Summary
We have studied bottom-up and top-down control of the Southern Ocean microbial food web by microcosm experiments. Water from the Weddell Sea and Weddell Scotia Confluence were used for the experiments. Microcosms were manipulated by nutrients and light, and by size-selective screening. Incubation at the higher light level doubled phytoplankton growth rates from 0.12 to 0.24 day-1 in the Weddell experiment and from 0.15 to 0.30 day-1 in the Confluence experiment. Nutrient enrichment had no significant effect on growth rates in either of the experiments, indicating that phytoplankton growth was not nutrient-limited. In the microcosms where dinoflagellate growth rate was different, high dinoflagellate numbers were reflected as depressed nanoflagellate growth as well as depressed growth of phytoplankton, suggesting that dinoflagellates controlled both heterotrophic nanoflagellates and autotrophic nanoplankton. Only during short periods, when dinoflagellate numbers were low, could exponential growth of nanoflagellates be demonstrated. Bacterioplankton growth rates were, on average, 0.26 day-1 in the Weddell experiment and 0.22 day-1 in the Confluence experiment. Bacteria were controlled by heterotrophic nanoflagellates. Potential growth rates up to 0.75 day-1 were measured from batch cultures without predators. With the microcosm experiments, we could demonstrate a strong top-down control by dinoflagellates on phytoplankton and on heterotrophic nanoflagellates, and a control by heterotrophic nanoflagellates on bacteria. We could also demonstrate weak nutrient limitation on autotrophs and substrate limitation on heterotrophic bacteria. In the two study areas, biomass production and carbon flow were mediated mainly by organisms that passed through a 20 μm net and had growth rates in the order of 0.20 to 0.30 day-1.
Data presented here were collected during the European Polarstern Study (EPOS) sponsored by the European Science Foundation
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Bjørnsen PK, Kuparinen J (1991a) Determination of bacterioplankton biomass, net production and growth efficiency in the Southern Ocean. Mar Ecol Prog Ser 71:185–194
Bjornsen PK, Kuparinen J (1991b) Growth and herbivory by heterotrophic dinoflagellates in the Southern Ocean, studied by microcosm experiments. Mar Biol 109:397–405
Box GEP, Draper NR (1987) Empirical model-building and response surfaces. Wiley and Sons, New. York, pp 1–669
Haas LW (1982) Improved epifluorescence microscopy for observing planktonic microorganisms. Ann Inst Oceanogr 58:261–266
Hewes CD, Holm-Hansen O, Sakshaug E (1985) Alternate carbon pathways at lower trophic levels in the Antarctic food web. In: Siegfried WR, Condy PR, Laws RM (eds) Antarctic nutrient cycles and food webs. Springer, Berlin, pp 277–283
Hewes CD, Sakshaug E, Reid FMH, Holm-Hansen O (1990) Microbial autotrophic and heterotrophic eucaryotes in Antarctic waters: relationships between biomass and chlorophyll, adenosine triphosphate and particulate organic carbon. Mar Ecol Prog Ser 63:27–35
Hobbie JE, Daley RJ, Jasper S (1977) Use of Nuclepore filters for counting bacteria by fluorescence microscopy. Appl Environ Microbial 33:1225–1228
Kaitala S, Kuparinen J, Maximov VN (1984) The investigation of heavy metal and pentachlorophenolate stress on heterotrophic activity and primary productivity by means of factorial experiment. In: Dutka BJ, Liu D (eds) Toxicity screening procedures using bacterial Systems. Marcel Dekker, New York, pp 395–413
Lancelot C, Veth C, Mathot S (1991) Modelling ice-edge phytoplankton bloom in the Scotia-Weddell sea sector of the Southern ocean during spring 1988. J Mar Syst 2:333–346
Lorenzen CJ (1967) Determination of chlorophyll and phaeopigments: spectrophotometric equations. Limnol Oceanogr 12:343–346
Margolin BH (1967) Systematic methods for analyzing 2n3m factorial experiments with applications. Technometrics 9:245–259
Martin JH, Fitzwater SE (1988) Iron deficiency limits phytoplankton growth in the Northeast Pacific subarctic. Nature, London 331:341–343
Montgomery DC (1984) Design and analysis of experiments. Wiley and Sons, New York, pp 1–583
Nelson DM, Smith WO, Muench RD, Gordon LI, Sullivan CW, Husby DM (1989) Particulate matter and nutrient distribution in the ice-edge zone of the Weddell Sea: relationship to hydrography during late summer. Deep-Sea Res 36:191–209
Nelson DM, Smith WO Jr, Gordon LI, Huber B (1987) Early spring distributions of density, nutrients and phytoplankton biomass in the ice-edge zone of the Weddell/Scotia Sea. J Geophys Res 92:7181–7190
Perissinotto R, Duncombe Rae CM, Boden BP, Allanson BR (1990) Vertical stability as a controlling factor of the marine phytoplankton production at the Prince Edward Archipelago (Southern Ocean). Mar Ecol Prog Ser 60:205–209
Priddle J, Hawes I, Ellis-Evans JC, Smith TJ (1986) Antarctic aquatic ecosystems as habitats for phytoplankton. Biol Rev 61:199–238
Sakshaug E, Holm-Hansen O (1984) Factors governing pelagic production in polar oceans. In: Holm-Hansen O, Bolis L, Gilles R (eds) Marine phytoplankton and productivity. Springer, Berlin, pp 2–34
Smith WO (1987) Phytoplankton dynamics in marginal ice zones. Oceanogr Mar Biol Annu Rev 25:11–38
Smith WO, Nelson DM (1985) Phytoplankton bloom produced by a receding ice edge in the Ross Sea: spatial coherence with the density field. Science 227:163–166
Spies A (1987) Growth rates of Antarctic marine phytoplankton in the Weddell Sea. Mar Ecol Prog Ser 41:267–274
Sullivan CW, Cota GF, Krempin DW, Smith WO (1990) Distribution and activity of bacterioplankton in the marginal ice zone of the Weddell-Scotia Sea during austral spring. Mar Ecol Prog Ser 63:239–252
Thingstad TF, Sakshaug E (1990) Control of phytoplankton growth in nutrient recycling ecosystems. Theory and terminology. Mar Ecol Prog Ser 63:261–272
Veth C (1991) The evolution of the upper water layer in the marginal ice zone, austral spring 1988, Scotia-Weddell Sea. J Mar Syst 2:451–464
Weber LH, EL-Sayed SZ (1987) Contributions of the net, nano- and picoplankton to the phytoplankton standing crop and primary productivity in the Southern Ocean. J Plankton Res 9:973–994
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1992 Springer-Verlag
About this paper
Cite this paper
Kuparinen, J., Bjørnsen, P.K. (1992). Bottom-up and top-down controls of the microbial food web in the Southern Ocean: experiments with manipulated microcosms. In: Hempel, G. (eds) Weddell Sea Ecology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-77595-6_21
Download citation
DOI: https://doi.org/10.1007/978-3-642-77595-6_21
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-77597-0
Online ISBN: 978-3-642-77595-6
eBook Packages: Springer Book Archive