Photic zone niche partitioning, stratification, and carbon cycling in the tropical Indian Ocean during the Piacenzian

Tangunan, Deborah N.; Hall, Ian R.; Beaufort, Luc; Berke, Melissa A.; Nederbragt, Alexandra; Bown, Paul R.

doi:10.5194/cp-21-2541-2025

Articles | Volume 21, issue 12

https://doi.org/10.5194/cp-21-2541-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/cp-21-2541-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 21, issue 12

Research article

|

05 Dec 2025

Research article |

| 05 Dec 2025

Photic zone niche partitioning, stratification, and carbon cycling in the tropical Indian Ocean during the Piacenzian

Deborah N. Tangunan, Ian R. Hall, Luc Beaufort, Melissa A. Berke, Alexandra Nederbragt, and Paul R. Bown

Supplement

https://doi.org/10.5194/cp-21-2541-2025-supplement

Data sets

Benthic foraminifera δ¹³C and δ¹⁸O records from IODP Site U1476 during the Piacenzian Deborah Tangunan et al. https://doi.org/10.5281/zenodo.16045490

Planktic foraminifera δ¹³C and δ¹⁸O records (G. ruber) from IODP Site U1476 during the Piacenzian Deborah Tangunan et al. https://doi.org/10.5281/zenodo.16045237

Coccolith δ¹³C and δ¹⁸O records from IODP Site U1476 during the Piacenzian Deborah Tangunan et al. https://doi.org/10.5281/zenodo.16044840

Coccolith mass data from IODP Site U1476 during the Piacenzian Deborah Tangunan et al. https://doi.org/10.5281/zenodo.16044410

Coccolith calcium carbonate at IODP Site U1476 during the Piacenzian Deborah Tangunan et al. https://doi.org/10.5281/zenodo.16043902

Relative abundances of coccolithophores at IODP Site U1476 during the Piacenzian Deborah Tangunan et al. https://doi.org/10.5281/zenodo.16043101

Short summary

We investigated sediments from the tropical Indian Ocean to study water column structure and carbon cycling during the mid-Piacenzian Warm Period, about 3 million years ago, when atmospheric carbon dioxide levels were similar to today. Our findings reveal persistent upper ocean stratification and niche separation among plankton groups, which limited nutrient mixing and carbon export to the deep ocean. These results highlight how ocean layering can influence climate feedback in a warmer world.