Ecological recovery in a river polluted to its sources: the River Tame in the English Midlands

In many industrialised regions particularly in Britain, rivers have been impounded for use by mills, polluted by multiple point sources and channelised to the very source over many centuries (e.g., Bracegirdle 1973; Lester 1975; Harkness 1982; Holland & Harding 1984; Haslam 1991). Since the 1960s, the ecological recovery of such historically polluted and disturbed rivers in Britain has been remarkable. Long reaches of once black, foetid, fishless watercourses, some almost completely devoid of macroscopic biota, have been transformed into clear streams and rivers with diverse floras and faunas and prolific fish populations. This transformation is perceived to have been the result of a number of factors, including law, public pressure, new technologies, new infrastructure and changes in the economy and industry. Even so, ecological recovery is still poorly advanced in some rivers and the reasons for this have not been explained in any detail. This short chapter uses sets of long-term chemical and biological data from three sites on a Midland river in a preliminary analysis of the possible reasons for the variable rates of ecological recovery and the relationship between the long-term chemical and biological changes in the river. It is part of a series of longer term studies of the problems associated with ecological recovery of polluted rivers (e.g., Langford et al. 2009)