BUSCADOR RECOLECTA

SAMIpH_Database_2012_2017.csv provides data for the years 2012 and 2017.DATE_UTC and TIME_UTC are the day and time at which the measurement was taken, in UTC. pHConstSal35 is the pH at a constant salinity of 35. TEMPERATURE and SALINITY are the water temperature (in degrees Celsius) and the water salinity (practical salinity units, i.e., no units) respectively. SAMICO2_Database_2013_2017.txt provides data between the years 2013 and 2017. DATE are the day and time at which the measurement was taken, in UTC and CO2 is the in situ pCO2 value (in uatm) recorded by the SAMI device, The database provides measurements of the carbon system parameters pH and pCO2 obtained with SAMI sensors (Sunburst Sensors, LLC) attached to a mooring line deployed in the Strait of Gibraltar between the years 2012 and 2017. Temperature and salinity data were obtained with a Conductivity-Temperature probe (CT Seabird SBE37-SMP) also installed in the line. Sampling interval was initially set to 60 min, but a battery run off happened in summer 2013 (which caused a six-month data gap) advised changing the interval to 120min to extend the battery life., This research was supported by the COMFORT project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 820989 (project COMFORT, "Our common future ocean in the Earth system – quantifying coupled cycles of carbon, oxygen, and nutrients for determining and achieving safe operating spaces with respect to tipping points).” Funding was also provided by grant EQC2018-004285-P funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”., Peer reviewed

2 pages. -- Supplementary Figure 1. Growth curve of cultured Symbiodiniaceae isolated from Cotylorhiza tuberculata. -- Supplementary Figure 2. Scanning electron microscopy (SEM) coupled with EDS (Energy Dispersive X-Rays spectroscopy) for chemical characterization of the calcifying matrix found in Symbiodiniaceae cultures. -- Supplementary Figure 3. Symbiodiniaceae living inside the jellyfish Cotylorhiza tuberculata in their typical coccoid stage in hospite., The photosymbiosis with host-specific dinoflagellates is a widespread relationship in marine organisms. Despite the evidenced biodiversity of this kind of mutualism, most research focuses on the study of scleractinian corals, and there is a lack of knowledge about other symbiotic cnidarians such as jellyfishes. The Mediterranean jellyfish Cotylorhiza tuberculata (Rhizostomae, Scyphozoa) harbors an endosymbiotic dinoflagellate of the family Symbiodiniaceae. In this study, we examine the algae distribution within the host body as well as, the pigment content and cell density of the symbiont. Furthermore, the size, morphology and fluorescence of cultured symbionts were studied under light microscopy, Imaging Flow Cytometry (IFC), and Scanning Electron Microscopy (SEM). The C:N composition and optical properties of the medusa tissue were measured to evaluate their role in the symbiosis. The medusae body was divided into two different sections to investigate the distribution of symbionts in hospite: oral arms (OA) and umbrella (UM). C:N composition of C. tuberculata was and symbiont density was significantly higher in the OA section. Mean chlorophyll a concentration of the algae was 1.33 (± 0.83) pg Chl a cell–1. The study of the pigment composition by HPLC (High Performance Liquid Chromatography), revealed the presence of 13 different pigments, being the most representative chlorophyll a, chlorophyll c2, and peridinin typical pigments of Symbiodiniaceae. Cell diameter of algae freshly isolated from the host was 8.71 ± 0.97 μm and cell growth rate was 0.52 (± 0.09) 106 cell ml–1 d–1. The presence of vegetative coccoid cells, doublet and motile mastigotes were revealed within the Symbiodiniaceae cultures. A calcifying matrix typical of Symbiodiniaceae and formed in partner with bacteria, was also observed most cultures. The umbrella tissue of the medusa absorbed at ultraviolet radiation (UVR) region, suggesting that medusae tissue protects photosymbionts from the negative effect of the high energetic UVR and attenuates the light intensity reaching algae inside the host. The presence of a dense Symbiodiniaceae population and the protection to UVR and elevated environmental irradiance provided by medusae tissue, maintain symbionts in optimal light conditions for photosynthesis and may be a reason added to explain the population success of Cotylorhiza tuberculata., Peer reviewed

[Description of methods used for collection/generation of data] The database provides discrete measurements of carbon system parameters in water samples collected at 13 stations during 5 campaigns conducted over 2020–2021. Geographic coordinates of sampling stations are provided. Some physical data (i.e. pressure, temperature and salinity) are also included. During the campaigns, temperature, salinity, conductivity, dissolved oxygen and pH were obtained with an EXO TM 2 multiparametric probe sonde. Surface seawater was subsequently collected for biogeochemical analysis. The biogeochemical variables shown in the database are pH in SWS and NBS scale (pH_SWS and pH_NBS), total alkalinity (AT), and inorganic nutrients (nitrite, nitrate, ammonium, silicate and phosphate), Dissolved Organic Carbon (DOC), Suspended Solid Matter (SSM), and chlorophyll a (Chla). · pH_NBS data were obtained by the EXO TM 2 multiparametric probe sonde and pH_SWS was measured with a Metrohm pH meter (model 780) at SWS scale that was calibrated according to DelValls & Dickson, (1998). · Samples for AT analysis were collected in 500-ml borosilicate bottles, and poisoned with 200 μl of HgCl2-saturated aqueous solution and stored until measurement in the laboratory. AT was measured by potential titration according to Mintrop et al. (2000) with a Titroprocessor (model Metrohm 794 for 2020 and model Metrothm 888 for 2021). · Water samples (5 mL, two replicates) for inorganic nutrients determination were taken, filtered immediately (Whatman GF/F, 0.7 μm) and stored frozen for later analyses in the shore-based laboratory. Nutrients concentrations were measured with a continuous flow auto-analyzer using standard colorimetric techniques (Hansen & Koroleff 1999). · Water samples for DOC and total dissolved nitrogen (TDN) determination were taken, filtered immediately (Whatman GF/F, 0.7 μm) and 100 μl of orthophosphoric acid (3:1) was added. Stored in fridge for later analyses in the laboratory. DOC and TDN concentrations were obtained by catalytic oxidation at high temperature (720°C) and chemiluminescence, respectively, applying the protocol described by Alvarez-Salgado & Miller, (1998). · SSM and the organic (particulate organic matter (POM) and inorganic (particulate inorganic matter (PIM)) fractions were determined by the loss on ignition method, filtering the water through pre-weighed Whatman 0.7 μm GF/F glass fibre filters pre-combusted at 450°C, with subsequent filter desiccation for 48 h and finally combustion. · Chla concentration was obtained by filtering water through Whatman 0.7 μm GF/F glass fibre filters that were maintained frozen and in the dark until analysis. The extract was measured by fluorometry following the method of Welschmeyer (1994)., This work was supported by the European Commission, [Fondo Europeo de Desarrollo Regional (FEDER)] through the project Apoio à gestão das zonas húmidas do litoral do Sudoeste Ibérico: interações entre Aquacultura e meio Ambiente na região transfronteiriça Alentejo-Algarve-Andaluzia 2 (AQUA&AMBI2) [ref: 0750_AQUA_AMBI_2_5_P]. SAV and AR were supported by a pre-doctoral grant from the Spanish Ministry of Science, Innovation and Universities [FPU19/04338 and FPU19/04557]. This work is a contribution to the CSIC Interdisciplinary Thematic Platform OCEANS+., Peer reviewed

This data set includes measurements of water samples collected from 11 water bodies (n = 6 to 12 per water body) between March 2010 and March 2011 within Doñana Natural Area. Geographic coordinates of sampling positions and a Google Earth .kml file are provided. Approximately every 30 days in situ water conductivity (converted to salinity), temperature and pH were measured using a multi-probe (YSI-6920V2, YSI Incorporated, Yellow Springs, Ohio, USA) and filtered water samples were collected for laboratory analysis of dissolved phosphate, silica (using a Skalar San++ 215 Continuous Flow Analyser) and total alkalinity (using a Metrohm 794 Titroprocessor following the method described by Mintrop et al. 2000). Dissolved carbon dioxide partial pressure was calculated from pH and total alkalinity using co2sys.xls (Pierrot et al., 2000) with the dissociation constants for carbon and sulphate of (Cai and Wang 1998) and (Dickson 1990), respectively. Carbon dioxide partial pressure in air and daily-ensemble-averaged horizontal wind velocity at 10 m above the land surface were provided by the ICTS Doñana Scientific Reserve (ICTS-2009-39) and are included to allow calculations of air-water fluxes. Estimates of the areal extent of the water bodies derived via remote sensing (DEIMOS-1 and Landsat 5 TM sensors) within each wetland region of Doñana Natural Area are included to allow up-scaling of fluxes to regional air-water carbon transport rates. A Google Earth .kml file delineating the wetland regions is provided and a Google Earth .kmz file showing an indication of the aggregate water coverage derived from the DEIMOS-1 sensor (8 images between Aug 2010 and Sept. 2011) is included to allow qualitative visualization of the areal extent and duration of water coverage. The data is provided as [space] delimited plain text files and Google Earth kml and kmz files within a compressed folder that also includes a detailed data description text file (README_data_description) written using "Simple Markdown" syntax converted to PDF and HTML., This dataset is subject to a Creative Commons License Attribution-Noncommercial-ShareAlike 3.0 Unported. If you use the data, please cite the publication., This data set includes recently published data used to calculate air-water carbon dioxide fluxes within aquatic areas of Doñana Natural Area, SW Spain (Long: -6.373, Lat: 36.932, Datum:WSG84) between March 2010 and 2011., This research was supported by projects P09–RNM–4744 and 049/2010 funded by the Regional Government of Andalucia and the Spanish Ministry for Agriculture, Food and Environment, respectively. Further analytical details, acknowledgements, air-water fluxes and transport rates can be found in the publication., Peer reviewed

This dataset gathers discrete measurements of CO2 (pH and alkalinity) and hydrographic variables (salinity, temperature, dissolved oxygen, nitrate, phosphate and silicate) in 10 cruises between 2005 and 2007 in the GIFT Time Series Stations located at the Strait of Gibraltar, pH was measured spectrophotometrically following the Clayton and Byrne (1993). This method consists on adding a dye solution to the seawater sample, so that the ratio between two absorbances at two different wavelengths is proportional to the sample pH. Alkalinity was measured using an automatic potentiometric titrator Titrando 794 Metrohm, with a Metrohm 6.0232.100 combination glass electrode and a Pt-1000 probe for temperature measurement following the methodology given by Pérez and Fraga (1987). Dissolved oxygen was analyzed following the widely applied Winkler method. Determinations of nitrate, phosphate and silicate were carried out following methods described by Hansen and Grassoff (1983) Salinity and Temperature were recorded with a CTD probe, The item is made of 11 files, of which 1 is the dataset and the other 10 files include detailed descriptions of the data per month of gathering, Dataset contributed to the project Carbochange, CARBOOCEAN, Data are part of the EC-funded Integrated Project CARBOOCEAN - Marine carbon sources and sinks assessment Contract no. 511176 (GOCE), more details available at http://www.carboocean.org/, No

The item is made of 2 files, of which 1 is the dataset and the other includes a small description of the measured variables.-- Dataset contributed to the Project Carbochange, This dataset gathers discrete measurements of CO2 (pH and alkalinity) and hydrographic variables (salinity, temperature, dissolved oxygen, nitrate, phosphate and silicate) obtained during the cruise P3A22008. carried out in the Strait of Gibraltar from 6 to 12 October 2008, pH was measured spectrophotometrically following the Clayton and Byrne (1993). This method consists on adding a dye solution to the seawater sample, so that the ratio between two absorbances at two different wavelengths is proportional to the sample pH. Alkalinity was measured using an automatic potentiometric titrator Titrando 794 Metrohm, with a Metrohm 6.0232.100 combination glass electrode and a Pt-1000 probe for temperature measurement following the methodology given by Pérez and Fraga (1987). Dissolved oxygen was analyzed following the widely applied Winkler method. Determinations of nitrate, phosphate and silicate were carried out following methods described by Hansen and Grassoff (1983) Salinity and Temperature were recorded with a CTD probe, Proyecto CARBOOCEAN (511176GOCE), y proyectos del Ministerio de Ciencia e Innovación (CTM2005/01091-MAR y CTM2008-05680-C02-01), No

This data set includes measurements of water samples collected from 11 water bodies (n = 8 to 30 per water body) between March 2010 and March 2013 within Doñana Natural Area. Geographic coordinates of sampling positions and a Google Earth .kml file are provided., Approximately every 30 days in situ water conductivity (converted to salinity), temperature and pH were measured using a multi-probe (YSI-6920V2, YSI Incorporated, Yellow Springs, Ohio, USA) and filtered water samples were collected for laboratory analysis of dissolved phosphate, silica (using a Skalar San^++ 215 Continuous Flow Analyzer) and total alkalinity (using a Metrohm 794 Titroprocessor following the method described by Mintrop et al. (2000) (http://hdl.handle.net/10261/25136). Dissolved carbon dioxide partial pressure was calculated from pH and total alkalinity using co2sys.xls (Pierrot et al., 2000) (http://cdiac.ornl.gov/ftp/co2sys/CO2SYS_calc_XLS_v2.1/) with the dissociation constants for carbon and sulphate of (Cai and Wang 1998) and (Dickson 1990) (https://doi.org/10.1016/0021-9614(90)90074-Z), respectively., Atmospheric partial pressure of CO2 (μatm) was obtained from the NOAA (National Oceanic and Atmospheric Administration, USA) monitoring station in Izaña, Spain (Site: IZO, http://www.esrl.noaa.gov/gmd/dv/site/)., Daily measurements of rainfall (mm), air temperature (ºC) and wind speed (m s-1) were provided by a meteorological station located in Lebrija (36º 58’ 35’‘N, 06º 07’ 34’’ W) maintained by the Junta de Andalucia (www.juntadeandalucia.es/agriculturaypesca/ifapa/ria/servlet/FrontController)., Estimates of the areal extent of the water bodies derived via remote sensing (Landsat image archive, (http://landsat.usgs.gov/) within each wetland region of Donana Natural Area are included to allow up-scaling of fluxes to regional air-water C transport rates. A Google Earth .kml file delineating the wetland regions is provided., The data is provided as [space] delimitated plain text files and Google Earth .kml and .kmz files within a compressed folder that also includes a single README file (in markdown format converted to HTML and PDF) containing a detailed description of the data structure., This dataset is subject to a Creative Commons License Attribution-ShareAlike 4.0 International., This data set includes recently published data used to calculate air-water carbon dioxide fluxes within aquatic areas of Doñana Natural Area, SW Spain (Long: -6.373, Lat: 36.932, Datum: WSG84) between March 2010 and May 2013., This research was supported by projects P09–RNM–4744 (Regional Government of Andalucia), 049/2010 and 1539/2015 (Spanish Ministry for Agriculture, Food and Environment)., Peer reviewed

This data set includes measurements of water samples collected from 5 sites during 8 surveys carried out between March 2016 and March 2017 in the Guadalquivir river estuary. Geographic coordinates of sampling positions and a Google Earth .kml file are provided. During samplings, in situ water conductivity (converted to salinity), temperature and pH were measured using a multi‐probe (YSI‐6920V2, YSI Incorporated, Yellow Springs, Ohio, USA) and water samples were collected for laboratory analysis of dissolved methane and nitrous oxide by static‐head space equilibration gas chromatography (GC) using an Agilent 7890 GC equipped with an Electron Capture Detector (ECD) for N2O and Flame Ionization Detector (FID) for CH4, according to de la Paz et al. (2015). Samples were also taken for analysis of phosphate, nitrate, nitrite and ammonia (with a Skalar Sanˆ++215 Continuous Flow Analyzer and using the standard colorimetric techniques described in Hansen and Koroleff 1999), dissolved oxygen and total alkalinity (using a Metrohm 794 Titroprocessor following the methods described by Mintrop et al. (2000) and Winkler) and dissolved organic carbon and total dissolved nitrogen that through catalytic oxidation at high temperature (720 °C) and chemiluminescence (using a Shimadzu Total Organic Carbon analyzer Model TOC‐VCPH/CPN, according to Álvarez‐Salgado and Miller 1998). Dissolved carbon dioxide partial pressure was calculated from pH and total alkalinity using co2sys.xls (Pierrot et al., 2000) with the dissociation constants for carbon and sulphate of Cai and Wang (1998) and Dickson (1990), respectively. Calculations of the equilibrium concentrations of methane and nitrous oxide in the water phase was done using the annual averaged atmospheric mixing ratios CH4 (xCH4atm) and N2O (xN2Oatm) provided by the World Data Center for Greenhouse Gases (http://ds.data.jma.go.jp/gmd/wdcgg/). Such mean values during the sampling period were calculated as 1866 ppb and 328 ppb for xCH4atm and xN2Oatm respectively. Daily measurements of rainfall (mm), air temperature (ºC), relative humidity and wind speed (m s‐1) were provided by ameteorological station located in Lebrija (36º 58’ 35’‘N, 06º 07’ 34”W) managed by the Junta de Andalucia (www.juntadeandalucia.es/agriculturaypesca/ifapa/ria/servlet/FrontController). The data are provided as [space] delimitated plain text files and Google Earth .kml and .kmz files within a compressed folder that also includes a single README file (in PDF format) containing a detailed description of the data structure., General Notes: The data are provided under an Attribution‐ShareAlike 4.0 International license. However, if you use the data, so as to support the authors, please consider citing the article: Emma Huertas, Susana Flecha, Gabriel Navarro, Fiz F. Perez, Mercedes de la Paz. 2018. Spatio‐temporal variability and controlling parameters of methane and nitrous oxide in the Guadalquivir Estuary, Southwestern Europe. Aquatic Sciences.-- Data collection and analytical techniques are given in detail with the associated publication, here we only give a brief details and a guide to the contents of the data files.-- Data files are in plain text format with [space] used as the delimiter and text enclosed in "". All data files have column titles as the first line. NA is used to represent no data., Geographical coordinates of water sampling sites: Guadalquivir_estuary_sampling_stations_geo_coordinates.txt provides the geographical coordinates of the sites. ST.ID represents the code (used to link to other data tables) for each site. long and lat are longitude and latitude, respectively. Geographic projection and WSG84 datum is used (EPSG:4326).-- For convenience Guadalquivir_estuary_sampling_stations.kml is also included to allow visualization of the site positions in Google Earth (or other GIS software; note kml files have the Pseudo‐Mercator projection [EPSG:3857])., Water physiochemical properties; Guadalquivir_estuary_water_monitoring_2016‐2017.txt provides data from water sampling data during eight surveys conducted between March 2016 and March 2017. Temperature, salinity and pH were measured with a multi‐probe (YSI‐6920V2, YSI Incorporated, Yellow Springs, Ohio, USA). Total alkalinity, concentrations of dissolved compounds (oxygen, organic carbon, total nitrogen, inorganic nitrogen and phosphate), pigments and suspended solids were measured in the laboratory. pCO2 was calculated using pH and total alkalinity with co2sys.xls.-- SAMP.EVENT is a convenience code used to denominate each individual survey. SAMP.DATE is the day in which the survey took place (in the Gregorian calendar). time.stamp.gmt is the time (GMT or UTC) at which the sample was collected, in extended ISO8601 format.-- ST.ID represents the code (used to link to other data tables) for each site. T.degC is the water temperature in degrees Celsius. Salinity is the water salinity (practical salinity units, i.e., no units), calculated from conductivity.-- CH4.nmolL is methane concentration with units nano mol per liter. N2O.nmolL is nitrous oxide concentration with units nano mol per liter.-- Chla.umolL is chlorophyll‐a concentration with units micro mol per liter. TSM.mgL is total suspended solids concentration with units milli gram per liter. DOC.mgL is total dissolved organic carbon concentration with units milli gram per liter. TDN.mgL is total dissolved nitrogen concentration with units milli gram per liter. NH4.umolL is dissolved ammonium concentration with units micro mol per liter. NO2.umolL is dissolved nitrite concentration with units micro mol per liter. NO3.umolL is dissolved nitrate concentration with units micro mol per liter. PO4.umolL is dissolved inorganic phosphate concentration (i.e., not organic or total) with units micro mol per liter. O2.umolKg is dissolved oxygen concentration with units micro mol per kilogram. pCO2.uatm is partial pressure of CO2 in water with units micro atmosphere., Meteorological data: Daily measurements of air temperature (ºC), wind speed (m s‐1) and humidity were provided by a meteorological station located in Lebrija (36º 58’ 35’‘N, 06º 07’ 34” W) maintained by the Junta de Andalucia (www.juntadeandalucia.es/agriculturaypesca/ifapa/ria/servlet/FrontController).-- Guadalquivir_estuary_meteorological_data.txt contains daily‐ensemble‐averaged wind velocities at 1 m (uz) above the land surface. SAMP.MONTH is the month in which the survey and samples collection took place. uz.ms is the monthly mean wind velocity at 1m above the land surface with units meters per second. T.degC is monthly mean air temperature at 1m above the land surface with units degrees Celcius. hum.% is the relative humidity at 1m above the land surface expressed as a percent., This data set includes recently published data used to assess the spatio‐temporal variability of dissolved methane and nitrous oxide in the Guadalquivir river estuary, SW Spain (Long: ‐6º 20´ 31.56´´, Lat: 36º 47´54´´, Datum: WSG84) between March 2016 and March 2017 and calculate air‐water fluxes of both gases., This research was supported by the project 1539/2015 (Spanish Ministry for Agriculture, Food and Environment). Meteorological data was provided by the Junta de Andalucia. NOOA supplied atmospheric methane and nitrous oxide data. Further analytical details, acknowledgements, and air‐water fluxes can be found in the publication., No

This data set includes measurements of water samples collected from 7 sites during 16 surveys carried out between March 2016 and March 2018 in the salt marshes of Doñana National Park. Geographic coordinates of sampling positions are provided. During samplings, in situ water conductivity (converted to salinity), temperature and pH were measured using a multi‐probe (YSI‐6920V2, YSI Incorporated, Yellow Springs, Ohio, USA) and water samples were collected for laboratory analysis of dissolved methane and nitrous oxide by static‐head space equilibration gas chromatography (GC) using an Agilent 7890 GC equipped with Flame Ionization Detector (FID) for CH4, according to de la Paz et al. (2015). Samples were also taken for analysis of phosphate, nitrate, nitrite and ammonia (with a Skalar Sanˆ++215 Continuous Flow Analyzer and using the standard colorimetric techniques described in Hansen and Koroleff 1999), dissolved oxygen and total alkalinity (using a Metrohm 794 Titroprocessor following the methods described by Mintrop et al. (2000) and Winkler) and dissolved organic carbon and total dissolved nitrogen that were determined through by catalytic oxidation at high temperature (720 °C) and chemiluminescence, respectively in a Shimadzu Total Organic Carbon analyzer (Model TOC‐VCPH/CPN), according to Álvarez‐Salgado and Miller (1998). Dissolved carbon dioxide partial pressure was calculated from pHNBS and total alkalinity using co2sys.xls (Pierrot et al., 2000) with the dissociation constants for carbon and sulfate of (Cai and Wang 1998) and (Dickson 1990), respectively., Calculations of the equilibrium concentrations of methane and nitrous oxide in the water phase was done using the annual averaged atmospheric mixing ratios CH4 (xCH4atm) provided by the World Data Center for Greenhouse Gases (http://ds.data.jma.go.jp/gmd/wdcgg/). Such mean value during the sampling period was calculated as 1866 ppb., Daily measurements of rainfall (mm), air temperature (ºC) and wind speed (m s‐1) were provided by ameteorological station located in Lebrija (36º 58’ 35’‘N, 06º 07’ 34” W) managed by the Junta de Andalucia (www.juntadeandalucia.es/agriculturaypesca/ifapa/ria/servlet/FrontController). The data is provided as [space] delimitated plain text files within a compressed folder that also includes a single README file (in PDF format) containing a detailed description of the data structure., For more details, see the publication: I. Emma Huertas, Mercedes de la Paz, Fiz F. Perez, Gabriel Navarro and Susana Flecha 2019. Methane emissions from the salt marshes of Doñana wetlands: spatio‐temporal variability and controlling factors. Frontiers in Ecology and Evolution, section Conservation., This dataset is subject to a Creative Commons License Attribution‐ShareAlike 4.0 International., [General Notes] The data are provided under an Attribution‐ShareAlike 4.0 International license. However, if you use thedata, so as to support the authors, please consider citing the above mentioned article where data collection and analytical techniques are given in detail. Here we only give a brief details and a guide to the contents of the data files. Data files are in UTF8 encoding, plain text format with {space} used as the delimiter and text enclosed in "". All data files have column titles as the first line. NA is used to represent no data., [Geographical coordinates of water sampling sites] Doñana_saltmarshes_sampling_stations_geo_coordinates.csv provides the geographical coordinates of the sites. ST.ID represents the code (used to link to other data tables) for each site. long and lat are longitude and latitude, respectively. Geographic projection and WSG84 datum is used (EPSG:4326)., [Water physiochemical properties] Doñana_saltmarshes_water_monitoring_2016‐2018.csv provides data from approximately monthly water sampling data between March 2016 and March 2018. Temperature, salinity and pH were measured with a multi‐probe (YSI‐6920V2, YSI Incorporated, Yellow Springs, Ohio, USA). Total alkalinity, concentrations of oxygen, organic carbon, organic nitrogen, inorganic nitrogen, pigments, suspended solids and dissolved phosphate were measured in the laboratory. pCO2 was calculated using pH and total alkalinity with co2sys.xls. SAMP.EVENT is a convenience code used to denominate each individual survey. SAMP.DATE is the day in which the sampling took place (in the Gregorian calendar). time.stamp.gmt is the time (GMT or UTC) at which the sample was collected, in extended ISO8601 format. ST.ID represents the code (used to link to other data tables) for each site. T.degC is the water temperature in degrees Celsius. Salinity is the water salinity (practical salinity units, i.e., no units), calculated from conductivity. CH4.nmolL is methane concentration with units nano mol per liter. Chla.μmolL is chlorophyll‐a concentration with units micro mol per liter. TSM.mgL is total suspended solids concentration with units milli gram per liter. DOC.mgL is total dissolved organic carbon concentration with units milli gram per liter. TDN.mgL is total dissolved nitrogen concentration with units milligram per liter. NH4.μmolL is dissolved ammonium concentration with units micro mol per liter. NO2.μmolL is dissolved nitrite concentration with units micro mol per liter. NO3.μmolL is dissolved nitrate concentration with units micro mol per liter. PO4.μmolL is dissolved inorganic phosphate concentration (i.e., not organic or total) with units micro mol per liter. O2.mgL is dissolved oxygen concentration with units mili gram per liter.TA.umolKg is total alkalinity with units micro mol per kilogram. pH is given using the National Bureau of Standards (NBS) scale at in situ temperature., [Meteorological data] Daily measurements of air temperature (ºC), wind speed (m s‐1) and humidity were provided by a meteorological station located in Lebrija (36º 58’ 35’‘N, 06º 07’ 34” W) maintained by the Junta de Andalucia (www.juntadeandalucia.es/agriculturaypesca/ifapa/ria/servlet/FrontController). Doñana_saltmarshes_meteorological_data.csv contains monthly‐ensemble‐averaged wind velocities at 1 m (uz) above the land surface with units meters per second. T.degC is monthly mean air temperature at 1m above the land surface with units degrees Celcius. hum.% is the relative humidity at 1m above the land surface expressed as a percent., This data set includes recently published data used to assess the spatio‐temporal variability of dissolved methane in the salt marshes of Doñana National Park, SW Spain (Long:‐6.373, Lat:36.932, Datum:WSG84) between March 2016 and March 2018 and calculate CH4 air‐water fluxes., This research was supported by the project 1539/2015 (Spanish Ministry for Agriculture, Food and Environment). Meteorological data was provided by the Junta de Andalucia. NOOA supplied atmospheric methane data. Further analytical details, acknowledgements, and airwater fluxes can be found in the publication., No

This dataset is composed of 2 files: a database (in csv format) with 695 records of biogeochemical variables (temperature, salinity, oxygen, nutrients, pH and total alkalinity) analyzed in water samples collected at the GIFT time series and a Readme (txt) file that includes a short description of the variables provided., If the dataset is used, please consider citing Flecha et al., (2019) (doi: 10.1038/s41598-019-52084-x)., This data set includes recently published data used to assess the temporal evolution of pH in Atlantic and Mediterranean water masses exchanging at the Strait of Gibraltar (Long:-5.345, Lat: 36.137, Datum:WSG84) during the decade 2005-2015 and to calculate the magnitude of natural and anthropogenic components on total pH changes (Flecha et al., 2019). The database provides measurements of carbon system parameters in water samples collected at 3 stations that form the marine time series GIFT during 26 oceanographic campaigns conducted over the decade 2005–2015. Geographic coordinates of sampling stations are provided. Some physical data (i.e. pressure, temperature and salinity) are also included. During the cruises, a temperature and salinity profile in each station was obtained with a Seabird 911 Plus CTD probe connected to a rosette sampler. Conductivity measurements were converted into practical values of the salinity scale with the UNESCO equation (1986). Seawater was subsequently collected for biogeochemical analysis using Niskin bottles immersed in the oceanographic rosette at variable depths (from 5 to 8 levels) depending on the instant position of the interface between the Atlantic and Mediterranean flows that was identified by CTD profiles. The biogeochemical variables shown in the database are pH in total scale at 25 °C (pHT25), total alkalinity (AT), Dissolved Oxygen (DO) and inorganic nutrients (nitrate, NO3− and Silicate, SiO44−). pHT25 data were obtained by the spectrophotometric method with m-cresol purple as indicator (Clayton & Byrne 1993) with an addition of 0.0047 (DelValls & Dickson, 1998). Samples were taken directly from the oceanographic bottles in 10 cm path-length optical glass cells and measurements were carried out with a Shimadzu UV-2401PC spectrophotometer containing a 25 °C-thermostated cells holder. Samples for AT analysis were collected in 500-ml borosilicate bottles, and poisoned with 100 μl of HgCl2-saturated aqueous solution and stored until measurement in the laboratory. AT was measured by potential titration according to Mintrop et al. (2000) with a Titroprocessor (model Metrohm 794). DO concentration was obtained through automated potentiometric modification of the original Winkler method using the Titroprocessor. Upon collection, flasks were sealed, stored in darkness and measured within 24 h. Water samples (5 mL, two replicates) for inorganic nutrients determination were taken, filtered immediately (Whatman GF/F, 0.7 μm) and stored frozen for later analyses in the shore-based laboratory. Nutrients concentrations were measured with a continuous flow auto-analyzer using standard colorimetric techniques (Hansen & Koroleff 1999). More details on procedures and data structure are given in a single README file (txt). The data are provided as [space] delimitated plain text files., Plan Estatal de I+D+i, European Commission, CSIC. CARBOOCEAN (FP6-511176), SESAME (FP6-036949), CARBOCHANGE (FP7-264879), PERSEUS (FP7-287600), COMFORT (H2020-820989), CTM2006-28141-E/MAR, CTM2016-75487-R., 1 data csv‘GIFT_carbonparameteres_2005_2015.csv’ file and 1 readme.txt file., Peer reviewed