(Table S3) Sensitivity analysis for all nitrogen fixation rate (NFR) measurements in the South Indian Ocean and the French Southern and Antarctic Lands, Marion Dufresne cruise MD206

The contribution of each source of error to the total uncertainty is provided, as performed by Montoya et al. (1996) and Gradoville et al. (2017, doi:10.1002/lno.10542). The Average and SD are measured for triplicate incubation bottles (columns 20, 21, 25, 26, 30, 31,35, 36, 40, and 41). dNFR/ dX (columns 23, 28, 33, 38, and 43) represent the partial derivative of the NFR with respect to each parameter, calculated by the average and standard deviation. Error Contribution and % Total Error (columns 24, 25, 29, 30, 34, 35, 39, 40, 44, and 45) represent the absolute and relative error associated with each parameter. The total uncertainty associated with each measurement is termed the "Minimal Quantifiable Rate" (column 13) and calculated using standard propagation of error. An alternative limit of detection was performed by setting the change in atom percent 15N2 of PN equal to 0.00146 atom % (column 18).