Microbe abundance and biomass at station SEPT-1999-K1 in the Northeastern Aegean Sea
2019-11-21T20:41:11Z (GMT) by
Borax-buffered formalin (final concentration 2% formaldehyde). Slides for nanoflagellates counting were stored at -20°C. Subsamples (10-30 ml) were concentrated on 25mm black polycarbonate filters of porosity 0.6µm for nanoflagellates, stained with DAPI for 10 min (Porter & Feig 1980) and filtered. Heterotrophic (HF) and photototrophic (PF) nanoflagellates were distinguished using UV and blue excitation and enumerated. Nanoflagellates were classified in size categories and the biovolume was calculated. Abundance data were converted into C biomass using 220fgC um-3 (Borsheim & Bratbak 1987) for nanoflagellates. Bacterial production was estimated by the 3H-leucine method (Kirchman et al. 1986, Kirchman 1993). At each depth, duplicate samples and a control were incubated with 1 nM L-[4,5 3H]-leucine (specific activity 128 Ci mmol-1) and 19 nM non radioactive leucine. Samples were incubated in the dark, at in situ temperature.