A comparison between different biological water quality indexes in the Llobregat Basin (NE Spain)

Summary

Three biological water quality indexes are compared in the Llobregat River Basin. Two indexes are based on macroinvertebrate community: BILL, an index for the Llobregat based on the Trent River index and BMWP', an approach to the original BMWP for the Iberian Peninsula. The third index is based on benthic diatom: the CEE index. The diatom community responds faster than the macroinvertebrate to changes in environmental conditions, and offers additional information with which to interpret the response of the river to pollution.