This dataset presents data of Nitrate plus nitrite δ15N (vs. AIR) and nitrate puls nitrite concentration measurements along a reef transect (2017 and 2023) on the reef flat of Surprise Island in the D'entrecasteaux Reefs, and also a reference site on the atoll rim. Nitrate isotope measurements have been performed using the denitrifier method (Weigand et al., 2016; doi:10.1002/rcm.7570) on seawater and groundwater samples from the CACAO expedition (2023; doi.org/10.17600/18002518) and TARA ENTRECASTEAUX 2017. The seawater along the reefflat and groundwater samples are exposed to seabird-derived nutrients (Choisnard et al. 2024, doi:10.1029/2024JC021004).
Further funding information: Max Planck Society (MPG) Paul Crutzen post-doctoral fellowship New Caledonia: IGUANE project (funded by the Labex Mer et Corail) GUANACO project (funded by LEFE and EC2CO)