This readme.txt file was generated on 2024-12-20 by Bradly Evraets Recommended citation for the data: ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset Resazurin, resorufin, and chloride concentrations for input to resazurin processing rate calculations 2. Author Information Principal Investigator Contact Information Name: Bradly Evraets Institution: University of Minnesota Duluth Email: evrae003@d.umn.edu Associate or Co-investigator Contact Information Name: Karen Gran Institution: University of Minnesota Duluth Email: kgran@d.umn.edu 3. Date published or finalized for release: 2024 4. Date of data collection: Summer 2022 5. Geographic location of data collection: Chester Creek: 46.81981/-92.12327 Keene Creek: 46.76743/-92.17941 Miller Creek: 46.81991/-92.18122 Mission Creek: 46.67110/-92.27704 Sargent Creek: 46.68210/-92.27037 6. Information about funding sources that supported the collection of the data: Funding for the collection of these data was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR). 7. Overview of the data (abstract): Included in final_data.csv are data collected during field stream tracer experiments using the resazurin tracer system. The goal of the tracer experiments was to assess differences in hyporheic exchange and aerobic respiration between unrestored control reaches and realigned treatment reaches. This was done on Chester Creek, Keene Creek, Miller Creek, Mission Creek, and Sargent Creek in Duluth, Minnesota in the summer of 2022. This data file contains the pertinent raw and calculated data to generate breakthrough curves used to assess hyporheic exchange and aerobic respiration using the methods in Knapp et al. (2018). Data in nrri_chloride_conc.csv contains the ion chromatograph output information of chloride concentration with batch information, date of analysis, dilution factors, and sample notes. -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: These data are available with a Attribution 3.0 United States license (http://creativecommons.org/licenses/by/3.0/us/) 2. Links to publications that cite or use the data: N/A 3. Was data derived from another source? No If yes, list source(s): 4. Terms of Use: Data Repository for the U of Minnesota (DRUM) By using these files, users agree to the Terms of Use. https://conservancy.umn.edu/pages/policies/#drum-terms-of-use --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: final_data.csv Short description: Breakthrough curve data from tracer experiments conducted at the five creeks listed above in the summer 2022. B. Filename: nrri_chloride_conc.csv Short description: Ion chromatograph output information of chloride concentration with batch information, date of analysis, dilution factors, and sample notes. 2. Relationship between files: Chloride concentrations in final_data.csv column "Cl- (mg/L)" are from nrri_chloride_conc.csv but nrri_chloride_conc.csv contains information pertinent to understanding data quality. -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: Stream tracer experiments in summer 2022 involved mixing resazurin and sodium chloride in a bucket which was then injected into the streams as an instantaneous release a given distance above the study reaches. Stream water samples were collected at the top and bottom of each study reach using a syringe. Samples were then filtered in the field using a 0.45 µm multi-cellulose membrane filter held by a reusable syringe filter holder into polypropylene sample bottles and placed on ice in a cooler. The time and conductivity was noted for each sample. After returning from the field samples were split for resazurin and chloride concentration measurements. Samples for resazurin measurement were frozen until they were ready to be measured on a fluorescence spectrophotometer. Samples for chloride measurement were refrigerated until they were prepared for measurement. Chloride concentrations were measured on an ion chromatograph at the Natural Resources Research Institute (NRRI) for samples from all streams except Keene Creek. Samples from Keene Creek were measured using colorimetric methods by the Central Analytical Laboratory at NRRI. Preparation for samples for the ion chromatograph were diluted 5x, 12.5x, or 25x depending on expected chloride concentrations and then filtered through cation filters. Fluorescence of resazurin and resorufin were used to measure concentration but fluorescence of both compounds is pH dependent (Haggerty, et al., 2008). Fluorescence reaches a maximum above a pH of 8 so each sample was buffered with a 1:1 mixture of one molar NaOH and one molar NaH2PO4 · H2O. The buffer solution was added to stream and standard samples at 10:1 sample-to-buffer ratio by adding 0.1 mL of buffer and 1 mL of stream sample to each cuvette for measurement in a Cary Eclipse Fluorescence Spectrophotometer. Resazurin fluorescence intensity was measured using an excitation wavelength of 602 nm and an emission wavelength of 632 nm. Resorufin fluorescence intensity was measured using an excitation wavelength of 571 nm and an emission wavelength of 584 nm. 2. Methods for processing the data: Raz and Rru concentrations were calculated from fluorescence intensity using the MATLAB code in Knapp et al. (2018). Chloride concentration measurements from the ion chromatograph were correlated with field measured conductivity at each sample site to create a final chloride concentration for each sample. For more information see Appendix A in Evraets (2024). 3. Environmental/experimental conditions: Experiments were conducted during base flow conditions on all creeks except Keene Creek. Keene Creek may have been still above base flow due to spring runoff. 4. People involved with sample collection, processing, analysis and/or submission: David Baldus, Andy Kasun, Annika Erickson, Alexandra Thoresen, Steven Gilsdorf, Peter Book, Addison Knoll, Mary McMahon, Linnea Turner, Sarah Somerville helped with collection of field samples. Melissa Mauer-Jones provided access and training of the Cary Eclipse fluorescence spectrophotometer. Chan Lan Chun provided access to the ion chromatograph at NRRI and Matthew Berens and Chan Lan Chun's team helped with sample preparation. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Final_data.csv ---------------------------------------- 1. Number of variables: 18 2. Number of cases/rows: 628 3. Missing data codes: Code/symbol - Definition: Empty cells due to injection time row Code/symbol * Definition: Empty cells due to ion chromatograph malfunction and no collected chloride concentration or field conductivity was not recorded at sample collection. 4. Variable List A. Name: Site Description: Sample site name. B. Name: Sample Description: Sample name C. Name: Time Description: Time sample was collected in hh:mm:ss D. Name: Time Since Injection Description: Time after injection in hh:mm:ss E. Name: Time Since Inj (s) Description: Time after injection in seconds F. Name: Conductivity Description: Conductivity measured when sample was collected in uS/cm G. Name: Conductivity Change Description: Change in conductivity measured at sample collection relative to conductivity measured when ambient sample was collected. H. Name: Rru intense Description: Intensity as measured on the fluorescence spectrophotometer. I. Name: Raz intense Description: Intensity as measured on the fluorescence spectrophotometer. J. Name: Rru micromol/L Description: Concentration of Rru in micromol/L K. Name: Raz micromol/L Description: Concentration of Raz in micromol/L L. Name: Rru ppb Description: Concentration of Rru in parts per billion M. Name: Raz ppb Description: Concentration of Raz in parts per billion N. Name: Cl- (mg/L) Description: Chloride concentration in mg/L as measured on the ion chromatograph O. Name: Cl- from field Cond Description: Chloride concentration in mg/L from regression with conductivity. P. Name: dCl Cond (mg/L) Description: Change in chloride concentration in mg/L relative to Cl- from field Cond for ambient sample at each site. Q. Name: dCl Cond (umol/L) Description: dCl Cond converted to micromoles/Liter R. Name: Note Description: Important sample notes if necessary ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: nrri_chloride_conc.csv ----------------------------------------- 1. Number of variables:10 2. Number of cases/rows: 555 3. Missing data codes: Code/symbol - Definition: Data missing due to ion chromatograph malfunction. 4. Variable List A. Name: Sample ID Description: Sample number in the form of "stream abbreviation"-site number-sample number. Note that "CNC-", "CND-", and "CNT-" are chloride concentrations done for nutrient tracer experiments related to this project but not part of this thesis. CNC stands for Chester nutrient control reach, CND is Chester nutrient degraded control reach, and CNT is Chester nutrient treatment reach. Sample ID's that start with Deg are from the Chester Creek degraded control reach resazurin tracer experiments with Deg-1 being equivalent to site 5 and Deg-2 equivalent to site 6. B. Name: Stream Description: Stream name C. Name: Site Description: Site number D. Name: Sample Description: Sample number at each site. Amb is the ambient sample collected before tracer injection. E. Name: Dilution (x) Description: Dilution factor F. Name: IC Chloride (mg/L) Description: The chloride concentration measured by the ion chromatograph G. Name: Adj. Chloride (mg/L) Description: The chloride concentration calculated by multiplying the dilution factor by the IC Chloride measurement H. Name: Analysis Date Description: The date the sample was analyzed by the ion chromatograph I. Name: IC Batch File Description: The batch file name associated with each sample J. Name: Notes Description: Important notes if needed for each sample