, Volume 415, Issue 0, pp 243–248 | Cite as

Succession of Egeria densa in a drinking water reservoir in Morbihan (France)

  • A. Dutartre
  • J. Haury
  • A. Jigorel


Located in western France, the Pen Mur dam of Muzillac (Morbihan) is mainly used for the production of drinking water and for fishing. Over the past few years, the upstream part of this eutrophic waterbody has been invaded by Egeria densa. To define suitable methods for the management of this plant, a 1996 study focused on the morphometric characteristics of the reservoir, the quality of its water and sediments, the diversity of its vegetation and various aspects of colonisation by E. densa. Analyses of usage and pollution were also made, as well as a review of the techniques available to control the development of this species. Based on the results of this study, a management plan was put forward. Studies in 1997 and 1998 showed a significant decline in the level of colonisation. This was probably due to the substantial floods which uprooted submerged plants in winter, followed by massive ice formation during winter and warm temperatures in spring leading to a development of cyanobacteria which are detrimental to macrophytes. Monitoring the competition between E. densa and the cyanobacteria could lead to determination of the causes of the predominance of one or the other.

Egeria densa succession water quality management reservoir France 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Cook, C. D. K. & K. Urmi-König, 1984. A revision of the genus Egeria (Hydrocharitaceae). Aquat. Bot. 19: 73–96.Google Scholar
  2. Dutartre, A., J. Haury, A. Jigorel & C. Laplace, 1997. Possibilités de gestion de l'invasion de la retenue de Pen Mur (Muzillac, Morbihan) par une plante aquatique exotique: Egeria densa. Cemagref, ENSA/INRA, Bordeaux Rapport pour le Conseil Général du Morbihan: 142 pp.Google Scholar
  3. Dutartre, A., J. Haury & A. M. Planty-Tabbachi, 1997. Macrophytes aquatiques et riverains introduits en France. Bull. Fr. Pêche Piscic. 344–345 (1–2): 407–426.Google Scholar
  4. Feuillade, J., 1961. Une plante aquatique nouvelle pour la France Elodea densa (Planch.) Casp. Bull. Soc. Linnéenne Normandie 10 (2): 47–51.Google Scholar
  5. Getsinger, K. D. & C. R. Dillon, 1984. Quiescence, growth and senescence of Egeria densa in lake Marion. Aquat. Bot. 20: 329–338.Google Scholar
  6. Haramoto, T. & I. Ikusima, 1988. Life cycle of Egeria densa Planch., an aquatic plant naturalized in Japan. Aquat. Bot. 30: 389–403.Google Scholar
  7. Howard-Williams, C., 1993. Processus of aquatic weed invasions: the New Zealand example. J. Aquat. Plant Mgmt 31: 17–23.Google Scholar
  8. Jigorel, A. & G. Bertru, 1993. Endogenic development of sediments in a eutrophic lake. Hydrobiologia 268: 45–55.Google Scholar
  9. Reddy, K. R., J. C. Tucker & W. F. Debusk, 1987. The role of Egeria densa in removing nitrogen and phosphorus from nutrient enriched waters. J. Aquat. Plant Mgmt. 25: 14–19.Google Scholar
  10. Tanner, C. C., J. S. Clayton & R. D. S. Wells, 1993. Effects of suspended solids on the establishment on growth of Egeria densa. Aquat. Bot. 45: 299–310.Google Scholar

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • A. Dutartre
    • 1
  • J. Haury
    • 2
  • A. Jigorel
    • 3
  1. 1.Cemagref, Unité Qualité des EauxCestas CedexFrance
  2. 2.ENSA-INRA, 65Rennes CedexFrance
  3. 3.INSA, 20Rennes CedexFrance

Personalised recommendations