event  cast  cycle  date      event_lat  event_lon   depth  sample  nitrate     NO3_uptake  
894    57    4      07172010  8.58308    -90.18165   2      15-1    1.597655    0.530783    
894    57    4      07172010  8.58308    -90.18165   12     15-2    1.618619    0.130814    
894    57    4      07172010  8.58308    -90.18165   20     15-3    7.027533    0.062694    
894    57    4      07172010  8.58308    -90.18165   30     15-4    18.548121   0.096674    
894    57    4      07172010  8.58308    -90.18165   40     15-5    26.858866   0.048244    
894    57    4      07172010  8.58308    -90.18165   50     15-6    29.984136   0.063666    
894    57    4      07172010  8.58308    -90.18165   60     15-7    31.498496   0.058772    
894    57    4      07172010  8.58308    -90.18165   80     15-8    32.416235   0.064077