Table 1.

Summary of experimental conditions for the Lake Lugano and Namibian Upwelling experiments.

Location	Name	pH	[O2] μM	Tracers	Timepoints (hours)
Lake Lugano	control-pH, control-O2	7.54±0.02	290±14	1) 1 μM 15${\text{NH}}_4^{+}$ + 1 μM NA NO2− 2) 1 μM NA ${\text{NH}}_4^{+}$ + 1 μM 15NO2−	0, 5, 17, 30
Lake Lugano	control-pH, reduced-O2	7.54±0.02	70±10	1) 1 μM 15${\text{NH}}_4^{+}$ + 1 μM NA NO2− 2) 1 μM NA ${\text{NH}}_4^{+}$ + 1 μM 15NO2−	0, 5, 17, 30
Lake Lugano	Reduced-pH, control-O2	7.20±0.02	290±14	1) 1 μM 15${\text{NH}}_4^{+}$ + 1 μM NA NO2− 2) 1 μM NA ${\text{NH}}_4^{+}$ + 1 μM 15NO2−	0, 5, 17, 30
Lake Lugano	reduced-pH, reduced-O2	7.20±0.02	70±9	1) 1 μM 15${\text{NH}}_4^{+}$ + 1 μM NA NO2− 2) 1 μM NA ${\text{NH}}_4^{+}$ + 1 μM 15NO2−	0, 5, 17, 30
Namibian upwelling	control-O2	–	220±12	1) 1 μM 15${\text{NH}}_4^{+}$ + 1 μM NA NO2− 2) 1 μM NA ${\text{NH}}_4^{+}$ + 1 μM 15NO2−	0, 24
Namibian upwelling	reduced-O2	–	50±10	1) 1 μM 15${\text{NH}}_4^{+}$ + 1 μM NA NO2− 2) 1 μM NA ${\text{NH}}_4^{+}$ + 1 μM 15NO2−	0, 24
Namibian upwelling	reduced-O2	–	20±10	1) 1 μM 15${\text{NH}}_4^{+}$ + 1 μM NA NO2− 2) 1 μM NA ${\text{NH}}_4^{+}$ + 1 μM 15NO2−	0, 24