Aquatic Ecology

, Volume 32, Issue 3, pp 211–216 | Cite as

Seasonality in macroinvertebrate community composition across a neglected ecological boundary, the freshwater-estuarine transition zone

  • S.D. Rundle
  • M.J. Attrill
  • A. Arshad


The boundary between freshwater and estuarine ecosystems at the extreme head of estuaries has received little attention from benthic ecologists. This short communication addresses this research caveat, presenting preliminary data on the spatial and temporal (seasonal) variation in the composition of benthic macroinvertebrate communities across the transition zone at the head of a small British estuary. Cluster analysis and multidimensional scaling ordination demonstrated that a distinct community occurred at a point just preceding the recognised transition between fresh and brackish waters (salinity <0.2PSU). This transition community contained a mixture of freshwater and estuarine taxa and, despite seasonal migrations at the head of the estuary, community structure remained significantly distinct from that at adjacent sites throughout the year. These preliminary data suggest that the community dynamics across the transition zone show complex patterns and may offer an important research opportunity in aquatic ecology.

macrofauna salinity gradient community analysis estuary 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Ahel M, Barlow RG and Mantoura RFC (1996) Effect of salinity gradients on the distribution of phytoplankton pigments in a stratified estuary. Mar Ecol Progr Ser 143: 289-295Google Scholar
  2. Attrill MJ, Rundle SD and Thomas RM (1996) The influence of drought-induced low freshwater flow on an upper-estuarine macroinvertebrate community. Wat Res 30: 261-268Google Scholar
  3. Chapman PM and Brinkhurst RO (1981) Seasonal changes in interstitial salinities and seasonal movements of subtidal benthic invertebrates in the Fraser River estuary, B. C. Est Coast Shelf Sci 12: 49-66Google Scholar
  4. Clarke KR (1993) Non-parametric multivariate analyses of changes in community structure. Austral J Ecol: 18: 117-143Google Scholar
  5. Clarke KR and Green RH (1988) Statistical design and analysis for a ‘biological effects’ study. Mar Ecol Progr Ser 46: 213-226Google Scholar
  6. Kenkel NC and Orloci L (1986) Applying metric and nonmetric multidimensional scaling to some ecological studies: some new results. Ecology 67: 919-928Google Scholar
  7. Kinne O (ed.) (1971) Marine Ecology: Volume 1, Environmental Factors. Wiley Interscience, LondonGoogle Scholar
  8. Minchin PR (1987) An evaluation of the relative robustness of techniques of ordination. Vegetatio 69: 89-107Google Scholar
  9. Montagna PA and Kalke RD (1992) The effect of freshwater inflow on meiofaunal and macrofaunal populations in the Guadalupe and Nueces estuaries, Texas Estuaries 15: 307-326Google Scholar
  10. Morris AW, Mantoura RFC, Bale AJ and Howland RJM (1978) Very low salinity regions of estuaries: important sites for chemical and biological interactions. Nature 274: 678-680Google Scholar
  11. Naiman RJ and Décamp H (1990) The ecology and management of aquatic-terrestrial ecotones. Man and Biosphere Series. UNESCO, ParisGoogle Scholar
  12. Remane A and Schlieper C (1971) Biology of Brackish Water. Die Binnengewässer Vol. XXV. E. Schweizerbartsche Verlagsbuchhandlung, StuttgartGoogle Scholar
  13. Schiemer F and Zalewski M (1992) The importance of riparian ecotones for diversity and productivity of riverine fish communities. Neth J Zool 42: 323-335Google Scholar
  14. Statzner B and Higler LWG (1986) Stream hydraulics as a major determinant of benthic invertebrate zonation patterns. Freshwater Biology 16: 127-139Google Scholar
  15. van der Maarel E (1990) Ecotones and ecoclines are different. J Veg Sci 1: 135-138Google Scholar
  16. Warwick RM, Carr MR, Clarke KR, Gee JM and Green RH (1988) A mesocosm experiment on the effects of hydrocarbon and copper pollution on a sublittoral soft-sediment meiobenthic community. Mar Ecol Progr Ser 46: 181-191Google Scholar
  17. Wolff WJ (1973) The estuary as a habitat: an analysis of data on the soft-bottom macrofauna of the estuarine area of the rivers Rhine, Meuse and Scheldt. Zoöl Verhand 126: 1-242Google Scholar

Copyright information

© Kluwer Academic Publishers 1998

Authors and Affiliations

  • S.D. Rundle
    • 1
  • M.J. Attrill
    • 1
  • A. Arshad
    • 1
  1. 1.Plymouth Environmental Research Centre, Department of Biological SciencesUniversity of PlymouthPlymouthUK

Personalised recommendations