Use of ^𝟏𝟓N Natural Abundance and N Species Concentrations to Assess N-Cycling in Constructed and Natural Coastal Wetlands

Table 1

Nitrate and ammonium data for surface and pore water in Grave’s Dock (GD), Chechessee March (CM), Chechessee Creek Club retention pond (CP), and Oyster Rake (OR).

Site	Month	Depth (cm)	NO3-N (mg L^−1)	𝛿^15NO3− (‰)	NH4-N (mg L^−1)	𝛿^15NH4+ (‰)
GD	Jan	Surface Water	BDL	ND	0.05	3.3
		Sediment 0–10	BDL	ND	6.05	4.2
		Sediment 30–40	BDL	ND	13.16	3.3
	Apr	Surface Water	BDL	ND	0.06	ND
		Sediment 0–10	BDL	ND	2.36	2.3
		Sediment 30–40	BDL	ND	17.07	3.5
	Oct	Surface Water	BDL	ND	0.01	−4.7
		Sediment 0–10	BDL	ND	11.43	3.2
		Sediment 30–40	BDL	ND	15.70	3.3
CM	Jan	Surface Water	BDL	ND	0.42	5.9
		Sediment 0–10	BDL	ND	3.24	2.7
		Sediment 30–40	BDL	ND	9.00	2.7
	Apr	Surface Water	BDL	ND	BDL	ND
		Sediment 0–10	BDL	ND	1.67	5.8
		Sediment 30–40	BDL	ND	3.13	1.9
	Oct	Surface Water	BDL	ND	BDL	ND
		Sediment 0–10	BDL	ND	3.01	6.0
		Sediment 30–40	BDL	ND	4.88	4.4
CP	Jan	Surface Water	1.73	5.0	BDL	ND
	Apr	Surface Water	1.58	3.7	0.13	5.7
	Oct	Surface Water	0.33	−1.2	0.11	7.7
OR	Oct	Surface Water	4.60	3.7	0.08	ND
		Sediment 0–10	0.16	ND	3.67	4.9
		Sediment 20–30	0.18	ND	2.58	1.7
		Treated Wastewater	3.15	4.9	1.74	26.4