Dataset: Benthic macroalgal carbon uptake rates

Parameter
Method

tidal_height
Exact tides at the time of the experiment were retrieved from https://tidesandcurrents.noaa.gov/noaatidepredictions.html?id=1612340

lat
Experimental locations were randomly chosen across a known gradient of submarine groundwater discharge (SGD). The waypoints (latitude and longitude) were inputted in a Garmin GSP 78. 

long
Experimental locations were randomly chosen across a known gradient of submarine groundwater discharge (SGD). The waypoints (latitude and longitude) were inputted in a Garmin GSP 78. 

incubation_time
Time started when benthic chamber was sealed into position and ended when benthic chamber was taken off the benthos.

temp_avg_inside
A HOBO tidbit temperature logger was placed inside the benthic chamber for the duration of the experiment. Temperature readings were taken every 5 minutes. This time series was averaged, resulting in this value.

sal_avg_inside
An Odyssey temperature and conductivity 

ph_amb
A water sample was taken from inside the benthic chamber at the beginning of the experiment (before 13C-sodium carbonate addition). pH was measured using a Thermo Scientific Orion Star A329 portable meter with a pH electrode calibrated against a Tris buffer of known pH from Andrew Dickson’s laboratory at the Scripps Institution of Oceanography.

phosphate_pre
A water sample was collected at the beginning of the experiment from inside the benthic chamber. This water were filtered through a 0.2um filter (GF/F) in situ, and refrigerated for 3 weeks. The samples were brought to room temperature, mixed, and analyzed on a Seal Analytical Segmented Flow Injection AutoAnalyzer AA3HR for soluble reactive phosphate (PO43-).

silicate_pre
A water sample was collected at the beginning of the experiment from inside the benthic chamber. This water were filtered through a 0.2um filter (GF/F) in situ, and refrigerated for 3 weeks. The samples were brought to room temperature, mixed, and analyzed on a Seal Analytical Segmented Flow Injection AutoAnalyzer AA3HR for silicate (SiO).

No3_NO2_pre
A water sample was collected at the beginning of the experiment from inside the benthic chamber. This water were filtered through a 0.2um filter (GF/F) in situ, and refrigerated for 3 weeks. The samples were brought to room temperature, mixed, and analyzed on a Seal Analytical Segmented Flow Injection AutoAnalyzer AA3HR for nitrate + nitrite (N + N; NO2- + NO3-).

ammonia_pre
A water sample was collected at the beginning of the experiment from inside the benthic chamber. This water were filtered through a 0.2um filter (GF/F) in situ, and refrigerated for 3 weeks. The samples were brought to room temperature, mixed, and analyzed on a Seal Analytical Segmented Flow Injection AutoAnalyzer AA3HR for ammonium (NH4+).

PAR_avg_outside
An autonomous Odyssey Submersible Photosynthetic Active Radiation Logger was deployed within the benthic chamber. The scan rate was one per minute and the detected wavelength was cosine corrected photosynthetic irradiance (400_700nm).

adv_mean
A Nortek Vector 3D Acoustic Velocimeter was deployed outside the chamber, within 40cm of the benthos. It was set to sample continuously at a sampling rate of 8 Hz, with a nominal velocity range of 0.30 m/s.

DIC_amb
Right before (within 5 minutes) the 13C sodium bicarbonate spike, water samples for DIC analysis (250 ml) were collected from within the benthic chamber and stored in 300 mL borosilicate bottles. Samples were brought back to the lab and fixed with 200 _l HgCl2 per 250 ml seawater. Samples were analyzed for DIC using the UIC Coulometer and Marianda VINDTA 3D at the S-LAB at the University of Hawai‘i at M_noa.

DIC_2
Right after (within 2 minutes) the 13C sodium bicarbonate spike, water samples for DIC analysis (250 ml) were collected from within the benthic chamber and stored in 300 mL borosilicate bottles. Samples were brought back to the lab and fixed with 200 _l HgCl2 per 250 ml seawater. Samples were analyzed for DIC using the UIC Coulometer and Marianda VINDTA 3D at the S-LAB at the University of Hawai‘i at M_noa.

DIC_postexp
At the end of the 1 hour incubation, water samples for DIC analysis (250 ml) were collected from within the benthic chamber and stored in 300 mL borosilicate bottles. Samples were brought back to the lab and fixed with 200 _l HgCl2 per 250 ml seawater. Samples were analyzed for DIC using the UIC Coulometer and Marianda VINDTA 3D at the S-LAB at the University of Hawai‘i at M_noa.

del_13C_DIC_amb
Right before (within 5 minutes) the 13C sodium bicarbonate spike, water samples were collected from within the benthic chamber and stored in 30 mL borosilicate bottles. Samples were brought back to the lab and fixed with 200 _l HgCl2 per 250 ml seawater. Water samples were sent to the Biogeochemical Stable Isotope Facility at the University of Hawai‘i at M_noa for _13C analysis of dissolved inorganic carbon (Torres et al. 2005).

del_13C_DIC_2
Right after (within 2 minutes) the 13C sodium bicarbonate spike, water samples were collected from within the benthic chamber and stored in 30 mL borosilicate bottles. Samples were brought back to the lab and fixed with 200 _l HgCl2 per 250 ml seawater. Water samples were sent to the Biogeochemical Stable Isotope Facility at the University of Hawai‘i at M_noa for _13C analysis of dissolved inorganic carbon (Torres et al. 2005).

del_13C_DIC_postexp
At the end of the 1 hour incubation, water samples were collected from within the benthic chamber and stored in 30 mL borosilicate bottles. Samples were brought back to the lab and fixed with 200 _l HgCl2 per 250 ml seawater. Water samples were sent to the Biogeochemical Stable Isotope Facility at the University of Hawai‘i at M_noa for _13C analysis of dissolved inorganic carbon (Torres et al. 2005).