PI = Dr. Mary Scranton and G. T. Taylor, SUNY Stony Brook Project = Cariaco-1 Program Data = Acetate Uptake rates of bacteria, bacteria and phytoplankton cell counts Ship = Hermano Gines (operated by Fundacion la Salle, Punta de Piedras, Isla Margarita, Venezuela) Cruise designator = CAR-1 Station Location = 10.50N and 64.66W (all samples collected at this location) Cast Dates = cast 1: Begun at 2230, 13 Nov 1995; end 2359 cast 2: Begun at 0530, 14 Nov 1995; end 0630 cast 3: Begun at 0830, 14 Nov 1995; end 0945 sd = Standard deviation Untake rate constants (incorporation and respiration) = rate constants (essentially fraction uptake per unit time) for uptake (incorporation and respiration) of acetate by whole water as collected by Niskin. We have not done any size fractionation, but we expect that the uptake is largely by the cells counted under total bacteria (although there are probably some phyto- plankton as well) Corr. Uptake rate,Uptake rate, Depth,Acetate,H2S ,CH4, ,Incorp. ,Respiration, Total Bacteria , Cyanobacteria , Methanogens , Flagellates ,Bacterial Production cast,m ,umolar ,umolar,umolar,per hr ,per hr ,cells/L , sd ,cells/L , sd ,cells/L , sd ,cells/L , sd ,ngC/L/d), sd 2, 7, 1 , -.9, -.9 , 0.0016 ,0.00135 ,6.01E+08,2.10E+07,3.65E+07,5.52E+06,4.01E+05,1.05E+05,1.22E+05,2.85E+04,116.72 ,67.37 2, 15, 2.8 , -.9, 0.02, -.9 ,-.9 ,5.08E+08,6.07E+07,3.75E+07,3.89E+06,4.39E+05,1.05E+05,1.22E+05,3.06E+04, 59.13 , -.9 2, 55, 2.3 , -.9, 0.02, 0.0006 ,0.0004 ,4.01E+08,7.00E+06,4.66E+06,3.98E+05,6.88E+05,1.58E+05,1.76E+05,3.72E+04,144.75 , -.9 2, 75, 1.1 , -.9, 0.02, -.9 ,-.9 ,3.23E+08,4.28E+07,1.03E+06,1.40E+05,2.29E+05,5.00E+04,3.82E+04,3.82E+04,120.19 ,49.55 2, 100, 2.6 , -.9, 0.02, 0.0002 ,0.0001 ,2.30E+08,7.78E+06,1.03E+06,1.40E+05,1.15E+06,2.15E+05,2.29E+04,1.25E+04, 0.* , 0 2, 150, 1 , -.9, 0.02, 0.000045 ,0.000005 ,1.40E+08,1.32E+07,7.26E+05,1.55E+05,1.22E+06,1.87E+05,1.53E+04,1.05E+04, 15.34 ,10.62 2, 162, 0.8 , -.9, 0.01, 0.000005 ,0.000045 ,1.40E+08,6.22E+06,8.02E+05,2.38E+05,8.40E+05,1.61E+05,4.58E+04,2.50E+04, 0.* ,0 3, 220, 0.8 , -.9, 0.01, 0.00025 ,0.0002 ,2.70E+08,1.01E+07,5.73E+05,8.50E+04,9.93E+05,2.78E+05,7.64E+03,7.64E+03, 0.* ,0 3, 240, 3 , -.9, -.9 , 0.0008 ,0.00085 ,3.53E+08,1.71E+07,1.07E+06,1.59E+05,1.05E+06,2.16E+05,1.38E+05,3.66E+04, 31.76 ,32.79 3, 249, 4.4*, 4.1, 0.11, 0.00105 ,0.0014 ,3.82E+08,4.59E+07,8.79E+05,1.51E+05,5.54E+05,1.45E+05,9.17E+04,2.33E+04, 36.68 , -.9 3, 258, 2.7 , 4.5, 0.21, 0.0007 ,0.00065 ,3.33E+08,5.45E+06,5.35E+05,1.42E+05,9.74E+05,2.33E+05,3.60E+05,5.60E+04, 36.13 , -.9 3, 299, 3.7 , 5.5, 0.39, 0.0004 ,0.0001 ,3.25E+08,2.33E+07,6.88E+05,1.25E+05,1.53E+05,8.50E+04,6.65E+05,1.17E+05, 70. ,82.23 3, 318, 13.4*, 8.9, 0.65, 0.0003 ,0.000005 ,1.83E+08,9.33E+06,6.11E+05,1.73E+05,2.29E+05,6.40E+04,4.20E+05,7.83E+04, 0.* ,0 1, 338, 5.2 , 15.8, 1.06, 0.0003 ,0.000005 ,1.73E+08,3.89E+06,1.53E+05,6.20E+04,4.07E+05,1.32E+05,2.60E+05,4.01E+04, 0.* ,0 1, 347, 2.9 , 15.5, 1.36, -.9 ,-.9 ,1.30E+08,4.67E+06,1.53E+05,1.17E+05,2.67E+05,6.30E+04,3.00E+05,5.00E+04, 0.* ,0 1, 360, 2.5 , 19.7, 1.67, 0.00025 ,0.000005 ,1.67E+08,1.24E+07,5.35E+05,1.02E+05,4.23E+05,6.10E+04,1.30E+05,3.55E+04, 0.* ,0 1, 378, 3.5 , 21.6, 0.93, 0.00015 ,0.000005 ,1.29E+08,7.78E+06,4.97E+05,1.62E+05,8.79E+05,1.66E+05,3.13E+05,4.50E+04, 0.* ,0 1, 398, 3.8 , 26.6, 2.17, 0.000005 ,0.000005 ,1.02E+08,1.23E+07,2.67E+05,8.20E+04,2.86E+05,1.54E+05,3.30E+05,4.20E+04, 0.* ,0 1, 448, 2.2 , 29.5, 3.16, -.9 ,-.9 ,1.24E+08,-.9 ,3.80E+04,3.80E+04,8.43E+05,2.93E+05,3.34E+05,8.18E+04, 0.2 , 0.28 1, 498, 0.7 , 40.5, 4.01, 0.000005 ,0.000005 ,1.10E+08,4.51E+06,1.15E+05,5.80E+04,8.98E+05,1.60E+05,1.38E+05,4.56E+04, 0.* ,0 1, 744, 2 , 62.4, 8.0 , 0.000005 ,0.000005 ,9.72E+07,5.45E+06,-.9 ,-.9 ,1.43E+06,1.66E+05,1.38E+05,3.49E+04, 0.* ,0 1, 902, 2.0*, 72.9, 8.22, 0.000005 ,0.000005 ,1.02E+08,3.11E+06,7.60E+04,7.60E+04,1.59E+06,2.27E+05,1.07E+05,2.95E+04, 11.67 ,16.5 1,1190, 4.3 , 76.2, 11.92, 0.000005 ,0.000005 ,7.60E+07,7.78E+05,2.29E+05,6.20E+04,1.24E+06,2.48E+05,9.93E+04,3.38E+04, 0.* ,0 -.9 = not determined Acetate and CH4 values are not blank corrected. Blank for acetate is approx. 0.7 micromolar. Blank for CH4 is approx. 0.02 micromolar. Acetate values with asterisk are questioned due to low (<80%) concentration factor. Bacterial Production values with as asterisk are below level of detection. Meta data: Methods Sampling: All samples are collected in standard 8L Niskin bottles. For samples in and below the oxycline, a N2 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 N2. 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 mM for acetate and about 10 nM for the other fatty acids. 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). Chemoautotrophy: Rates of chemoautotrophic carbon fixation are estimated using 14C-bicarbonate as a tracer. 14C is added to seawater in glass incubation vials sealed with Teflon-lined butyl rubber septa and are incubated in the dark at in situ temperatures. The procedure minimizes the alteration of natural pH and/or redox conditions of the seawater sample. After 24 h incubations, samples are filtered through 0.22 * nitrocellulose filters, rinsed and placed in an HCl-saturated atmosphere to removed residual inorganic 14C (Tuttle and Jannasch 1973). A preliminary time course experiment demonstrated that uptake is linear for the first 48 hours. Dried filters are radioassayed by LSC. 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 h. 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. Cline, J.D. (1969) Spectrophotometric determination of hydrogen sulfide in natural waters. Limnol. Oceanogr., 14, 454-458. Doddema, H.J. and G.D. Vogels (1978) Improved identification of methanogenic bacteria by fluorescence microscopy. Appl. Environ. Microbiol., 36, 752-754. Fuhrman, J.A. and F. Azam (1982) Thymidine incorporation as a measure of heterotrophic bacterioplankton production in marine surface waters: evaluation and field results. Mar. Biol., 66. 109-120. Gilmour, C.C., M.E. Leavitt and M.P. Shiaris (1990) Evidence against incorporation of exogenous thymidine by sulfate-reducing bacteria. Limnol. Oceanogr., 35, 1401-1409. Johnson, K.M., J.E. Hughes, P.L Donaghay and J.McN. Sieburth (1990) Bottle calibration static headspace method for the determination of methane dissolved in seawater, Anal. Chem., 62, 2408-2412. Kirchman, D.L. (1993) Leucine incorporation as a measure of biomass production by heterotrophic bacteria. In: Kemp, P.F., B.F. Sherr, E.B. Sherr and J.J. Cole (eds.) Handbook of Methods in Aquatic Microbial Ecology, Lewis Publ., Boca Raton, pp., 509- 512. McDonough, R.J., R.W. Sanders, K.G. Porter and D.C. Kirchman (1986) Depth distribution of bacterial production in a stratified lake with an anoxic hypolimnion. Appl. Environ. Microbiol., 52, 992-1000. Taylor, G.T., D.M. Karl and M.L. Pace (1986) Impact of bacteria and zooflagellates on the composition of sinking particles: an in situ experiment. Mar. Ecol. Prog. Ser., 29, 141-155. Tuttle, J.H. and H.W. Jannasch (1973) Sulfide and thiosulfate- oxidizing bacteria in anoxic marine basins. Mar. Biol., 20, 64- 70. Wu, H. and M.I. Scranton (1994) Cycling of acetate and propionate in the waters of a permanently anoxic estuarine basin. Mar. Chem., 47, 97-113. Yang, X.H. (1991) Concentrations and biological uptake of three methylamines in marine, estuarine and lacustrine waters. MS thesis, SUNY at Stony Brook, 158 pp. Yang, X.-H., C. Lee and M.I. Scranton. (1993) Determination of nanomolar amounts of individual dissolved low molecular weight amines and organic acids in seawater. Analytical Chemistry, 65, 572-576. NODC Data Submission by M.I. Scranton and G.T. Taylor, SUNY, Stony Brook The CARIACO program CARIACO 1 (November 1995)