Abstract
The structure of the planktonic community and the influence of mesozooplankton migration on the microbial food web were investigated during six diel studies from June 92 to June 93 in the surface waters of a station in the North-Western Mediterranean Sea. Each diel study consisted of sampling at 5 and 40 m every 3 h over 24 h. Most of the times diel cycles did not show any convincing diel patterns in any of the variables studied. Clear zooplankton migration was evident in only two diel studies.
The ratio of heterotrophic/autotrophic biomasses varied from 0.68 to 3.0, with a strong dominance of the heterotrophic biomass under oligotrophic conditions. Differences in food web structure were probably related to the influences of coastal water and the North-Western Mediterranean Current. Thus we found that the planktonic food web variability relatable to hydrodynamic variability, to be greater than diel variability. However, very large differences in food web structure among dates were evident. For example proportion of Chl a found in the <10 µm fraction varied from 18 to 96%.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Berk, S. G., D. C. Brownlee, D. Heinle, H. L. Kling & R. R. Colwell, 1977. Ciliates as food source for marine planktonic copepods. Microb. Ecol. 4: 27–40.
Bochdansky, A. B., S. Puskaric & G. J. Herndl, 1995. Influence of zooplankton grazing on free dissolved enzymes in the sea. Mar. Ecol. Prog. Ser. 12: 53–63.
Booth, B. C., J. Lewin & J. R. Postel, 1993. Temporal variation in the structure of autotrophic and heterotrophic communities in the subarctic Pacific. Prog. Oceanogr. 32: 57–99.
Børsheim, K. Y. & G. Bratbak, 1987. Cell volume to cell carbon conversion factors for a bacterivorous Monas sp. enriched from seawater. Mar. Ecol. Prog. Ser. 36: 171–175.
Conan, P. & C. Millot, Variability of the Northern Current off Marseilles, Western Mediterranean Sea, from February to June 1992. Oceanol. Acta 18(2), in press.
Cho, B. C. & F. Azam, 1990. Biogeochemical significance of bacterial biomass in the ocean's euphotic zone. Mar. Ecol. Prog. Ser. 63: 253–259.
Cushing, D. H., 1989. A difference in structure between ecosystems in strongly stratified waters and in those that are only weakly stratified. J. Plankton Res. 11: 1–13.
Davis, P. G., D. A. Caron, P. W. Johnson & J. McN. Sieburth, 1985. Phototrophic and apochlorotic components of picoplankton and nanoplankton in the North Atlantic: geographic, vertical, seasonal and diel distributions. Mar. Ecol. Prog. Ser. 21: 15–26.
Dortch, Q. & T. Packard, 1989. Differences in biomass structure between oligotrophic and eutrophic marine ecosystems. Deep-Sea Res. 36: 223–240.
Eppley, R. W., S. G. Horrigan, J. A. Fuhrman, E. R. Brooks, C. C. Price & K. Sellner, 1981. Origins of dissolved organic matter in Southern California coastal waters: Experiments on the role of zooplankton. Mar. Ecol. Prog. Ser. 6: 149–159.
Fuhrman, J. A. & F Azam, 1982. Thymidine incorporation as a measure of heterotrophic production in marine surface waters. Evaluation and field results. Mar. Biol. 66: 109–120.
Fuhrman, J. A., R. W. Eppley, Å. Hagström & F. Azam, 1985. Diel variations in bacterioplankton, phytoplankton, and related parameters in the Southern California Bight. Mar. Ecol. Prog. Ser. 27: 9–20.
Fuhrman, J. A., T. D. Sleeter, C. A. Carlson & L. M. Proctor, 1989. Dominance of bacterial in the Sargasso Sea and its ecological implications. Mar. Ecol. Prog. Ser. 57: 207–217.
Gaudy, R., 1974. Feeding four species of pelagic copepods under experimental conditions. Mar. Biol. 25: 125–141.
Herndl, G. J. & V. Malacic, 1987. Impact of the pycnocline layer on bactetioplankton: diel and spatial variations in microbial parameters in the stratified water column of the Gulf of Trieste, (Northern Adriatic Sea). Mar. Ecol. Prog. Ser. 38: 295–303.
Holligan, P. M., R. P. Harris, R. C. Newell, D. S. Harbour, R. N. Head, E. A. S. Linley, M. I. Lucas, P. R. G. Tranter & C. M. Weekley, 1984. Vertical distribution and partitioning of organic carbon in mixed, frontal and stratified waters of the English Channel. Mar. Ecol. Prog. Ser. 14: 111–127.
Kana, T. & P. M. Glibert, 1987. Effect of irradiances up to 2000 µEm−2 s−1 on marine Synechococcus WH 7803-I. Growth, pigmentation and cell composition. Deep Sea Res. 34: 479–516.
Kiørboe, T., H. Kaas, B. Kruse, F. Møhlenberg, P. Tiselius & G. Æertebjerg, 1990. The structure of the pelagic food web in relation to water column structure in the Skagerrak. Mar. Ecol. Prog. Ser. 59: 19–32.
Le Fèvre, J. & S. Frontier, 1988. Influence of temporal characteristics of physical phenomena on plankton dynamics, as shown by north-west European marine ecosystems. In: Toward a Theory of Biological-Physical Interactions in the World Ocean, Rotschild, B. J. (eds) Kluwer Academic Publishers, Dordrecht 245–272.
Lee, S. & J. A. Fuhrman, 1987. Relationships between biovolume and biomass of naturally derived marine bacterioplankton. Appl. envir. Microbiol. 53: 1298–1303.
McManus, G. B. & J. A. Fuhrman, 1990. Mesoscale and seasonal variability of heterotrophic nanoflagellate abundance in an estuarine outflow plume. Mar. Ecol. Prog. Ser. 61: 207–213.
Peduzzi, P. & G. J. Herndl, 1992. Zooplankton activity fueling the microbial loop: Differential growth response of bacteria from oligotrophic and eutrophic waters. Limnol. Oceanogr. 37: 1087–1092.
Piontkovski, S. A., R. Williams & T. A. Melnik, 1995. Spatial heterogeneity, biomass and size structure of plankton of the Indian ocean: some general trends. Mar. Ecol. Prog. Ser. 117: 219–227.
Riemann, B., N. O. G. Jørgensen, W. Lampert & J. A. Fuhrman, 1986. Zooplankton induced changes in dissolved free amino acids and in production rates in freshwater bacteria. Microb. Ecol. 12: 247–258.
Putt, M. & D. K. Stoecker, 1989. An experimentally determined carbon: biovolume ratio for marine ‘oligotrichous’ ciliates from estuarine and coastal waters. Limnol. Oceanogr. 34: 1097–1103.
Roman, M. R., H. W. Ducklow, J. A. Fuhrman, C. Garside, P. M. Glibert, T. C. Malone & G. B. McManus, 1988. Production, consumption and nutrient cycling in a laboratory mesocosm. Mar. Ecol. Prog. Ser. 42: 39–52.
Sheldon, R. W., P. Nival & F. Rassoulzadegan, 1986. An experimental investigation of a flagellate-ciliate-copepod food chain with some observations revelant to the linear biomass hypothesis. Limnol. Oceanogr. 31: 184–188.
Sorokin, Yu. I., A. I. Kopylov & N. V. Mamaeva, 1985. Abundance and dynamics of microplancton in the central tropical Indian Ocean. Mar. Ecol. Prog. Ser. 24: 27–41.
Stoecker, D. K. & J. M. Cappuzo, 1990. Predation on Protozoa: its importance to zooplankton. J. Plankton. Res. 12: 891–908.
Strickland, J. D. H. & T. R. Parsons, 1972. A practical hand-book of seawater analysis. 2nd ed. Bull. Fish. Res. Bd Can. 167: 1–311.
Utermöhl, H., 1958. Zur Vervollkommnung der quantitativen Phytoplankton Methodik. Mitt. int. Ver. Limnol. 9: 323–332.
Van Wambeke, F., U. Christaki & R. Gaudy. Carbon fluxes from the microbial food web to mesozooplankton. An approach in the surface layer of a pelagic area (NW Mediterranean Sea). Ocean. Acta, in press.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Christaki, U., Van Wambeke, F., Christou, E.D. et al. Food web structure variability in the surface layer, at a fixed station influenced by the North Western Mediterranean Current. Hydrobiologia 321, 145–153 (1996). https://doi.org/10.1007/BF00023170
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00023170