Table 2. Field observations of inorganic nitrogen, N₂O and estimates of air-water fluxes in six pristine Australian mangrove creeks.

		NOx Concentration (μM)		NH4 concentration (μM)		N2O concentration (nM)		N2O saturation (%)		Average atmospheric N2O fluxa (μmol m−2 d−1)	Weighted atmospheric N2O fluxb (μmol m−2 d−1)	N2O mass balancec (μmol m−2 d−1)
Site	Latitude	Mean	Range	Mean	Range	Mean	Range	Mean	Range	Mean	Daily integrated	Daily integrated
Darwin	−12.45	0.59	<0.1–1.07	0.53	<0.1–0.79	6.3	6.0–6.8	98.9	94.7–104.3	−0.12 ± 0.01d>	−0.07d	−0.11
Hinchinbrook	−18.25	0.75	0.29–1.14	1.56	<0.1–5.93	6.1	5.6–6.9	83.3	75.4–90.5	−3.43 ± 0.06d	−3.26d	−3.20
Seventeen Seventy	−24.17	0.56	<0.1–1.07	0.75	0.29–1.86	7.7	7.1–8.9	94.3	87.6–106.2	−1.75 ± 0.11d	−0.48d	−0.35
Moreton Bay	−27.78	ND	ND	ND	ND	5.1	3.4–6.6	77.4	50.3–104.7	−3.19 ± 0.08d	−1.52d	−2.61
Newcastle	−32.85	0.11	<0.1–0.50	12.69	0.5–40.14	7.5	6.4–8.9	106.4	92.1–123.4	0.71 ± 0.03d	0.69d	0.03
Melbourne	−38.26	0.11	<0.1–0.42	25.50	<0.1–142.86	7.9	6.9–9.1	96.6	85.9–114.8	−1.33 ± 0.07d	−0.12d	−0.08
Average		0.42	<0.1–1.14	8.20	<0.1–142.86	6.8	3.4–9.1	92.9	50.3–123.4	−1.52 ± 0.17	−0.79 ± 0.57	−1.05 ± 0.59

^aPer m² water area, ±95% confidence interval ^bweighted for changes in water area and flux rates over the study period and normalised to total catchment area, ^ccalculated as a function of discharge and dissolved N₂O concentration integrated at 1 minute intervals, normalised to catchment area, ^dFlux rates determined using empirical transfer velocity equation of Ho et al.³³.