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Biodiversity & Conservation

, Volume 7, Issue 4, pp 419–433 | Cite as

The influence of the Benguela upwelling system on Namibia's marine biodiversity

  • A.L. Sakko
Article

Abstract

Namibia's marine environment falls within the Benguela system, an eastern boundary current upwelling system in the south eastern Atlantic Ocean. Conditions within much of this environment change continuously as a consequence of the upwelling of nutrient-rich water into the surface zone. In addition, irregular anomalies in temperature, oxygen concentration and salinity occur, particularly in shelf waters. These fluctuations, which are inherent in the functioning of the Benguela system, tend to favour the persistence of few, generalist species, while at the same time high productivity supports large abundances. This trend is evident in all the major marine habitats off Namibia, where diversity is often lower than in comparable habitats in the southern Benguela system off the west coast of South Africa. Namibia's marine environment is considered 'relatively pristine', although threats to biodiversity are posed by both natural and anthropogenic phenomena.

marine biodiversity Benguela upwelling Namibia 

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References

  1. Angel, M.V. (1993) Biodiversity of the pelagic ocean. Conserv. Biol. 7, 771.Google Scholar
  2. Angel, M.V. (1995) Biodiversity of the deep ocean. Biological Diversity in Tropical Marine Environments: Reviews Contributing to the Conservation of Aquatic Biodiversity and its Sustainable Use by Tropical Developing Countries. London: Overseas Development Administration of the United Kingdom of Great Britain and Northern Ireland.Google Scholar
  3. Anon. (1996) Survey of the offshore and inshore horse mackerel stocks of Namibia. Surveys of the Fish Resources of Namibia. Preliminary report, cruise 3/96 of the research vessel Dr Fridtjof Nansen.Google Scholar
  4. Bally, R. (1983) Intertidal zonation on sandy beaches of the west coast of South Africa. Cahiers Biol. Marine (Paris) 24, 85–103.Google Scholar
  5. Barnes, R.S.K. and Hughes, R.N. (1988) An Introduction to Marine Biology, 2nd edn. London: Blackwell Scientific Publications.Google Scholar
  6. Berruti, A. (1989) Resident seabirds. In Oceans of Life Off Southern Africa(A.I.L. Payne and R.J.M. Crawford, eds) pp. 257–73. Cape Town: Vlaeberg Publishers.Google Scholar
  7. Best, P.B. and Ross, G.J.B. (1989) Whales and whaling. In Oceans of Life Off Southern Africa (A.I.L. Payne and R.J.M. Crawford, eds) pp. 315–38. Cape Town: Vlaeberg Publishers.Google Scholar
  8. Beyers, C.J. de B. (1994) Population size and density of the deep-sea red crab Chaceon maritae (Manning and Holthuis) off Namibia determined from tag-recapture. S. Afr. J. Mar. Sci. 14, 1–9.Google Scholar
  9. Bianchi, G., Carpenter, K.E., Roux, J-P., Molloy, F.J., Boyer, D. and Boyer, H. (1993) The Living Marine Resources of Namibia. Rome: FAO.Google Scholar
  10. Bolton, J.J. and Anderson, R.S. (1997) Marine vegetation. In Vegetation of Southern Africa (R.M. Cowling, D.M. Richardson and S.M. Pierce, eds) pp. 348–70. Cambridge: Cambridge University Press.Google Scholar
  11. Boyd, A.J., Hewitson, J.D., Kruger, I. and Le Clus, F. (1985) Temperature and salinity trends off Namibia from August 1982 to August 1984 and their relation to plankton abundance and the reproductive success of pelagic fish. ICSEAF Collection of Scientific Papers 1, 53–8.Google Scholar
  12. Boyd, A.J. and Thomas, R.M. (1984) A southward intrusion of equatorial water off northern and central Namibia in March 1984. Trop. Ocean-Atmosphere Newslett. 27, 16–7.Google Scholar
  13. Boyer, D.C., Goosen, A.C., Boyer, H.J. and Coetzee, J.C. (1997) Analysis of the 1990 and 1991 Namibian pelagic fishing seasons. Madoqua (in press).Google Scholar
  14. Brown, J.H. (1984) On the relationship between abundance and distribution of species. Amr. Natur. 124, 255–79.Google Scholar
  15. Bustamante, R.H., Branch, G.M., Velasquez, C.R. and Branch, M. (1993) Intertidal survey of the rocky shores at the Elizabeth Bay area (Sperrgebiet, Namibia). Consultancy report. Windhoek: Consolidated Diamond Mines.Google Scholar
  16. Carola, M. (1994) Checklist of the marine planktonic copepoda of southern Africa and their worldwide geographic distribution. S. Afr. J. Mar. Sci. 14, 225–53.Google Scholar
  17. Chapman, P. and Shannon, L.V. (1985) The Benguela ecosystem. Part II. Chemistry and related processes. Oceanogr. Mar. Biol. Ann. Rev. 23, 183–251.Google Scholar
  18. Clarke, A. (1992) Is there a latitudinal diversity cline in the sea? Trends Ecol. Evol. 7, 286–7.Google Scholar
  19. Copenhagen, W.J. (1953) The periodic mortality of fish in the Walvis region. A phenomenon within the Benguela Current. Investig. Rep. Div. Sea Fish. S. Afr. 14, 1–35.Google Scholar
  20. Crawford, R.J.M. and Shelton, P.A. (1981) Population trends for some southern African seabirds related to fish availability. In Proceedings of the Symposium on Birds of the Sea and Shore, 1979 (J. Cooper, ed.) pp. 15–41. Cape Town: African Seabird Group.Google Scholar
  21. Crawford, R.J.M., Shannon, L.V. and Pollock, D.E. (1987) The Benguela ecosystem. Part IV. The major fish and invertebrate resources. Oceanogr. Mar. Biol. Ann. Rev. 25, 353–505.Google Scholar
  22. David, J.H.M. (1989) Seals. In Oceans of Life Off Southern Africa (A.I.L. Payne and R.J.M. Crawford, eds) pp. 288–302. Cape Town: Vlaeberg Publishers.Google Scholar
  23. Donn, T.E. Jr. and Cockroft, A.C. (1989) Macrofaunal community structure and zonation of two sandy beaches on the central Namib coast, South West Africa/Namibia. Madoqua 16, 129–35.Google Scholar
  24. Emanuel, B.P., Bustamante, R.H., Branch, G.M., Eekhout, S. and Odendaal, F.J. (1992) A zoo-geographic and functional approach to the selection of marine reserves on the west coast of South Africa. S. Afr. J. Mar. Sci. 12, 341–54.Google Scholar
  25. Engledow, H.E. and Bolton, J.J. (1994) Seaweed alpha-diversity within the lower eulittoral zone in Namibia: the effects of wave action, sand inundation, mussels and limpets. Bot. Mar. 37, 267–76.Google Scholar
  26. Engledow, H.E., Bolton, J.J. and Stegenga, H. (1992) The biogeography of the seaweed flora of Namibia. In Proceedings of the First Workshop on Sustainable Seaweed Resource Development in sub-Saharan Africa (K.E. Mshigeni, J.J. Bolton, A.T. Critchley and G. Kiangi, eds) pp. 117–30. Windhoek: K.E. Mshigeni, University of Namibia.Google Scholar
  27. Estrada, M. and Marrase, C. (1987) Phytoplankton biomass and productivity off the Namibian coast. S. Afr. J. Mar. Sci. 5, 347–56.Google Scholar
  28. Gaudian, G. and Medley, P.A.H. (1995) Coastal marine biological diversity. Biological Diversity in Tropical Marine Environments: Reviews Contributing to the Conservation of Aquatic Biodiversity and its Sustainable Use by Tropical Developing Countries. London: Overseas Development Administration of the United Kingdom of Great Britain and Northern Ireland.Google Scholar
  29. Griffin, M. (1998) The species diversity, distribution and conservation of Namibian mammals. Biodiv. Conserv. 7, 483.Google Scholar
  30. Hart, T.J. and Currie, R.I. (1960) The Benguela current. Discovery Rep. 31, 123–298.Google Scholar
  31. Hockey, P.A.R. and Van Erkom Schurink, C. (1992) The invasive biology of the mussel Mytilus galloprovincionalis in southern Africa. Trans. Roy. Soc. S. Afr. 48, 123–39.Google Scholar
  32. Kensley, B. and Penrith, M-L. (1980) The constitution of the intertidal fauna of rocky shores of South West Africa. Part III. The north coast from False Cape Frio to the Kunene River. Cimbebasia Ser A 5, 201–14.Google Scholar
  33. Kruger, I. (1980) A checklist of South West African marine phytoplankton, with some phytogeographical relations. Fisheries Bull. S. Afr. 13, 31–53.Google Scholar
  34. Kruger, I. and Boyd, A.J. (1984) Investigation into the hydrology and plankton at the surface waters off southwestern Africa in ICSEAF Divisions 1.3, 1.4 and 1.5 in 1982/83. ICSEAF Collection of Scientific Papers 11, 109–34.Google Scholar
  35. Lawson, G.W., Simons, R.H. and Isaac, W.E. (1990) The marine algal flora of Namibia. Bull. Brit. Mus. Nat. Hist. (Bot.) 20, 153–68.Google Scholar
  36. Le Clus, F. (1985) Effects of a warm water intrusion on the anchovy fishery in Namibia. ICSEAF Collection of Scientific Papers 12, 99–101.Google Scholar
  37. Le Clus, F., Hewitson, J.D., Melo, Y.C., Cooper, R.M. and Malan, P.E. (1987) The multi-species pelagic fishery off Namibia 1982-1986 and stock assessments for pilchard and anchovy. ICSEAF Collection of Scientific Papers 14, 7–15.Google Scholar
  38. Lenssen, J., Tarr, P. and Berry, H. (1991) An assessment of visitor statistics and linefishing along the Sandwich shoreline, Namib-Naukluft Park, Namibia. Madoqua 18, 33–6.Google Scholar
  39. Lewis, R.I. and Beardmore, J.A. (1995) Genetics and biodiversity in tropical freshwater, estuarine, coastal and deep sea environments. Biological Diversity in Tropical Marine Environments: Re-views Contributing to the Conservation of Aquatic Biodiversity and Sustainable Use by Tropical Developing Countries. London: Overseas Development Administration of the United Kingdom of Great Britain and Northern Ireland.Google Scholar
  40. Lleonart, J. and Roel, B. (1984) Analisis de las comunidades de peces y crustaceos demersales de la costa de Namibia (Atlantico Sudoriental). Investigacion Pesqueras (Barcelona) 48, 187–206.Google Scholar
  41. Macpherson, E. and Roel, B.A. (1987) Trophic relationships in the demersal fish community off Namibia. S. Afr. J. Mar. Sci. 5, 585–96.Google Scholar
  42. Mas-Riera, J., Lombarte, A., Gordoa, A. and Macpherson, E. (1990) Influence of Benguela upwelling on the structure of demersal fish populations off Namibia. Mar. Biol. 104, 175–82.Google Scholar
  43. McLachlan, A. (1985) The ecology of two sandy beaches near Walvis Bay. Madoqua 14, 155–63.Google Scholar
  44. McNaughton, S.J. and Wolf, L.L. (1970) Dominance and the niche in ecological systems. Science 167, 131–9.Google Scholar
  45. MFMR (1996) Economic performance by fishery. Internal memorandum. Windhoek: Ministry of Fisheries and Marine Resources.Google Scholar
  46. Moldan, A.G.S. (1989) Marine pollution. In Oceans of Life Off Southern Africa (A.I.L. Payne and R.J.M. Crawford, eds) pp. 41–9. Cape Town: Vlaeberg Publishers.Google Scholar
  47. O'Toole, M.J. and Bartholomae, C. (1995) An overview of marine environmental conditions off Namibia during 1994-1995. Proceedings of Annual Research Meeting, February 1995. Windhoek: Ministry of Fisheries and Marine Resources.Google Scholar
  48. Penrith, M.J. and Kensley, B.F. (1970) The constitution of the intertidal fauna of rocky shores of South West Africa 1: Lüderitzbucht. Cimbebasia A(1) 9, 191–239.Google Scholar
  49. Pillar, S.C. and Hutchings, L. (1989) Plankton. In Oceans of Life Off Southern Africa (A.I.L. Payne and R.J.M. Crawford, eds) pp. 28–40. Cape Town: Vlaeberg Publishers.Google Scholar
  50. Rex, M.A., Stuart, C.T., Hessler, R.R., Allen, J.A., Sanders, H.L. and Wilson, G.K.F. (1993) Global-scale latitudinal patterns of species diversity in the deep-sea benthos. Nature 365, 636–9.Google Scholar
  51. Roel, B.A., Rucabado, J., Lloris, D. and Lleonart, J. (1985) Las comunidades de peces demersales del afloramiento de Africa occidental (Sahara y Namibia). In Simposio internacional sobre las areas de afloramiento mais importantes del oueste africano (Cabo Blanco y Benguela) (C. Bas, R. Margalef, and P. Rubies, eds) pp. 691–700. Barcelona: Instituto Investigaciones Pesqueras.Google Scholar
  52. Rogers, J. and Bremner, J.M. (1991) The Benguela ecosystem. Part VII. Marine-geological aspects. Oceanogr. Mar. Biol. Ann. Rev. 29, 1–85.Google Scholar
  53. Ross, G.J.B. and Best, P.B. (1989) Smaller whales and dolphins. In Oceans of Life Off Southern Africa (A.I.L. Payne and R.J.M. Crawford, eds) pp. 303–14. Cape Town: Vlaeberg Publishers.Google Scholar
  54. Sanders, H.L. (1968) Marine benthic diversity: a comparative study. Am. Natur. 102, 243–82.Google Scholar
  55. Shackleton, L.Y. (1987) A comparative study of fossil fish scales from three upwelling regions. S. Afr. J. Mar. Sci. 5, 79–84.Google Scholar
  56. Shackleton, L.Y. (1988) Fossil pilchard and anchovy scales-indicators of past fish populations off Namibia. Proceedings of the International Symposium on Long Term Changes in Fish Populations, 1986, pp. 55–68. Vigo.Google Scholar
  57. Shannon, L.V. (1985) The Benguela ecosystem. Part I. Evolution of the Benguela, physical features and processes. Oceanogr. Mar. Biol. Ann. Rev. 23, 105–82.Google Scholar
  58. Shannon, L.V. (1989) The physical environment. In Oceans of Life Off Southern Africa (A.I.L. Payne and R.J.M. Crawford, eds) pp. 12–27. Cape Town: Vlaeberg Publishers.Google Scholar
  59. Shannon, L.V. and Pillar, S.C. (1986) The Benguela ecosystem. Part III. Plankton. Oceanogr. Mar. Biol. Ann. Rev. 24, 65–170.Google Scholar
  60. Shannon, L.V., Boyd, A.J., Brundrit, G.B. and Taunton-Clark, J. (1986) On the existence of an El-Niño type phenomenon in the Benguela System. J. Mar. Res. 44, 495–520.Google Scholar
  61. Shannon, L.V., Agenbag, J.J. and Buys, M.E.L. (1987) Large-and meso-scale features of the Angola-Benguela front. S. Afr. J. Mar. Sci. 5, 11–34.Google Scholar
  62. Stander, G.H. and De Decker, A.H.B. (1969) Some physical and biological aspects of an oceanographic anomaly off South West Africa in 1963. Investig. Rep. Marine Res. Lab. S. W. Afr. 13, 1–35.Google Scholar
  63. Stegenga, H., Bolton, J.J. and Anderson, R.J. (1997) Seaweeds of the South African west coast. Contrib. Bolus Herb. (in press).Google Scholar
  64. Stephenson, T.A. and Stephenson, A. (1972) Life Between Tidemarks on Rocky Shores. San Francisco: W.H. Freeman and Co.Google Scholar
  65. Tarr, J.G., Griffiths, C.L. and Bally, R. (1985) The ecology of three sandy beaches on the Skeleton Coast of South West Africa. Madoqua 14, 295–304.Google Scholar

Copyright information

© Chapman and Hall 1998

Authors and Affiliations

  • A.L. Sakko
    • 1
  1. 1.Vineta, SwakopmundNamibia

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