Description: Auto- and heterotrophic microbial activity (biomass production and respiration) were investigated in a cyclonic eddy that formed off Mauritania along the ∼ 900 km zonal corridor between Mauritania and the Cabo Verde islands in the eastern Tropical North Atlantic during the M156 cruise on the RV Meteor from July 3rd to August 1st 2019. The dataset includes measured and calculated data over the epipelagic layer (0-200 m depth) of 25 stations with 14 of them inside or in the vicinity of a cyclonic eddy. Temperature, salinity, and oxygen were obtained from a Seabird 911 plus CTD system equipped with two independently working sets of temperature–conductivity–oxygen. Seawater samples were collected using 10 L Niskin bottles attached to the CTD Rosette. Ammonium was analysed based on Solórzano (1969, https://doi.org/10.4319/lo.1969.14.5.0799) and nitrate, nitrite, phosphate and silicate were measured photometrically with continuous-flow analysis on an auto-analyser based on Hansen and Koroleff, (1999, https://doi.org/10.1002/9783527613984.ch10). To estimate the fraction of semi-labile dissolved organic carbon, we determined high-molecular-weight (〉1 kDa) dissolved combined carbohydrates (dCCHO) based on Engel and Händel (2011, https://doi.org/10.1093/plankt/fbq122) and dissolved hydrolysable amino acids (dHAA) based on Lindroth and Mopper (1979, https://https://doi.org/10.1021/ac50047a019) and Dittmar et al, (2009). The analysis of DCCHO detected 11 monomers: and the dHAA analysis classified 13 monomers. The calculations for the carbon content of dCCHO and dHAA were based on carbon atoms contained in the identified monomers. The sum of dCCHO and dHAA carbon content is referred to as SL-DOC. Chlorophyll a was measured from photometric analysis based on Evans et al, (1987). Heterotrophic bacteria, photosynthetic bacteria (Prochlorococcus and Synechococcus), and autotrophic pico and nanoplankton (〈20 μm) abundances were measured by flow cytometry. We converted the cell abundance of the different autotrophic pico- and nanoplankton populations into biomass based on Hernández-Hernández et al. (2020, https://doi.org/10.3389/fmars.2020.00667). Extracellular release rates, dissolved-, particulate- and total- primary production rates were determined from 14C incorporation according to Nielsen (1952, https://doi.org/10.1093/icesjms/18.2.117) and Gargas (1975). Community respiration was obtained from optode-based method from incubations by measuring changes in dissolved oxygen over 24–36 h. Bacterial biomass production rates were measured through the incorporation of labelled leucine (3H) using the microcentrifuge method (Kirchman et al., 1985, https://doi.org/10.1128/aem.49.3.599-607.1985; Smith and Azam, 1992, ). Community respiration and bacterial biomass production were converted to rates at 22°C using equations from Regaudie-De-Gioux and Duarte (2012, https://doi.org/10.1029/2010GB003907) and from López-Urrutia and Morán (2007, https://doi.org/10.1890/06-1641) respectively. Community respiration rates were converted to bacteria respiration rates based on Aranguren-Gassis et al, (2012, https://doi.org/10.3354/meps09707). Bacteria carbon demand and growth efficiency were calculated from bacterial production and respiration rates. Dittmar, T., Cherrier, J., and Ludwichowski, K. U.: The analysis of amino acids in seawater, in: Practical guidelines for the analysis of seawater, edited by: Wurl, O., 67–78, CRC Press, Boca Raton, ISBN: 978-1-4200-7306-5, 2009. Evans, C. A., O'Reily, J. E., and Thomas, J. P.: A handbook for measurement of Chl a and primary production, College Station, TX, Texas A and M University, ISBN:9780948277078, 0948277076, 1987. Gargas, E.: A Manual for Phytoplankton Primary Production Studies in the Baltic, The Baltic Marine Biologists, 2, 88 pp. Ed. Gargas E. (Hørsholm, Denmark: Water Quality Institute), 1975. Smith, D. and Azam, F.: A simple, economical method for measuring bacterial protein synthesis rates in seawater using, Mar. Microb. Food Webs, 6, 107–114, 1992.

Description: This dataset includes measured and calculated data over the epipelagic layer (0-200 m depth) of 25 stations with 14 of them inside or in the vicinity of a cyclonic eddy that formed off Mauritania along the ∼ 900 km zonal corridor between Mauritania and the Cabo Verde islands in the eastern Tropical North Atlantic during the M156 cruise on the RV Meteor from July 3rd to August 1st 2019. Chlorophyll a was measured from photometric analysis based on Evans et al, (1987).We converted the cell abundance of the different autotrophic pico- and nanoplankton populations into biomass based on Hernández-Hernández et al. (2020, https://doi.org/10.3389/fmars.2020.00667). Extracellular release rates, dissolved-, particulate- and total- primary production rates were determined from 14C incorporation according to Nielsen (1952, https://doi.org/10.1093/icesjms/18.2.117) and Gargas (1975).

Description: This dataset includes measured and calculated data over the epipelagic layer (0-200 m depth) of 25 stations with 14 of them inside or in the vicinity of a cyclonic eddy that formed off Mauritania along the ∼ 900 km zonal corridor between Mauritania and the Cabo Verde islands in the eastern Tropical North Atlantic during the M156 cruise on the RV Meteor from July 3rd to August 1st 2019. Bacterial biomass production rates were measured through the incorporation of labelled leucine (3H) using the microcentrifuge method (Kirchman et al., 1985, https://doi.org/10.1128/aem.49.3.599-607.1985; Smith and Azam, 1992). Bacteria carbon demand and growth efficiency were calculated from bacterial production and respiration rates. Dittmar, T., Cherrier, J., and Ludwichowski, K. U.: The analysis of amino acids in seawater, in: Practical guidelines for the analysis of seawater, edited by: Wurl, O., 67–78, CRC Press, Boca Raton, ISBN: 978-1-4200-7306-5, 2009. Evans, C. A., O'Reily, J. E., and Thomas, J. P.: A handbook for measurement of Chl a and primary production, College Station, TX, Texas A and M University, ISBN:9780948277078, 0948277076, 1987. Gargas, E.: A Manual for Phytoplankton Primary Production Studies in the Baltic, The Baltic Marine Biologists, 2, 88 pp. Ed. Gargas E. (Hørsholm, Denmark: Water Quality Institute), 1975. Smith, D. and Azam, F.: A simple, economical method for measuring bacterial protein synthesis rates in seawater using, Mar. Microb. Food Webs, 6, 107–114, 1992.

Description: This dataset includes measured and calculated data over the epipelagic layer (0-200 m depth) of 25 stations with 14 of them inside or in the vicinity of a cyclonic eddy that formed off Mauritania along the ∼ 900 km zonal corridor between Mauritania and the Cabo Verde islands in the eastern Tropical North Atlantic during the M156 cruise on the RV Meteor from July 3rd to August 1st 2019. Heterotrophic bacteria, photosynthetic bacteria (Prochlorococcus and Synechococcus), and autotrophic pico and nanoplankton (〈20 μm) abundances were measured by flow cytometry.

Description: This dataset includes measured and calculated data over the epipelagic layer (0-200 m depth) of 25 stations with 14 of them inside or in the vicinity of a cyclonic eddy that formed off Mauritania along the ∼ 900 km zonal corridor between Mauritania and the Cabo Verde islands in the eastern Tropical North Atlantic during the M156 cruise on the RV Meteor from July 3rd to August 1st 2019. To estimate the fraction of semi-labile dissolved organic carbon, we determined high-molecular-weight (〉1 kDa) dissolved combined carbohydrates (dCCHO) based on Engel and Händel (2011, https://doi.org/10.1093/plankt/fbq122) and dissolved hydrolysable amino acids (dHAA) based on Lindroth and Mopper (1979, https://https://doi.org/10.1021/ac50047a019) and Dittmar et al, (2009). The analysis of DCCHO detected 11 monomers: and the dHAA analysis classified 13 monomers. The calculations for the carbon content of dCCHO and dHAA were based on carbon atoms contained in the identified monomers. The sum of dCCHO and dHAA carbon content is referred to as SL-DOC. Community respiration was obtained from optode-based method from incubations by measuring changes in dissolved oxygen over 24–36 h. Community respiration and bacterial biomass production were converted to rates at 22°C using equations from Regaudie-De-Gioux and Duarte (2012, https://doi.org/10.1029/2010GB003907) and from López-Urrutia and Morán (2007, https://doi.org/10.1890/06-1641) respectively. Community respiration rates were converted to bacteria respiration rates based on Aranguren-Gassis et al, (2012, https://doi.org/10.3354/meps09707).

Description: This dataset includes measured and calculated data over the epipelagic layer (0-200 m depth) of 25 stations with 14 of them inside or in the vicinity of a cyclonic eddy that formed off Mauritania along the ∼ 900 km zonal corridor between Mauritania and the Cabo Verde islands in the eastern Tropical North Atlantic during the M156 cruise on the RV Meteor from July 3rd to August 1st 2019. Mixed layer depth and surface chlorophyll-a concentrations are shown.

Description: This dataset includes measured and calculated data over the epipelagic layer (0-200 m depth) of 25 stations with 14 of them inside or in the vicinity of a cyclonic eddy that formed off Mauritania along the ∼ 900 km zonal corridor between Mauritania and the Cabo Verde islands in the eastern Tropical North Atlantic during the M156 cruise on the RV Meteor from July 3rd to August 1st 2019. To extrapolate BP and CR rates to 22°C, we used equations from López-Urrutia and Morán for BP (BPU; 2007) and from Regaudie de Gioux and Duarte for CR (CRRG; 2012). we compared the rates of BP and CR measured ex-situ (BP_ex-situ and CR_ex-situ) with the rates obtained from BPU (BPU_14°C) and CRRG (CRRG_average temperature) at the temperature set during the incubations. References: López-Urrutia and Morá ,2007(https://doi.org/10.1890/06-1641); Regaudie de Gioux and Duarte, 2012 (https://doi.org/10.1029/2010GB003907)

Description: This dataset includes measured and calculated data over the epi-mesopelagic layer (0-450 m depth) of 29 stations with 4 stations within a cyclonic eddy nearby Brava island, 5 stations within a cyclonic eddy nearby Sal island, and one station within an anticyclonic eddy around the Cabo Verde islands in the eastern Tropical North Atlantic during the M160 cruise on the RV Meteor from November 22nd to December 20th, 2019. Duplicate samples for dissolved organic carbon (DOC) and total dissolved organic nitrogen (TDN) were filtered through 0.45 μm GMF GD/X filters (Whatman, GE Healthcare Life 248 Sciences, UK) and collected in combusted glass ampoules. Syringes and filters were rinsed with 25 and 50 mL of sample, respectively in order to remove potential contaminations. Samples were acidified with 20 μL of hydrochloric acid (30%) and stored at 4°C until analysis by high−temperature combustion using a Shimadzu TOC−VCSH after Engel & Galgani (2016). Values of TDN were corrected with dissolved inorganic nitrogen (nitrate+nitrite) and thereafter referred to as dissolved organic nitrogen (DON). To estimate the fraction of semi-labile dissolved organic carbon and semi-labile dissolved organic nitrogen, we determined high-molecular-weight (〉1 kDa) dissolved combined carbohydrates (dCCHO) based on Engel and Händel (2011, https://doi.org/10.1093/plankt/fbq122) and dissolved hydrolysable amino acids (dHAA) based on Lindroth and Mopper (1979, https://doi.org/10.1021/ac50047a019) and Dittmar et al, (2009). The analysis of DCCHO detected 11 monomers: and the dHAA analysis classified 13 monomers. The calculations for the carbon and nitrogen contents of dCCHO and dHAA were based on carbon and nitrogen atoms contained in the identified monomers. The sum of dCCHO and dHAA carbon and nitrogen contents are referred to as SL-DOC and SL-DON respectively. Size class of virus abundance measured by flow cytometry.

Description: This dataset includes measured and calculated data over the epi-mesopelagic layer (0-450 m depth) of 29 stations with 4 stations within a cyclonic eddy nearby Brava island, 5 stations within a cyclonic eddy nearby Sal island, and one station within an anticyclonic eddy around the Cabo Verde islands in the eastern Tropical North Atlantic during the M160 cruise on the RV Meteor from November 22nd to December 20th, 2019. Virus like particles size classes and heterotrophic bacteria (low and high nucleic abundance) were measured by flow cytometry.

Description: This dataset includes measured and calculated data over the epi-mesopelagic layer (0-450 m depth) of 29 stations with 4 stations within a cyclonic eddy nearby Brava island, 5 stations within a cyclonic eddy nearby Sal island, and one station within an anticyclonic eddy around the Cabo Verde islands in the eastern Tropical North Atlantic during the M160 cruise on the RV Meteor from November 22nd to December 20th, 2019. Chromophoric and fluorescent dissolved organic matter were measured with a Shimadzu® 1800 UV−VIS double beam spectrophotometer and a Cary Eclipse Fluorescence Spectrophotometer respectively. The data included the absorption coefficient at 325 nm (a325) and the four fluorescent components obtained from PARAFAC analysis.