ASSESSING THE ECOLOGICAL EFFECTS OF GROUNDWATER ABSTRACTION ON CHALK STREAMS - 3 EXAMPLES FROM EASTERN ENGLAND

The invertebrate communities and environmental characteristics of thre e English chalk streams; the rivers Wissey, Rhee and Pang, were invest igated to determine the effects of groundwater abstraction. The data w ere collected as part of a larger study of 21 UK rivers subject to a v ariety of types of abstraction. A variety of analytical techniques, in cluding a novel multivariate analysis (co-structure analysis), and the use of species profiles, showed significant physical and biotic diffe rences between the three rivers and between impacted and natural sites on each river. The observed faunal differences are discussed in relat ion to existing data on the impact of natural droughts on chalk stream s, and the problems associated with determining the effects of non-poi nt source abstractions (such as from groundwater) are considered.