Biomineral Formation in the Subtropical South Pacific: Insights From Major Ions and Carbonate Chemistry Along GEOTRACES Section GP21
Abstract
The South Pacific Ocean (SPO) hosts diverse biogeographical environments including the productive Peru‐Chile upwelling region and ultra‐oligotrophic subtropical gyre; however, vast areas are understudied regarding the cycling of dissolved calcium (Ca) and strontium (Sr), and distribution of major biomineral‐forming pelagic marine organisms. This study presents a high‐resolution basin‐scale analysis of dissolved Ca and Sr along the GEOTRACES GP21 transect to trace the production of calcium carbonate (CaCO 3 ) and celestine (SrSO 4 ). We used Optimum Multiparameter Analysis (OMPA) to correct for conservative water mass mixing, and quantify cumulative non‐conservative behavior of Ca and Sr along isopycnals to infer basin‐wide biomineral export production rates of CaCO 3 and SrSO 4 . Our findings revealed distinct, yet spatially variable rates of change in Ca and Sr associated with different balances between biomineral production and export driven by regional productivity gradients. In the upwelling region, biomineral export associated with high primary production was largely offset by strong biological recycling through higher grazing and shallow biomineral dissolution, reducing export efficiency. In contrast, lower grazing rates in the oligotrophic gyre led to a higher export rate. We highlighted the potential contribution of Acantharia to particulate organic carbon export production in the nutrient‐poor SPO oligotrophic gyre and underscored the need for their inclusion in global biogeochemical models. This work advances our understanding of pelagic CaCO 3 and SrSO 4 cycling and its implications for carbon production and sequestration in the sparsely sampled SPO.
Related
- Sedimentary characterization of the carbonate source rock of upper kimmeridgian parnac formation of the aquitaine basin (Quercy area)
- New Insights Into Nighttime Marine Sulfur and Nitrogen Chemistry and Related New Particle Formation Using the CLEPS Model
- Modulations of the Indian summer monsoon by the hot subtropical deserts: insights from coupled sensitivity experiments
- Diet and isotopic ecology of subantarctic fur seal at the subtropical Amsterdam Island
- Significant albedo-induced cooling effects across tropical and subtropical dryland biomes
BibTeX
@article{osullivan2026biomineral,
title = {{Biomineral Formation in the Subtropical South Pacific: Insights From Major Ions and Carbonate Chemistry Along GEOTRACES Section GP21}},
author = {Edel O'Sullivan and Kathleen Gosnell and Xue‐gang Chen and Louise Delaigue and Eric Achterberg and Te Liu and Juan Höfer and Zvi Steiner},
journal = {Global Biogeochemical Cycles},
year = {2026},
month = sep,
doi = {10.1029/2026gb009232},
url = {https://hal.science/hal-05758545v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Biomineral Formation in the Subtropical South Pacific: Insights From Major Ions and Carbonate Chemistry Along GEOTRACES Section GP21
AU - Edel O'Sullivan
AU - Kathleen Gosnell
AU - Xue‐gang Chen
AU - Louise Delaigue
AU - Eric Achterberg
AU - Te Liu
AU - Juan Höfer
AU - Zvi Steiner
PY - 2026
DA - 2026/09/22
JO - Global Biogeochemical Cycles
DO - 10.1029/2026gb009232
UR - https://hal.science/hal-05758545v1
AB - The South Pacific Ocean (SPO) hosts diverse biogeographical environments including the productive Peru‐Chile upwelling region and ultra‐oligotrophic subtropical gyre; however, vast areas are understudied regarding the cycling of dissolved calcium (Ca) and strontium (Sr), and distribution of major biomineral‐forming pelagic marine organisms. This study presents a high‐resolution basin‐scale analysis of dissolved Ca and Sr along the GEOTRACES GP21 transect to trace the production of calcium carbonate (CaCO 3 ) and celestine (SrSO 4 ). We used Optimum Multiparameter Analysis (OMPA) to correct for conservative water mass mixing, and quantify cumulative non‐conservative behavior of Ca and Sr along isopycnals to infer basin‐wide biomineral export production rates of CaCO 3 and SrSO 4 . Our findings revealed distinct, yet spatially variable rates of change in Ca and Sr associated with different balances between biomineral production and export driven by regional productivity gradients. In the upwelling region, biomineral export associated with high primary production was largely offset by strong biological recycling through higher grazing and shallow biomineral dissolution, reducing export efficiency. In contrast, lower grazing rates in the oligotrophic gyre led to a higher export rate. We highlighted the potential contribution of Acantharia to particulate organic carbon export production in the nutrient‐poor SPO oligotrophic gyre and underscored the need for their inclusion in global biogeochemical models. This work advances our understanding of pelagic CaCO 3 and SrSO 4 cycling and its implications for carbon production and sequestration in the sparsely sampled SPO.
SN - 0886-6236
SN - 1944-8224
ER -