Impacts of Coral Growth on Geochemistry: Lessons From the Galápagos Islands

Coral skeletal architecture significantly impacts geochemical climate reconstructions, potentially introducing biases that alter paleoclimate interpretations. This study demonstrates that integrating coral density data with geochemistry can improve the accuracy of sea surface temperature (SST) reconstructions by up to 20%. Researchers analyzed paired geochemistry-density records from three Porites lobata corals at Wolf Island in the Galápagos, categorizing sampling transects based on skeletal architecture quality. They found that suboptimal transects, characterized by off-axis corallite orientation or changing growth direction, correlated with nonclimatic variations in trace elements like Sr/Ca, Ba/Ca, and Mg/Ca. By excluding these transects, the study achieved reconstructed SSTs closer to instrumental means while reducing reconstruction errors. These findings highlight the importance of skeletal architecture in refining coral-based paleoclimate records.

Reed, E. V., Thompson, D. M., Cole, J. E., Lough, J. M., Cantin, N. E., Cheung, A. H., Tudhope, A., Vetter, L., Jimenez, G., & Edwards, R. L. (2021). Impacts of Coral Growth on Geochemistry: Lessons From the Galápagos Islands. Paleoceanography and Paleoclimatology, 36(4). Portico. https://doi.org/10.1029/2020pa004051