The decline in ecological quality and conservation value of European fresh waters is an all too
common phenomenon. In lowland Britain the main anthropogenic impact on aquatic systems is that
associated with elevated nutrient loading. The Broads are internationally important wetlands
spanning a number of river basins in East Anglia. The Broads have suffered, along with other
wetlands, and it is chiefly eutrophication that has had a deleterious effect on the system (Mason &
Bryant 1975, Moss 1977) with a resultant decline in their ecological quality and conservation value.
One of the changes in the ecological structure and functioning of shallow lakes in response to
enrichment is an alteration in their macrophyte flora (Ris & Sand-Jensen 2001) and in extreme
cases there may be the complete loss of submerged plants (Scheffer et al. 1993). The loss of the
diversity of the macrophyte flora in the Broads is perhaps the main factor in the decline in their
conservation value
