TABLE 3.

Summary of measurement methods for environmental parameters

Measured parameter	Abbreviation	Unit	Method, instrument, or source for measurement	Reference(s)
Salinity		ppt	Measured in situ using water quality sonde
Temperature		°C	Measured in situ using water quality sonde
pH			Measured in situ using water quality sonde
Dissolved oxygen	DO	mg/liter	Measured in situ using water quality sonde
Turbidity		NTU	Measured in situ using water quality sonde
Total suspended solids	TSS	mg/liter	Dry mass captured by filtering 200 ml of sample water through 0.7-μm glass fiber filters	3
Extracted chlorophyll a		μg C/liter	Fluorometric measurement using acetone extract	94
Particulate organic carbon	POC	μg C/liter	Costech ECS 4010 analyzer	36
Particulate nitrogen	PN	μg N/liter	Costech ECS 4010 analyzer	36
Dissolved organic carbon	DOC	mg C/liter	Shimadzu TOC 5000-A	36
Dissolved inorganic carbon	DIC	mg C/liter	Shimadzu TOC 5000-A	95
Nitrate/nitrite	NO3/NO2	μg N/liter	Lachat QuikChem 8000 automated ion analyzer	36
Ammonium	NH4	μg N/liter	Lachat QuikChem 8000 automated ion analyzer	36
Dissolved organic nitrogen	DON	μg N/liter	Lachat QuikChem 8000 automated ion analyzer	34
Dissolved inorganic nitrogen	DIN	μg N/liter	Sum of NO3/NO2 and NH4	34
Total dissolved nitrogen	TDN	μg N/liter	Lachat QuikChem 8000 automated ion analyzer	34
Carbon-to-nitrogen molar ratio	C:N		Ratio of POC to PN	36
Phosphate	PO4	μg P/liter	Lachat QuikChem 8000 automated ion analyzer	34
Silicate	SiO4	μM	Lachat QuikChem 8000 automated ion analyzer	96
Primary productivity	PPR	mg C/m3/h	Light/dark [14C]bicarbonate incorporation	97, 98
River discharge		m/s	Daily avg from USGS gauging station 02089500 at Ft. Barnwell, 30 km upstream from the head of the NRE
Rainfall		cm	Daily sum from NWS station at New Bern, NC, airport
Daily avg wind speed		m/s	Daily avg from NWS station at New Bern, NC, airport
Phytoplankton photopigments		μg/liter	HPLCa	41

^aHPLC, high-pressure liquid chromatography.