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PARAGON 1 - KM2112 - Particulate Carbon and Nitrogen Timecourse Incubations

This dataset contains measurements of particulate carbon and nitrogen concentrations collected during the PARAGON 1 expedition (KM2112) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Samples for measurements of particulate carbon and nitrogen concentrations were collected at multiple time points for each experimental biological replicate by filtering 4 L of seawater from polycarbonate incubation bottles onto pre-combusted 25 mm glass fiber filters (GF/F, Whatman) under positive pressure. Filters were then transferred to polystyrene Petri dishes lined with pre-combusted aluminum foil and stored at -20°C until analysis onshore. Filters were then analyzed by high temperature combustion using an Exeter CE-440 Elemental Analyzer according to Grabowski et al. (2019). Particulate carbon concentrations are measurements of total particulate carbon, including both organic and inorganic carbon. Timestamp is in UTC.

PARAGON 1 - KM2112 - Nitrogen Timecourse Incubations

This dataset contains measurements of nitrogen concentrations collected during the PARAGON 1 expedition (KM2112) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Samples for measurements of nitrogen concentrations were collected at multiple time points for each experimental biological replicate by subsampling 250 mL aliquots from polycarbonate incubation bottles into high density polyethylene bottles and freezing upright at -20°C until analysis onshore. Nitrate plus nitrite (NO₃⁻ + NO₂⁻) concentrations were measured colorimetrically using segmented flow on a SEAL Autoanalyzer III with a high resolution detector as described by Foreman et al. (2019). Total nitrogen concentrations were measured similarly, following overnight UV oxidation of the sample according to Foreman et al. (2019). NO₂⁻ concentrations were measured using the high sensitivity chemiluminescent method described by Dore and Karl (1996) and Foreman et al. (2016). Ammonium (NH₄⁺) concentrations were determined using the high sensitivity fluorometric method of Holmes et al. (1999). For each analysis, reported values are the average of technical duplicate measurements from each sample. Timestamp is in UTC. Version 2 corrects formatting errors in the timestamp.

PARAGON 1 - KM2112 - Iron Uptake Timecourse Incubations

This dataset contains measurements of rates of dissolved iron (Fe) uptake collected during the PARAGON 1 expedition (KM2112) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Rates of iron uptake were measured at multiple time points for each experimental biological replicate by subsampling 250 mL aliquots from polycarbonate incubation bottles into new polycarbonate bottles and spiking with a final concentration of 0.4 nmol L⁻¹ ⁵⁵FeCl₃ with a specific activity of 2.74 Ci mmol⁻¹ of Fe (Perkin Elmer). A killed blank measurement was made for each experimental treatment by spiking an additional 250 mL aliquot with a final concentration of 1% glutaraldehyde prior to spiking with ⁵⁵FeCl₃. All aliquots were then incubated in the dark at in situ temperature for 8-10 hours. Incubations were terminated by filtering the entire 250 mL aliquot for each sample through a 0.2 µm polycarbonate filter. In order to remove extracellularly bound Fe, filters were rinsed 3 times with an oxalate wash according to Tang and Morel (2006) followed by three rinses with 0.2 µm filtered seawater. Filters were then transferred to high density polyethylene scintillation vials and submerged in 10 mL of Ultima Gold LLT scintillation cocktail (Perkin Elmer). Radioactivity incorporated into microbial biomass was measured on a TriCarb 4910TR scintillation counter. Values reported are blank-corrected but have not been adjusted for isotope dilution resulting from unlabeled iron present in situ. Timestamp is in UTC. Version 2 corrects formatting errors in the timestamp.

PARAGON 1 - KM2112 - Total Organic Carbon Timecourse Incubations

This dataset contains measurements of total organic carbon concentrations (TOC) collected during the PARAGON 1 expedition (KM2112) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Samples for measurements of TOC concentrations were collected at multiple time points for each experimental biological replicate by aliquoting 40 mL of whole seawater from polycarbonate incubation bottles into pre-combusted borosilicate vials. Samples were acidified with 27 µL of 12N HCl (Optima grade, Fisher), capped with Teflon-lined silicone septa lids, and stored in the dark at room temperature until analysis on shore. Total organic carbon concentrations were determined by high temperature combustion on a modified Shimadzu TOC analyzer according to Carlson et al. (2010). Timestamp is in UTC. Version 2 corrects formatting errors in the timestamp.

PARAGON 1 - KM2112 - Leucine Incorporation Timecourse Incubations

This dataset contains measurements of rates of leucine incorporation as a measure of bacterial production collected during the PARAGON 1 expedition (KM2112) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Rates of leucine incorporation were measured at multiple time points for each experimental biological replicate by subsampling 1.5 mL aliquots from polycarbonate incubation bottles into 2 mL microcentrifuge tubes (Axygen) and spiking with a final concentration of 20 nmol L⁻¹ leucine with a ³H specific activity of 53.3 Ci mmol⁻¹ of leucine (Perkin Elmer). A killed blank measurement was made for each experimental biological replicate by spiking an additional 1.5 mL aliquot with 100 µL of 100% (w/v) ice-cold trichloroacetic acid (TCA) prior to spiking with ³H-leucine. All aliquots were then incubated in the dark at in situ temperature for 4-6 hours after which live incubations were terminated with the addition of 100 µL of 100% (w/v) ice-cold TCA. Samples were processed at sea using the centrifugation method of Smith and Azam (1992), and radioactivity incorporated into bacterial protein was measured on a TriCarb 4910TR scintillation counter using Ultima Gold LLT scintillation cocktail (Perkin Elmer). Values reported are the blank-corrected averages of triplicate measurements from each sample. Timestamp is in UTC. Version 2 corrects formatting errors in the timestamp.

PARAGON 2 - KM2209 - Nitrogen Timecourse Incubations

This dataset contains measurements of nitrogen concentrations collected during the PARAGON 2 expedition (KM2209) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Samples for measurements of nitrogen concentrations were collected at multiple time points for each experimental biological replicate by subsampling 250 mL aliquots from polycarbonate incubation bottles into high density polyethylene bottles and freezing upright at -20°C until analysis onshore. Nitrate plus nitrite (NO₃⁻ + NO₂⁻) concentrations were measured colorimetrically using segmented flow on a SEAL Autoanalyzer III with a high resolution detector as described by Foreman et al. (2019). Total nitrogen concentrations were measured similarly, following overnight UV oxidation of the sample according to Foreman et al. (2019). NO₂⁻ concentrations were measured using the high sensitivity chemiluminescent method described by Dore and Karl (1996) and Foreman et al. (2016). Ammonium (NH₄⁺) concentrations were determined using the high sensitivity fluorometric method of Holmes et al. (1999). For each analysis, reported values are the average of technical duplicate measurements from each sample. Timestamp is in UTC.

PARAGON 2 - KM2209 - Iron Uptake Timecourse Incubations

This dataset contains measurements of rates of dissolved iron (Fe) uptake collected during the PARAGON 2 expedition (KM2209) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Rates of iron uptake were measured at multiple time points for each experimental biological replicate by subsampling 250 mL aliquots from polycarbonate incubation bottles into new polycarbonate bottles and spiking with a final concentration of 0.4 nmol L⁻¹ ⁵⁵FeCl₃ with a specific activity of 2.74 Ci mmol⁻¹ of Fe (Perkin Elmer). A killed blank measurement was made for each experimental treatment by spiking an additional 250 mL aliquot with a final concentration of 1% glutaraldehyde prior to spiking with ⁵⁵FeCl₃. All aliquots were then incubated in the dark at in situ temperature for 8-10 hours. Incubations were terminated by filtering the entire 250 mL aliquot for each sample through a 0.2 µm polycarbonate filter. In order to remove extracellularly bound Fe, filters were rinsed 3 times with an oxalate wash according to Tang and Morel (2006) followed by three rinses with 0.2 µm filtered seawater. Filters were then transferred to high density polyethylene scintillation vials and submerged in 10 mL of Ultima Gold LLT scintillation cocktail (Perkin Elmer). Radioactivity incorporated into microbial biomass was measured on a TriCarb 4910TR scintillation counter. Values reported are blank-corrected but have not been adjusted for isotope dilution resulting from unlabeled iron present in situ. Timestamp is in UTC.

PARAGON 2 - KM2209 - Particulate Carbon and Nitrogen Timecourse Incubations

This dataset contains measurements of particulate carbon and nitrogen concentrations collected during the PARAGON 2 expedition (KM2209) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Samples for measurements of particulate carbon and nitrogen concentrations were collected at multiple time points for each experimental biological replicate by filtering 4 L of seawater from polycarbonate incubation bottles onto pre-combusted 25 mm glass fiber filters (GF/F, Whatman) under positive pressure. Filters were then transferred to polystyrene Petri dishes lined with pre-combusted aluminum foil and stored at -20°C until analysis onshore. Filters were then analyzed by high temperature combustion using an Exeter CE-440 Elemental Analyzer according to Grabowski et al. (2019). Particulate carbon concentrations are measurements of total particulate carbon, including both organic and inorganic carbon. Timestamp is in UTC.

PARAGON 2 - KM2209 - Total Organic Carbon Timecourse Incubations

This dataset contains measurements of total organic carbon concentrations (TOC) collected during the PARAGON 2 expedition (KM2209) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Samples for measurements of TOC concentrations were collected at multiple time points for each experimental biological replicate by aliquoting 40 mL of whole seawater from polycarbonate incubation bottles into pre-combusted borosilicate vials. Samples were acidified with 27 µL of 12N HCl (Optima grade, Fisher), capped with Teflon-lined silicone septa lids, and stored in the dark at room temperature until analysis on shore. Total organic carbon concentrations were determined by high temperature combustion on a modified Shimadzu TOC analyzer according to Carlson et al. (2010). Timestamp is in UTC.

PARAGON 2 - KM2209 - Leucine Incorporation Timecourse Incubations

This dataset contains measurements of rates of leucine incorporation as a measure of bacterial production collected during the PARAGON 2 expedition (KM2209) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Rates of leucine incorporation were measured at multiple time points for each experimental biological replicate by subsampling 1 mL aliquots from polycarbonate incubation bottles into 2 mL microcentrifuge tubes (Axygen) and spiking with a final concentration of 20 nmol L⁻¹ leucine with a ³H specific activity of 53.3 Ci mmol⁻¹ of leucine (Perkin Elmer). A killed blank measurement was made for each experimental biological replicate by spiking an additional 1 mL aliquot with 100 µL of 100% (w/v) ice-cold trichloroacetic acid (TCA) prior to spiking with ³H-leucine. All aliquots were then incubated in the dark at in situ temperature for 4-6 hours after which live incubations were terminated with the addition of 100 µL of 100% (w/v) ice-cold TCA. Samples were processed at sea using the centrifugation method of Smith and Azam (1992), and radioactivity incorporated into bacterial protein was measured on a TriCarb 4910TR scintillation counter using Ultima Gold LLT scintillation cocktail (Perkin Elmer). Values reported are the blank-corrected averages of technical triplicate measurements from each sample. Timestamp is in UTC.