Invertebrate colonisation and community succession of a man-made river channel.

R.E. Baker, A.L. Robertson, and P.J.A. Shaw. School of Life Sciences, University of Surrey Roehampton, West Hill, London SW15 3SN, U.K.

The Jubilee River is a man-made flood alleviation channel in the River Thames catchment U.K. which has been constructed over the last five years. This new 11.8 km channel is connected at either end to the River Thames and has been designed to resemble the natural river channel, whilst possessing several flood control structures. Five sites were monitored over 18 months, during which period the “river” has been transformed from a series of independent lentic pools to a continuous flowing lotic environment. The five sites included two reference sites in the River Thames and three sites, of differing ages, in the new river. Invertebrate samples were regularly collected from the hyporheos and instream and littoral epibenthos and meiofaunal organisms were isolated and identified. Physico-chemical data was collected upon each site visit. The invertebrate community was found to change significantly, both in diversity and abundance over the survey period in the new river whilst remaining relatively constant in the River Thames. These changes were more marked in the epibenthic habitats than in the hyporheic environment. However, distinct differences were evident between the sites of different ages within the new river.