Journal of Paleolimnology

, Volume 23, Issue 4, pp 373–383 | Cite as

A 12,400 14c yr Offshore Diatom Record From East Central Lake Victoria, East Africa

  • J.C. Stager
  • T.C. Johnson
Article

Abstract

The diatom record of V95-2P, a 7.6 m long sediment core collected from 67 m depth, is the first from the east central portion of Lake Victoria. A soil horizon developed at the coring site shortly before 12,400 14C yr BP due to a lakewide desiccation event. The radiocarbon chronology of the older half of this core is problematic, but if our estimated chronology is correct, then aridity and evaporative concentration of the lake are indicated by the presence of Thalassiosira rudolfi from > 12,400 BP to about 10,000 BP. Abundant Aulacoseira and generally rising biogenic silica concentrations may reflect enhanced water column mixing and rising precipitation:evaporation ratios ca. 10,000-8400 BP. A lakewide reorganization of diatom assemblages occurred around 7200 BP, when Aulacoseira nyassensis largely replaced A. granulata and after which rainfall and wind-driven mixing became more seasonally restricted. Pronounced reductions in offshore diatom deposition, from about 8300-5800 BP and after 3500 BP, may have been related to declines in the duration and/or intensity of wind-driven mixing. Increased aridity, and possibly deforestation in the lake basin, is indicated after 1400 BP.

Africa biogenic silica climate diatoms Lake Victoria monsoons phytoliths pollen 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bard, E., F. Rostek & C. Sonzogni, 1997. Interhemisphericsynchrony of the last deglaciation inferred from alkenonepalaeothermometry. Nature 385: 707–710.Google Scholar
  2. Beuning, K., K. Kelts & T. C. Johnson, 1997. Paleohydrology of Lake Victoria, East Africa, inferred from 18O/16O ratios in sediment cellulose. Geology 25: 1083–1086.Google Scholar
  3. Bolick, M. R., 1991. A vegetational history of the Mt. Ujamaa lahar, Tanzania. Palynology 15: 193–210.Google Scholar
  4. Butzer, K. W., G. L. Isaac, J. L. Richardson & C. K. Washbourn-Kamau, 1972. Radiocarbon dating of East African lake levels. Science 175: 1069–1076.Google Scholar
  5. Caljon, A. G. & C. Z. Cocquyt, 1992. Diatoms from surface sediments of the northern part of Lake Tanganyika. Hydrobiologia 230: 135–156.Google Scholar
  6. Cohen, A. S. & C. Nielsen, 1986. Ostracodes as indicators of paleohydrochemistry in lakes: a late Quaternary example from Lake Elmenteita, Kenya. Palaios 1: 601–609.Google Scholar
  7. Crul, R. C. M., 1995. Limnology and hydrology of Lake Victoria. UNESCO/IHP-IV Project M-5.1. UNESCO Publishing.Google Scholar
  8. Demaster, D. J., 1979. The marine budgets of silica and Si32. Doctoral dissertation. Yale University.Google Scholar
  9. Finney, B. P. & T. C. Johnson, 1991. Sedimentation in lake Malawi (East Africa) during the past 10,000 years: a continuous paleoclimatic record from the southern tropics. Palaeogeogr. Palaeoclim. Palaeoecol. 85: 351–366.Google Scholar
  10. Gasse, F., 1986. East African diatoms: Taxonomy, ecological distribution. Bibl. Diatomol., Band 11. J. Cramer, Stuttgart.Google Scholar
  11. Gasse, F., 1987. Diatoms for reconstructing palaeoenvironments and paleohydrology in tropical semi-arid zones. Hydrobiologia 154: 127–163.Google Scholar
  12. Gasse, F., V. Ledee, M. Massault & J.-C. Fontes, 1989. Water-level fluctuations of Lake Tanganyika in phase with oceanic changes during the last glaciation and deglaciation. Nature 342: 57–59.Google Scholar
  13. Gasse, F., S. Juggins & L. Ben Khelifa, 1995. Diatom-based transfer functions for inferring past hydrochemical characteristics of African Lakes. Paleogeogr. Palaeoclim. Palaeoecol. 117: 31–54.Google Scholar
  14. Gillespie, R., F. A. Street-Perrott & R. Switsur, 1983. Post-glacial arid episodes in Ethiopia have implications for climate prediction. Nature 306: 680–682.Google Scholar
  15. Giresse, P., J. Maley & P. Brenac, 1994. Late Quaternary palaeoenvironments in the Lake Barombi Mbo (West Cameroon) deduced from pollen and carbon isotopes of organic matter. Palaeogeogr. Palaeoclim. Palaeoecol. 107: 65–78.Google Scholar
  16. Haberyan, K. A. & R. E. Hecky, 1987. The late Pleistocene stratigraphy and paleolimnology of Lakes Kivu and Tanganyika. Palaeogeogr. Palaeoclim. Palaeoecol. 61: 169–197.Google Scholar
  17. Haberyan, K. A. & O. K. Mhone, 1991. Algal communities near Cape Maclear, southern Lake Malawi, Africa. Hydrobiologia 215: 175–188.Google Scholar
  18. Haworth, E. Y., 1977. The sediments of Lake George (Uganda). V. The diatom assemblages in relation to the ecological history. Arch. Hydrobiol. 80: 200–215.Google Scholar
  19. Hecky, R. E., 1993. The eutrophication of Lake Victoria. Verh. Internat. Verein. Limnol. 25: 39–48.Google Scholar
  20. Hecky, R. E. & P. Kilham, 1973. Diatoms in alkaline, saline lakes: ecology and geochemical implications. Limnol. Oceanogr. 18: 52–71.Google Scholar
  21. Hustedt, F., 1949. S-usswasser Diatomeen aus dem Albert-National Park und Belgische-Kongo. Expl. du Parc Nat. Albert, Miss. H. Damas (1935–1936) 8: 1–199.Google Scholar
  22. Johnson, T. C., C. A. Scholz, M. R. Talbot, K. Kelts, G. Ngobi, K. Beuning, I. Ssemmanda & J. A. McGill, 1996. Late Pleistocene desiccation of Lake Victoria and rapid evolution of cichlid fishes. Science 273: 1091–1093.Google Scholar
  23. Johnson, T. C., Y. Chan, K. Beuning, K. Kelts, G. Ngobi & D. Verschuren, 1998. Biogenic silica profiles in Holocene cores from Lake Victoria: Implications for lake level history and initiation of the Victoria Nile. In Lehman, J. T. (ed.), Environmental Change and Response in East African Lakes. Kluwer, Dordrecht, 75–88.Google Scholar
  24. Jolly, D., R. Bonnefille & M. Roux, 1994. Numerical interpretation of a high resolution Holocene pollen record from Burundi. Palaeogeogr. Palaeoclim. Palaeoecol. 109: 357–370.Google Scholar
  25. Kendall, R. L., 1969. An ecological history of the Lake Victoria basin. Ecol. Monogr. 39: 121–176.Google Scholar
  26. Kilham, P. & S. S. Kilham, 1975. Melosira granulata (Ehr.) Ralfs: morphology and ecology of a cosmopolitan freshwater diatom. Verh. Internat. Verein. Limnol. 19: 2716–2721.Google Scholar
  27. Kilham, P., S. S. Kilham & R. E. Hecky, 1986. Hypothesized resource relationships among African planktonic diatoms. Limnol. Oceanogr. 31: 1169–1181.Google Scholar
  28. Kramer, K. & H. Lange-Bertalot. 1991. Suesswasserflora von Mitteleuropa. 3 Teil: Centrales, Fragilariaceae, Eunotiaceae. Fischer Verlag, Stuttgart.Google Scholar
  29. Krause, G. L., C. L. Schelske & C. O. Davis, 1983. Comparison of three wet-alkaline methods of digestion of biogenic silicain water. Freshwat. Biol. 13: 73–81.Google Scholar
  30. Maley, J., 1982. Dust, clouds, rain types and climatic variations in tropical North Africa. Quat. Res. 18: 1–16.Google Scholar
  31. Mayewski, P. A., L. D. Meeker, M. S. Twickler, S. I. Whitlow, Q. Yang & M. Prentice, 1997. Major features and forcing of high-latitude northern hemisphere atmospheric circulation over the last 110,000 years. J. Geophys. Res. 102: 26,345–26,366.Google Scholar
  32. Nicholson, S. E. & H. Flohn, 1980. African environmental and climatic changes and the general atmospheric circulation in late Pleistocene and Holocene. Clim. Change 2: 313–348.Google Scholar
  33. Ochumba, P. B. O. & D. I. Kibaara, 1989. Observations on bluegreen algal blooms in the open waters of Lake Victoria, Kenya. Afr. J. Ecol. 27: 23–34.Google Scholar
  34. Patrick, R. & C. W. Reimer, 1966. The diatoms of the United States. Vol. 1, Monogr. Acad. Nat. Sci. Philadelphia.Google Scholar
  35. Pokras, E. M. & A. C. Mix, 1985. Eolian evidence for spatial variability of late Quaternary climates in tropical Africa. Quat. Res. 24: 137–149.Google Scholar
  36. Richardson, J. L. & R. A. Dussinger, 1986. Paleolimnology of midelevation lakes in the Kenya Rift Valley. Hydrobiologia 143: 167–174.Google Scholar
  37. Sirocko, F., M. Sarntheim, H. Erlenkeuser, H. Lange, M. Arnold & J. C. Duplessy, 1993. Century-scale events in monsoonal climate over the past 24,000 years. Nature 364: 322–324.Google Scholar
  38. Sirocko, F., D. Garbe-Schönberg, A. McIntyre & B. Molfino, 1996. Teleconnections between the subtropical monsoons and highlatitude climates during the last deglaciation. Science 272: 526–529.Google Scholar
  39. Stager, J. C., 1984. The diatom record of Lake Victoria (East Africa): the last 17,000 years. In Mann, D. G. (ed.), Proc. Seventh Internat. Diatom Symp., Philadelphia. Strauss &Cramer, Koenigstein: 455–476.Google Scholar
  40. Stager, J. C., 1988. Environmental changes at Lake Cheshi, Zambia since 40,000 years B.P. Quat. Res. 29: 54–65.Google Scholar
  41. Stager, J. C., P. R. Reinthal & D. A. Livingstone, 1986. A 25,000 year history for Lake Victoria, East Africa, and some comments on its significance for the evolution of cichlid fishes. Freshwat. Biol. 16: 15–19.Google Scholar
  42. Stager, J. C., B. Cumming & L. D Meeker, 1997. An 11,400-year, high-resolution diatom record from Lake Victoria, East Africa. Quat. Res. 47: 81–89.Google Scholar
  43. Stager, J. C. & P. A. Mayewski, 1997. Abrupt early to mid-Holocene climatic transition registered at the equator and the poles. Science 276: 1834–1836.Google Scholar
  44. Street-Perrott, F. A. & N. Roberts, 1983. Fluctuations in closedbasin lakes as an indicator of past atmospheric circulation patterns. pp. 331–345. In Street-Perrott, A. et al. (eds), Variations in the Global Water Budget. Reidel, Dordrecht.Google Scholar
  45. Stuiver, M., 1970. Long-term C14 variations. In Olsson, I. U. (ed.) Radiocarbon Variations and Absolute Chronology. Proc. 12th Nobel Symp., Uppsala. John Wiley & Sons, N.Y.: 197–213.Google Scholar
  46. Talbot, M. R. & T. Laerdal, 1996. First isotopic and pyrolysis data is in from Victoria 2P core. IDEAL Bull. (Spring): 1–2.Google Scholar
  47. Talling, J. F., 1966. The annual cycle of stratification and phytoplankton growth in Lake Victoria (East Africa). Int. Rev. Ges. Hydrobiol. 51: 545–621.Google Scholar
  48. Taylor, D. M., 1990. Late Quaternary pollen records from two Ugandan mires: evidence for environmental change in the Rukiga Highlands of southwest Uganda. Palaeogeogr. Palaeoclim. Palaeoecol. 80: 283–300.Google Scholar
  49. Temple, P. H. 1964. Evidence of lake-level changes from the northern shoreline of Lake Victoria, Uganda. In Steel, R. W. & R. M. Prothero (eds.), Geographers and the Tropics: Liverpool Essays. Longman, London, 31–56.Google Scholar
  50. Vincens, A., F. Chalié & R. Bonnefille, 1993. Pollen-derived rainfall and temperature estimates from Lake Tanganyika and their implication for late Pleistocene water levels. Quat. Res. 40: 343–350.Google Scholar
  51. Yin, X. & S. E. Nicholson, (in press). The water balance of Lake Victoria. Hydrol. Sci. J.Google Scholar

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • J.C. Stager
    • 1
  • T.C. Johnson
    • 2
  1. 1.Math/Science DivisionPaul Smith's College, Paul SmithsUSA
  2. 2.Large Lakes ObservatoryUniversity of MinnesotaDuluthUSA

Personalised recommendations