Benthic respiration and nutrient fluxes are measured in sediment cores incubated in the dark and at in situ temperatures in the laboratory. Incubation duration iss determined by the time required for oxygen concentrations to fall by 2 to 5 mg O2 L-1 but remain above 50% of saturation (generally 6 to 48 hrs). Dissolved inorganic nitrogen and phosphorus are measured at at least 4 time points concurrent with O2 measurements. At the beginning and end of the incubation period, samplesare taken for total CO2 (TCO2 or DIC) analyses. Dissolved organic carbon (DOC), total dissolved nitrogen (TDN), N2O, and methane (CH4) were also measured during some fluxes.

Benthic respiration (based on O2, CO2 or CH4) and nutrient flux across the sediment-water interfaceare calculated as the slope of the constituent concentration versus time. By convention, positive values indicate efflux (constituent released from the benthos) and negative values indicate influx (constituent taken up by the benthos). Respiration values were corrected for changes in the water overlying the cores by subtracting constituent consumption measured in BOD bottles. Values are means of 2 to 4 cores, and standard errors (S.E.) represent the error of the mean.

NOTES AND COMMENTS:
As indicated above, the benthic flux dataset is a derived dataset. That is, the values presented may be several calculation steps away from the raw data. Potential users are advised to contact one of the principle investigators for details.

1. At Stations BEN-PR-P22 and BEN-PR-P14, some flux incubationswere run to look at the differences between fluxes during high versus low tides. These parallel fluxes began in October, 1999 for Station BEN_PR_P22 and in April 2001 for BEN_PR_P14 and were discontinued after September, 2004. Sediment cores were incubated with overlying water collected to represent high tide and low tide conditions at each site. In the data, the parallel fluxes are distinguished by the salinity value listed.

2. To look at the duration of a salinity effect on fluxes, cores from Station BEN_PR_P22 in May, 2000, were incubated twice, with the second incubation starting 5 days after the first. During the second incubation, only O2, TCO2, and NH4 fluxes were measured.

3. NA in data cell indicates data are not available.

4. TBA in data cell refers to "to be analyzed".

Site (Current Name) , Site (Previous Name)
BEN-PR-P22, BEN-PR-P2
BEN-PR-P22 (Intertidal), BEN-PR-P2 (Intertidal)
BEN-PR-P24.2, BEN-PR-P0
BEN-PR-P24 , BEN-PR-P1
BEN-PR-P14 , BEN-PR-P5
BEN-PR-P11 , BEN-PR-TL
BEN-RO-R5.5 , BEN-SO-Row
BEN-PR-P23.5 , BEN-PR-E0
BEN-PR-P23.5 (Intertidal), BEN-PR-E0 (Intertidal)
BEN-EG-E13, BEN-RO-R13
BEN-EG-E13.5, BEN-RO-R13.5
BEN-EG-E14, BEN-RO-R14