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Temporal Variations of Benthic Bacterial Microflora on the Northwestern Mediterranean Continental Shelf and Slope
Author(s) -
Delille Daniel,
Guidi Laurence D.,
Cahet Guy
Publication year - 1990
Publication title -
marine ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.668
H-Index - 58
eISSN - 1439-0485
pISSN - 0173-9565
DOI - 10.1111/j.1439-0485.1990.tb00232.x
Subject(s) - heterotroph , benthic zone , continental shelf , organic matter , environmental science , photic zone , mediterranean climate , mediterranean sea , oceanography , bacterioplankton , total organic carbon , pelagic zone , submarine pipeline , ecology , biology , geology , bacteria , nutrient , phytoplankton , genetics
. Bacterial (direct and heterotrophic counts, heterotrophic potentials) and organic matter (org C, org N) parameters were studied over 2 years in the surface sediments of 3 stations located on the continental shelf (station A: 15m; station B: 35m) and slope (station C: 910m) in the northwestern Mediterranean Basin. Although logistic constraints did not allow a satisfactory sampling periodicity in the offshore survey, some seasonal trends were still observable at the deepest station. Variations were quantitatively more important in the two shallow sediments (from 3×10 2 heterotrophic bacteria – ml ‐1 in December 1984 to 10 7 heterotrophic bacteria‐ml ‐1 in March 1986). Epifluorcsccncc direct counts were relatively constant (5×10 8 cells‐ml ‐1 ), while heterotrophic potentials (with 14 C labelled glucose and glutamic acid) showed a succession of very short pulses over the year. Different concentrations of organic matter (from 0.2% orgC at 15m to 0.8% orgC at 35m) appeared to sustain very similar bacterial numbers. Nevertheless, a certain relation between the seasonal evolution of bacterial and organic matter parameters was discernable. Although depth apparently had no measurable effect on maximal spring bacterial densities, it seemed to lessen the summer and winter decreases in the two shallow stations.