The use of Members of the Family Chydoridae (Anomopoda, Branchiopoda) as an Indicator of Lake Ecological Quality in Ireland

Abstract

ABSTRACTWe sampled chydorids (Branchiopoda, Anomopoda) from 29 Irish lakes between June 1996 andJuly 1997 in order to assess the usefulness of this group as an indicator of lake ecological quality,as required by the recently published EU Water Framework Directive. The lakes represented awide range of the physicochemical conditions found in Irish lakes. We identified 31 species ofChydoridae from the lakes and used multivariate analysis to elucidate the relationship between thechydorids and their environment. Groups of lakes were found to have distinct chydorid communi-ties, the structure and composition of which depended on environmental variables such as totalphosphorus, total nitrogen, alkalinity, conductivity and lake size. The study highlights the potentialvalue of this group as a biotic indicator of ecological change in Irish lakes.INTRODUCTIONIrish lakes are generally considered to be ofgood quality compared with those in other Eu-ropean countries, and more than 81% of 120 Irishlakes surveyed recently were classed as oligotrophicor mesotrophic (Lucey