with an inductively coupled plasma mass spectrometer. {A}bsolute dates of shell precipitation assigned on the basis of periodic formation of shell growth patterns led to the accurate reconstruction of ontogenetic variations of elemental ratios with subweekly resolution. {I}nterindividual variability of {B}a : {C}a and {M}o: {C}a time series was low, indicating an environmental control on the incorporation of these elements within shells. {B}oth profiles were characterized by a background level punctuated by sharp peaks. {T}he ingestion of diatoms enriched in {B}a (adsorbed on iron oxyhydroxides associated with the frustules) is the most likely cause of the formation of {B}a : {C}a peaks. {S}ome contribution of diatom-associated barite is also possible. {I}n every instance, {B}a : {C}a would possibly be a proxy for the timing and magnitude of diatom blooms. {A}mong all the theories that could be advanced to explain the occurrence of {M}o : {C}a peaks, the most plausible appears to be the ingestion of phytoplankton cells grown on {NO}3-, and therefore containing high levels of {M}o required for the activity of nitrate reductase. {I}f this is so, then {M}o : {C}a could be a new proxy for nitrate uptake by phytoplankton in coastal ecosystems, helping to reconstruct the balance between new and regenerated production in paleoenvironments.},
  keywords = {},
  booktitle = {},
  journal = {{L}imnology and {O}ceanography},
  volume = {54},
  numero = {3},
  pages = {1002--1014},
  ISSN = {0024-3590},
  year = {2009},
  DOI = {10.4319/lo.2009.54.3.1002},
  URL = {https://www.documentation.ird.fr/hor/fdi:010067988},
}