Biogeochemistry and microbiology measurements in the Cariaco Basin. Microbiology sampling were conducted during special CARIACO cruises (distinct from the monthly, core sampling, time-series cruises) from November 1995 to November 2015. The specialized microbiology cruises were usually during May and November, and could be opportunistic or process-driven. There were typically at least 2 cruises per year, during which different variables were sampled and at different depths from the standard monthly CARIACO cruises. Bacteria production data were also reported for the microbiology cruises. access_formats=.htmlTable,.csv,.json,.mat,.nc,.tsv,.esriCsv,.geoJson,.odvTxt acquisition_description=## Sampling

Ocean time series samples are collected in standard 8L Niskin bottles. For samples in and below the oxycline, a nitrogen line is attached to the upper air vent to prevent air from entering the bottle during subsampling. Samples for live analysis are first transferred without headspace to a 1L glass sample bottle with Teflon standard taper stopper. In the ship's lab, subsamples are transferred to 25 or 40 ml incubation vials, also under nitrogen. All vials are filled from the bottom with overflow of about 3 vial volumes and then sealed with no headspace.

Low molecular weight fatty acids: Volatile fatty acids are measured using the technique developed by Yang (1991), Yang et al. (1993) and Wu and Scranton (1994). Detection limits are about 1 (M for acetate). However, in some cases, deep water values are lower than 1 micromolar for acetate in which case we have estimated blanks in individual files. Samples are poisoned with 1 ml 10N KOH per liter.

Fatty acid uptake rate constants: Acetate uptake rate constants are determined using radiolabeled tracers as described by Wu and Scranton (1994). Incubations are done anoxically in the dark in screw-top septum vials. Uptake includes both conversion of isotope to CO2 (respiration) and to biomass which can be filtered onto a 0.2 m Nuclepore filter (incorporation).

CH4:

CH4 is assayed by gas chromatography using the vial equilibration technique of Johnson et al. (1990) and a Carle 211AC gas chromatograph. Samples are poisoned by addition of 10N KOH solution at a rate of 200 l per 50 ml vial.

H2S:

Samples for sulfide analysis are taken in well-flushed glass syringes without bubbles and are injected into vials containing Zn-acetate. Upon return to the laboratory, the ZnS is dissolved and is analyzed spectrophotometrically by the method of Cline (1969).

Microbial census:

Abundances of remineralizers (bacteria) and regenerators (protozoa) are determined using microscopic censuses. Preserved samples (2% formaldehyde) are stained with a fluorochrome (DAPI or acridine orange) and captured on the appropriate porosity Nuclepore membrane (0.2 or 0.8 m). Filter-retained cells are enumerated and sized by epifluorescence microscopy according to Taylor et al. (1986). Larger, less abundant protozoa are enumerated on settled samples using inverted microscopy. Abundance and distribution of methanogens are determined by an autofluorescence microscopic technique whereby the fluorescence of coenzymes F420 and F350 in cells produced by two sets of excitation and barrier filters is considered presumptive identification of methanogens (Doddema and Vogels 1978).

Bacterial production:

Bacterial incorporation is measured using 3H-leucine incorporation as described by Kirchman (1993). Triplicate samples are incubated for 10-12 h in gas-tight screw-top vials to minimized alteration of the redox potential. Time course experiments have confirmed that uptake is linear for at least 15 hours. Due to the fact that some important anaerobic bacteria appear to not take up exogenous thymidine under anoxic conditions (McDonough et al. 1986; Gilmour et al. 1990), the more common method of Fuhrman and Azam (1982) is inappropriate for this system. awards_0_award_nid=54791 awards_0_award_number=OCE-0326268 awards_0_data_url=http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=0326268 awards_0_funder_name=NSF Division of Ocean Sciences awards_0_funding_acronym=NSF OCE awards_0_funding_source_nid=355 awards_0_program_manager=Donald L. Rice awards_0_program_manager_nid=51467 awards_1_award_nid=54828 awards_1_award_number=OCE-9711318 awards_1_data_url=http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=9711318 awards_1_funder_name=NSF Division of Ocean Sciences awards_1_funding_acronym=NSF OCE awards_1_funding_source_nid=355 awards_1_program_manager=Donald L. Rice awards_1_program_manager_nid=51467 awards_2_award_nid=54835 awards_2_award_number=OCE-9415790 awards_2_data_url=http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=9415790 awards_2_funder_name=NSF Division of Ocean Sciences awards_2_funding_acronym=NSF OCE awards_2_funding_source_nid=355 awards_2_program_manager=Donald L. Rice awards_2_program_manager_nid=51467 awards_3_award_nid=54919 awards_3_award_number=OCE-0752139 awards_3_data_url=http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=0752139 awards_3_funder_name=NSF Division of Ocean Sciences awards_3_funding_acronym=NSF OCE awards_3_funding_source_nid=355 awards_3_program_manager=Donald L. Rice awards_3_program_manager_nid=51467 cdm_data_type=Other comment=CARIACO Time-series biogeochemistry and microbiology measurements in the CARIACO Basin

n.a. = not available b.d. = winkler titration or sulfide analysis gave negative number SD = calculated standard deviation
lost = sample lost n.s. = correlation coefficient for slope of acetate uptake or respiration <0.8; therefore rate not significant

FLAGS n.f. = no flag a = Below reported detection limit (details in metadata file) b = No replicates c = flag included if precision >10% AND concentrations > 2 micromoles per liter H2S OR 0.05 micromoles per liter CH4 d = flag included if precision >20% AND concentrations > 2 micromoles per liter H2S OR 0.05 micromoles per liter for CH4 e = TZVS samples extracted for 60 minutes rather than 30 minutes

PI: Mary Scranton and Gordon T. Taylor

Version: 2019-06-03 Previous version 2018-12-07 Previous version 5 May 2016 Previous version 13 June 2012 Previous version 3 January 2010 Conventions=COARDS, CF-1.6, ACDD-1.3 data_source=extract_data_as_tsv version 2.3 19 Dec 2019 defaultDataQuery=&time<now doi=10.1575/1912/bco-dmo.3120.1 Easternmost_Easting=-64.54 geospatial_lat_max=10.716 geospatial_lat_min=10.45 geospatial_lat_units=degrees_north geospatial_lon_max=-64.54 geospatial_lon_min=-65.587 geospatial_lon_units=degrees_east geospatial_vertical_max=1353.0 geospatial_vertical_min=4.0 geospatial_vertical_positive=down geospatial_vertical_units=m infoUrl=https://www.bco-dmo.org/dataset/3120 institution=BCO-DMO instruments_0_acronym=Niskin bottle instruments_0_dataset_instrument_nid=4870 instruments_0_description=A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24 or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc. instruments_0_instrument_external_identifier=https://vocab.nerc.ac.uk/collection/L22/current/TOOL0412/ instruments_0_instrument_name=Niskin bottle instruments_0_instrument_nid=413 instruments_0_supplied_name=Niskin Bottle instruments_1_acronym=Gas Chromatograph instruments_1_dataset_instrument_description=CH4 is assayed by gas chromatography using the vial equilibration technique of Johnson et al. (1990) and a Carle 211AC gas chromatograph. instruments_1_dataset_instrument_nid=769439 instruments_1_description=Instrument separating gases, volatile substances, or substances dissolved in a volatile solvent by transporting an inert gas through a column packed with a sorbent to a detector for assay. (from SeaDataNet, BODC) instruments_1_instrument_external_identifier=https://vocab.nerc.ac.uk/collection/L05/current/LAB02/ instruments_1_instrument_name=Gas Chromatograph instruments_1_instrument_nid=661 instruments_1_supplied_name=Carle 211AC gas chromatograph instruments_2_acronym=Spectrophotometer instruments_2_dataset_instrument_description=Upon return to the laboratory, the ZnS is dissolved and is analyzed spectrophotometrically by the method of Cline (1969). instruments_2_dataset_instrument_nid=769440 instruments_2_description=An instrument used to measure the relative absorption of electromagnetic radiation of different wavelengths in the near infra-red, visible and ultraviolet wavebands by samples. instruments_2_instrument_external_identifier=https://vocab.nerc.ac.uk/collection/L05/current/LAB20/ instruments_2_instrument_name=Spectrophotometer instruments_2_instrument_nid=707 instruments_2_supplied_name=spectrophotometrically metadata_source=https://www.bco-dmo.org/api/dataset/3120 Northernmost_Northing=10.716 param_mapping={'3120': {'Corrected_Depth': 'flag - depth', 'Latitude': 'flag - latitude', 'Longitude': 'flag - longitude', 'ISO_DateTime_UTC': 'flag - time'}} parameter_source=https://www.bco-dmo.org/mapserver/dataset/3120/parameters people_0_affiliation=Estacion de Investigaciones Marinas de Margarita people_0_affiliation_acronym=EDIMAR-FLASA people_0_person_name=Yrene Astor people_0_person_nid=51110 people_0_role=Co-Principal Investigator people_0_role_type=originator people_10_affiliation=Estacion de Investigaciones Marinas de Margarita people_10_affiliation_acronym=EDIMAR-FLASA people_10_person_name=Jesus Narvaez people_10_person_nid=769558 people_10_role=Technician people_10_role_type=related people_11_affiliation=University of South Florida people_11_affiliation_acronym=USF people_11_person_name=Laura Lorenzoni people_11_person_nid=51044 people_11_role=Data