Schmidt, Sarina , Hathorne, Ed C. , Schönfeld, Joachim, Gosnell, Kathleen J. and Garbe‐Schönberg, Dieter (2024) Incorporation of Dissolved Heavy Metals Into the Skeleton of Porites Corals Based on Multi‐Element Culturing Experiments. Geochemistry, Geophysics, Geosystems, 25 (9). Art.Nr. e2022GC010726. DOI 10.1029/2022GC010726.

Preview	Text Geochem Geophys Geosyst - 2024 - Schmidt - Incorporation of Dissolved Heavy Metals Into the Skeleton of Porites Corals.pdf - Published Version Available under License Creative Commons: Attribution 4.0. Download (2MB) | Preview
	Text 2022gc010726-sup-0001-supporting information si-s01.docx - Supplemental Material Available under License Creative Commons: Attribution 4.0. Download (7MB)
	Other (Supplementary information) 2022gc010726-sup-0002-table si-s01.xlsx - Supplemental Material Available under License Creative Commons: Attribution 4.0. Download (68kB)
	Other (Supplementary information) 2022gc010726-sup-0003-table si-s02.xlsx - Supplemental Material Available under License Creative Commons: Attribution 4.0. Download (13kB)
	Other (Supplementary information) 2022gc010726-sup-0004-table si-s03.xlsx - Supplemental Material Available under License Creative Commons: Attribution 4.0. Download (15kB)

Abstract

Key Points

Porites corals grow normally with increased exposure to multiple metals over >1 year

Skeletal partitioning variable within and between colonies and with seawater metal content

Good agreement with previous work, especially for Pb across a large range of metal content

Anthropogenic activities increase the level of dissolved heavy metals in some tropical near‐shore environments threatening reef ecosystems. The skeleton of stony corals like Porites species potentially provides a high‐resolution geochemical archive for past heavy metal concentrations, with potentially century long records revealing baseline values before large‐scale human disturbance. However, few data exist for heavy metal partitioning into coral skeleton aragonite. To address this, culturing experiments exposing Porites lobata and Porites lichen to a mixture of dissolved Cr, Mn, Ni, Cu, Zn, Ag, Cd, Sn, Hg, and Pb over a wide concentration range have been performed. Water samples were taken frequently to monitor changes in the heavy metal concentration. Laser ablation ICP‐MS measurements of the coral aragonite revealed metal concentrations that were positively correlated with Cr, Mn, Ni, Zn, Ag, Cd, and Pb concentrations in seawater. The D TE values for most metals appear dependent on the seawater metal content, approximating a power law, and therefore stabilize at higher seawater metal/Ca ratios. The partitioning of Pb into the coral skeleton is a notable exception, with D Pb being stable around 2 to 1 across a large range of “natural” to highly polluted seawater Pb concentrations. This and the general agreement with partition coefficients estimated by previous work suggests that the reconstruction of the heavy metal concentration in seawater for ecosystem monitoring is possible. However, the high variability within and between coral colonies requires further study and suggests that multiple records from multiple coral colonies should be combined to obtain robust reconstructions.

Key Points

Porites corals grow normally with increased exposure to multiple metals over >1 year
Skeletal partitioning variable within and between colonies and with seawater metal content
Good agreement with previous work, especially for Pb across a large range of metal content

Actions (login required)

View Item