depicted here are average values for all of 1972 -2022 at each unique geographic coordinate (gray dots; sites for ZNO3, 5 n = 8,508; sites for ZPO4, n = 9,033). The thresholds for defining these nutricline depths were 3 µmol kg -1 and 3/16 µmol kg -1 for nitrate and phosphate respectively. The dashed line is the contour of 50 m depth; we determined trends from nutriclines deeper than 50 m. (C) The difference of average nitracline and phosphacline depths (sites for ZNO3 -ZPO4, n = 8,284). These maps show values that were spatially interpolated using DIVA in Ocean Data View.