We followed a series of criteria for quantifying nutricline depths and trends to improve the accuracy of our analyses. First, we only recorded the nutricline depth of a cast if there existed interpolated concentrations above and below said depth. Second, we binned the coordinates of each nutricline depth to the nearest degree of latitude and longitude to quantify average nutricline depths per unique coordinate and year. Lastly, we quantified trends only from average nutricline depths that were deeper than 50 m and at a latitude from 45°S to 45°N. We also repeated our analysis using a depth boundary of 25 m. We selected these boundaries to target trends in regions where nutrients limit growth, and minimize effects from seasonal changes in stratification (59).