@article{fdi:010049238,
  title = {{C}oral skeleton {P}/{C}a proxy for seawater phosphate : multi-colony calibration with a contemporaneous seawater phosphate record},
  author = {{L}a{V}igne, {M}. and {M}atthews, {K}. {A}. and {G}rottoli, {A}. {G}. and {C}obb, {K}. {M}. and {A}nagnostou, {E}. and {C}abioch, {G}uy and {S}herrell, {R}. {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A} geochemical proxy for surface ocean nutrient concentrations recorded in coral skeleton could provide new insight into the connections between sub-seasonal to centennial scale nutrient dynamics, ocean physics, and primary production in the past. {P}revious work showed that coralline {P}/{C}a, a novel seawater phosphate proxy, varies synchronously with annual upwelling-driven cycles in surface water phosphate concentration. {H}owever, paired contemporaneous seawater phosphate time-series data, needed for rigorous calibration of the new proxy, were lacking. {H}ere we present further development of the {P}/{C}a proxy in {P}orites lutea and {M}ontastrea sp. corals, showing that skeletal {P}/{C}a in colonies from geographically distinct oceanic nutrient regimes is a linear function of seawater phosphate ({PO}4 ({SW})) concentration. {F}urther, high-resolution {P}/{C}a records in multiple colonies of {P}avona gigantea and {P}orites lobata corals grown at the same upwelling location in the {G}ulf of {P}anama were strongly correlated to a contemporaneous time-series record of surface water {PO}4 {SW} at this site (r(2) = 0.7-0.9). {T}his study supports application of the following multi-colony calibration equations to down-core records from comparable upwelling sites, resulting in +/- 0.2 and +/- 0.1 mu mol/kg uncertainties in {PO}4 ({SW}) reconstructions from {P}. lobata and {P}. gigantea, respectively. {P}/{C}a-{P}orites (lobata) (mu mol/mol) = (21.1 +/- 2.4){PO}4 {SW}(mu mol/kg) + (14.3 +/- 3.8) {P}/{C}a-{P}orites (lobata) (mu mol/mol) = (29.2 +/- 1.4){PO}4 {SW}(mu mol/kg) + (33.4 +/- 2.7) {I}nter-colony agreement in {P}/{C}a response to {PO}4 {SW} was good (+/- 5-12% about mean calibration slope), suggesting that species-specific calibration slopes can be applied to new coral {P}/{C}a records to reconstruct past changes in surface ocean phosphate. {H}owever, offsets in the v-intercepts of calibration regressions among co-located individuals and taxa suggest that biologically-regulated "vital effects" and/or skeletal extension rate may also affect skeletal {P} incorporation. {Q}uantification of the effect of skeletal extension rate on {P}/{C}a could lead to corrected calibration equations and improved inter-colony {P}/{C}a agreement. {N}evertheless, the efficacy of the {P}/{C}a proxy is thus supported by both broad scale correlation to mean surface water phosphate and regional calibration against documented local seawater phosphate variations.},
  keywords = {},
  booktitle = {},
  journal = {{G}eochimica et {C}osmochimica {A}cta},
  volume = {74},
  numero = {4},
  pages = {1282--1293},
  ISSN = {0016-7037},
  year = {2010},
  DOI = {10.1016/j.gca.2009.11.002},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049238},
}