Macroinvertebrates assemblages in the Canary Islands and Madeira

Abstract

This study describes the freshwater macroinvertebrates assemblages in 17 streams of four of the Canary Islands (Tenerife, Gran Canaria, La Palma and La Gomera) and 10 streams of Madeira Island, at least in two seasons of the year. Without the Diptera, since this group has not been identified, a total of 71 taxa have been found in the Canary Islands belonging to 34 families. In Madeira, a total of 63 taxa belonging to 33 families have been found. The biogeographical origin of the species is mostly Paleartic region and endemic. Endemisms have a significant presence in both archipelagos, being around one third in both cases. The endemicity in Tricoptera and Coleoptera is remarkable. There seems to be a tendency towards greater biodiversity and endemicity in those currents in better conserved areas, that are found within the Natural Parks in the Canary Islands and in the high areas of Madeira. The status of freshwater macroinvertebrates is quite uncertain as recent data on these communities are scarce. The overexploitation of aquifers and the diversion of natural water flows for irrigation have caused the drying up of many of the natural flows, which inevitably endangers the fauna that inhabits them. The protection of a stream with a high conservation value is proposed to contribute to the conservation of the Macaronesian native freshwater macroinvertebrate fauna.