Biological Invasions

, Volume 11, Issue 4, pp 801–812 | Cite as

Potential spread of the invasive plant Hydrilla verticillata in South Africa based on anthropogenic spread and climate suitability

  • Julie A. Coetzee
  • Martin P. Hill
  • Dieter Schlange
Original Paper


Hydrilla verticillata (L.f.) Royle is a submerged aquatic plant native to Asia and Australia that is highly invasive in the USA and was first recorded in South Africa in 2006. It is only known from one locality, Pongolapoort Dam in KwaZulu-Natal Province, but there are fears that it might spread to other sites. The primary vector of spread in the USA is recreational boaters and anglers. A survey at a fishing competition on Pongolapoort Dam showed that anglers travel considerable distances around South Africa (73% of water bodies were >200 km, visited by 68% of the respondents). A Threat Index for freshwater bodies throughout South Africa visited by participants of the competition was calculated showing that dams in the vicinity of the infestation were more at risk from invasion. Further, the potential distribution of the weed based on climatic matching with the region of origin showed that most of the country was suitable for establishment, with the exception of the high-lying interior of the country. Recommendations for reducing the potential spread of hydrilla in South Africa are presented.


Climate-based distribution modeling Anglers Hydrilla Vectors of spread Integrated management 



The authors thank the students from the University of the Witwatersrand who conducted the questionnaires with the anglers, in particular, Luke Schutz, Taryn Morris and Christopher Barichievy. The Invasive Alien Species Programme of the KwaZulu-Natal Department of Agricultural and Environmental Affairs, South Africa is acknowledged for funding aspects of this study.


  1. Balciunas JK, Grodowitz MJ, Cofrancesco AF, Shearer JF (2002) Hydrilla. In: van Driesche RG, Lyon S, Blossey B, Hoddle MS, Reardon R (eds) Biological control of invasive plants in the eastern United States. USDA Forest Service, Morgantown, pp 91–114Google Scholar
  2. Bell-Cross G, Minshull JL (1988) The fishes of Zimbabwe. National Museums and Monuments of Zimbabwe, HarareGoogle Scholar
  3. Blackburn RD, Weldon RW, Yeo RR, Taylor TM (1969) Identification and distribution of certain similar-appearing submersed aquatic weeds in Florida. Hyacinth Control J 8(1):17–21Google Scholar
  4. Buchan LAJ, Padilla DK (1999) Estimating the probability of long-distance overland dispersal of invading aquatic species. Ecol Appl 9:254–265. doi: 10.1890/1051-0761(1999)009[0254:ETPOLD]2.0.CO;2 CrossRefGoogle Scholar
  5. Center TD, Frank JH, Dray FA (1997) Biological control. In: Simberloff D, Schmitz DC, Brown TC (eds) Strangers in paradise. Impact and management of nonindigenous species in Florida. Island Press, Washington, pp 245–266Google Scholar
  6. Coetzee JA (2006) The threat of hydrilla to South Africa. Plant Prot News 68:15Google Scholar
  7. Cook CDK, Lüönd R (1982) A revision of the genus hydrilla (Hydrocharitaceae). Aquat Bot 13:485–504. doi: 10.1016/0304-3770(82)90074-2 CrossRefGoogle Scholar
  8. Floerl O, Inglis GJ (2005) Starting the invasion pathway: the interaction between source populations and human transport vectors. Biol Invasions 7:589–606. doi: 10.1007/s10530-004-0952-8 CrossRefGoogle Scholar
  9. Haller WT (1982) Hydrilla goes to Washington. Aquatics 4(4):6–7Google Scholar
  10. Henderson JE, Kirk JP, Lamprecht SD, Hayes WE (2003) Economic impacts of aquatic vegetation to angling in two South Carolina reservoirs. J Aquat Plant Manage 41:53–56Google Scholar
  11. Hengeveld R (1994) Small-step invasion research. Trends Ecol Evol 9:339–342. doi: 10.1016/0169-5347(94)90155-4 CrossRefGoogle Scholar
  12. Hill MP (2003) The impact and control of alien aquatic vegetation in South African aquatic ecosystems. Afr J Aquat Sci 28:19–24Google Scholar
  13. Hoyer MV, Netherland MD, Allen MS, Canfield DE Jr (2005) Hydrilla management in Florida: a summary and discussion of issues identified by professionals with future management recommendations. Florida LAKEWATCH, Department of Fisheries and Aquatic Sciences, University of Florida/IFASGoogle Scholar
  14. Johnson LE, Ricciardi A, Carlton JT (2001) Overland dispersal of aquatic invasive species: a risk assessment of transient recreational boating. Ecol Appl 11:1789–1799. doi: 10.1890/1051-0761(2001)011[1789:ODOAIS]2.0.CO;2 CrossRefGoogle Scholar
  15. Johnstone IM, Coffey BT, Howard-Williams C (1985) The role of recreational boat traffic in interlake dispersal of macrophytes: a New Zealand case study. J Environ Manage 20:263–279Google Scholar
  16. Kolar CS, Lodge DM (2002) Ecological predictions and risk assessment for alien fishes in North America. Science 298:1233–1236. doi: 10.1126/science.1075753 PubMedCrossRefGoogle Scholar
  17. Langeland KA (1990) Hydrilla (Hydrilla verticillata (L.f.) Royle): a continuing problem in Florida waters. University of Florida Coop. Extension Service Circular No. 884. University of Florida. Gainesville, FloridaGoogle Scholar
  18. Langeland KA (1996) Hydrilla verticillata (L.F.) Royle (Hydrocharitaceae), “The perfect aquatic weed”. Castanea 61:293–304Google Scholar
  19. Leung B, Bossenbroek JM, Lodge DM (2006) Boats, pathways, and aquatic biological invasions: estimating dispersal potential with gravity models. Biol Invasions 8:241–254. doi: 10.1007/s10530-004-5573-8 CrossRefGoogle Scholar
  20. Lodge DM, Stein RA, Brown KM, Covich AP, Brönmark C, Garvey JE et al (1998) Predicting impact of freshwater exotic species on native biodiversity: challenges in spatial scaling. Aust J Ecol 23:53–67. doi: 10.1111/j.1442-9993.1998.tb00705.x CrossRefGoogle Scholar
  21. Maceina MJ, Reeves WC (1996) Relations between submersed macrophyte abundance and largemouth bass tournament success on two Tennessee River impoundments. J Aquat Plant Manage 34:33–38Google Scholar
  22. Madeira PT, Coetzee JA, Center TD, White EE, Tipping PW (2007) The origin of Hydrilla verticillata recently discovered at a South African dam. Aquat Bot 87:176–180. doi: 10.1016/j.aquabot.2007.04.008 CrossRefGoogle Scholar
  23. Mahler MJ (1979) Hydrilla the number one problem. Aquatics 1:56Google Scholar
  24. Muirhead JR, MacIsaac HJ (2005) Development of inland lakes as hubs in an invasion network. J Appl Ecol 42:80–90. doi: 10.1111/j.1365-2664.2004.00988.x CrossRefGoogle Scholar
  25. Noble RG, Hemens J (1978) Inland water ecosystems in South Africa—a review of research needs. South African National Scientific programmes report no. 34. 150 ppGoogle Scholar
  26. Schmitz DC, Nelson BV, Nall LE, Schardt JD (1991) Exotic aquatic plants in Florida: a historical perspective and review of present aquatic plant regulation program. In: Center TD, Doren RF, Hofstetter RL, Myers RL, Whiteaker LD (eds) Proceedings of a symposium on exotic pest plants, November 2–4, 1988, Miami, Florida. United States Department of the Interior, National Park Service, Washington, D.C., pp 303–336Google Scholar
  27. Schooler S, Julien M, Walsh GC (2006) Predicting the response of Cabomba caroliniana populations to biological control agent damage. Aust J Entomol 45:327–330. doi: 10.1111/j.1440-6055.2006.00559.x CrossRefGoogle Scholar
  28. Skelton P (2001) A complete guide to the freshwater fishes of Southern Africa. Struik Publishers, Cape TownGoogle Scholar
  29. Sutherst R (2003) Prediction of species geographical ranges. J Biogeogr 30:1–12. doi: 10.1046/j.1365-2699.2003.00861.x CrossRefGoogle Scholar
  30. Sutherst RW, Maywald GF (1985) A computerised system for matching climates in ecology. Agric Ecosyst Environ 13:281–299. doi: 10.1016/0167-8809(85)90016-7 CrossRefGoogle Scholar
  31. Sutherst RW, Maywald GF, Yonow T, Stevens PM (1999) Climex: predicting the effects of climate on plants and animals. Climex 1.1 User guide. CSIRO Publishing, VictoriaGoogle Scholar
  32. Swarbrick JT, Finlayson CM, Cauldwell AJ (1982) The biology and control of Hydrilla verticillata. Biotrop special publication no. 16, Bogor, Indonesia. 34 ppGoogle Scholar
  33. Weldon LW, Blackburn RD, Harrison DS (1969) Common aquatic weeds, 1973 edn. Dover Publications, New York 43 ppGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Julie A. Coetzee
    • 1
    • 2
  • Martin P. Hill
    • 1
  • Dieter Schlange
    • 1
  1. 1.Department of Zoology and EntomologyRhodes UniversityGrahamstownSouth Africa
  2. 2.Agricultural Research Council, Plant Protection Research InstituteQueenswoodSouth Africa

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