Fluctuations in the community composition of water-column protozoa in two southeastern blackwater rivers (Georgia, USA)

Hydrobiologia - Tập 185 - Trang 55-62 - 1989
Leslie A Carlough1
1Institute of Ecology, Department of Zoology, University of Georgia, Athens, USA

Tóm tắt

This study addresses protozoan population dynamics of two southeastern blackwater rivers in Georgia: the sixth order Ogeechee River and fourth order Black Creek. The density and composition of the protozoan community was assessed by counting the protozoans into size classes. Particularly abundant flagellate types (bloom forms) and ciliates were enumerated separately. Protozoan density in these blackwater rivers is high. Observations during a two week and a ten month census showed that the rate of community change is rapid and that the range in diversity is great. A backwater site showed the highest percentage of bloom forms, while the main channel sites of Black Creek and the Ogeechee River had fewer bloom forms. Rapid increases in density during a two week microcosm study were attributed to isolation of the water-column from filter-feeders, the benthos, and different source areas. An analogous situation may exist in the low order swamp streams and backwater habitats where many dense blooms occur. The high protozoan population densities observed were partially due to rapid changes in the physical characteristics of the environment, reactions of the protozoa to such changes, growth in the swamp tributaries and backwater areas, subsequent washing into the river, and further growth as the water moves toward the sea.

Tài liệu tham khảo

Baldock, B. M., J. H. Baker & M. A. Sleigh, 1983. Abundance and productivity of protozoa in chalk streams. Holarct. Ecol. 6: 238–246. Bamforth, S. S., 1973. Population dynamics of soil and vegetation protozoa. Am. Zool. 13: 171–176. Benke, A. C. & J. L. Meyer, 1988. Structure and function of a blackwater river in the southeastern U.S.A. Proc. Internat. Assoc. Theoretical & Applied Limnology. 23: 1209–1218. Bereczky, M. S., 1980. Wirkung des vom Warmenkraftwerk von Szaahalombatta abgellasen Erwarmten Kuhlwassers auf die einzellige Fauna sowie aufnahme des grundzustandes im Raum von Paks. Ann. Univ. Sci. Budapest, Sect. Biol. 12–13: 145–158. Brooks, J. L. & S. I. Dodson, 1965. Predation, body size and composition of plankton. Science 150: 28–35. Cairns, J. Jr., 1964. The chemical environment of common freshwater protozoa. Not. Nat. Acad. Nat. Sci. Phil. 365: 1–6. Cairns, J. Jr., 1965a. The environmental requirements of the protozoa. Biological problems in water pollution, Third seminar. 1962. PHS Publ. No. 999-WP-25 48–52. Abst. 385–386. Cairns, J. Jr., 1965b. The protozoa of the Conestoga Basin. Not. Nat. Acad. Nat. Sci. Phil. 375: 1–14. Cairns, J. Jr., 1966. The protozoa of the Potomac River from Point of Rocks to Whites Ferry. Not. Nat. Acad. Nat. Sci. Phil. 387: 1–11. Cairns, J. Jr., 1971. Factors affecting the number of species in freshwater protozoan communities. In J. Cairns (ed.), Symposium on the structure and function of freshwater microbial communities, Amer. Microsc. Soc., Virginia Polytechnic Inst. and State Univ. Press, Richmond VA: 219–247. Cairns, J. Jr. & W. H. Yongue Jr., 1968. The distribution of freshwater protozoa on a relatively homogeneous substrate. Hydrobiologia 31: 65–72. Cairns, J. Jr. & W. H. Yongue Jr., 1977. Factors affecting the number of species in freshwater protozoan communities. In J. Cairns Jr. (ed.), Aquatic Microbial Communities. Garland Publishing Inc., N.Y. 257–303. Cairns, J. Jr., J. A. Ruthven & R. L. Kaesler, 1974. Distribution of protozoa in a small stream. Am. Midl. Nat. 92: 406–414. Carlough, L. A. & J. L. Meyer, 1989. Protozoans in two southeastern blackwater rivers and their importance to trophic transfer. Limnol. Oceanogr. 34: 163–177. Corllis, J. O. & S. C. Esser, 1974. Comments on the role of cysts. Life cycle and role of freeliving protozoa. Trans. amer. microsc. Soc. 93: 578–593. Danso, S. K. A. & M. Alexander, 1975. Regulation of predation by prey density: the protozoan-Rhizobium relationship. Appl. envir. Microbiol. 29: 515–521. Edwards, R. T., 1987. Sestonic bacteria as a food source for filtering invertebrates in two southeastern blackwater rivers. Limnol. Oceanogr. 32: 221–234. Edwards, R. T. & J. L. Meyer, 1987. Metabolism of a subtropical low gradient blackwater river. Freshwat. Biol. 17: 251–263. Fenchel, T., 1982. Ecology of heterotrophic microflagellates. IV. Quantitative occurrence and importance as bacterial consumers. Mar. Ecol. Prog. Ser. 9: 35–42. Fenchel, T., 1986. Ecology of protozoa, the biology of freeliving protists. Springer-Verlag, N.Y., 197 p. Findlay, S., J. L. Meyer & R. Risley, 1986. Benthic bacterial biomass and production in two blackwater rivers. Can. J. Fish. aquat. Sci. 43: 1271–1276. Gilroy, D., 1975. The determination of the rate constants of island colonization. Ecology 56: 915–923. Hrbacek, J., 1977. Competition and predation in relation to species composition of freshwater zooplankton, mainly Cladocera. In J. Cairns (ed.), Aquatic Microbial Communities. Garland Publ. Inc. N.Y.: 305–353. Madoni, P. & P. F. Ghetti, 1981. The structure of ciliated protozoan communities in biological sewage treatment plants. Hydrobiologia 83: 207–215. Meyer, J. L., 1986. Dissolved organic carbon dynamics in two subtropical blackwater rivers. Arch. Hydrobiol. 108: 119–134. Meyer, J. L., R. T. Edwards & R. Risley, 1987. Bacterial growth on dissolved organic carbon from a blackwater river. Microb. Ecol. 13: 13–29. Patrick, R., M. H. Hohn & J. H. Wallace, 1954. A new method for determining the pattern of diatom flora. Not. Nat. Acad. Nat. Sci. Phil. 259: 1–12. Pratt, J. R., B. Z. Lang, R. L. Kaesler & J. Cairns Jr., 1986. Effect of seasonal changes on protozoans inhabiting artificial substrates in a small pond. Arch. Protistenkd. 131: 45–57. Preston, F. W., 1948. The commonness, and rarity of species. Ecology 29: 254–283. Sieburth, J. McN., V. Smetacek & J. Lenz, 1978. Pelagic ecosystem structure: Heterotrophic compartments of the plankton and their relationship to plankton size fractions. Limnol. Oceanogr. 23: 1256–1263. Sorokin, Y. I., 1981. Microheterotrophic organisms in marine ecosystems. In A. R. Longhurst (ed.), Analysis of Marine Ecosystems. Academic Press, N.Y.: 293–342. Taylor, W. D. & J. Berger, 1980. Microspatial heterogeneity in the distribution of ciliates in a small pond. Microb. Ecol. 6: 27–34. Wallace, J. B. & A. C. Benke, 1984. Quantification of wood habitat in subtropical coastal plain streams. Can. J. Fish. aquat. Sci. 41: 1643–1652. Wang, C. C., 1928. Ecological studies of the seasonal distribution of protozoa in a freshwater pond. J. Morph. 46: 431–478.