Biodiversity assessment and ecotypology of the Taanzoult plain running water (Aguelmam Sidi Ali, Morocco)

Abstract

The Taanzoult plain is an integral part of the Aguelmam Sidi Ali wetland in the central Moroccan Middle Atlas. Its composition, of several geomorphological facies and terrestrial and aquatic habitats, offers consequent ecosystemic and socioeconomic services. Nevertheless, it is subject to strong anthropic pressure. The objective of this study is to measure the biodiversity and to evaluate the anthropogenic interactions within the aquatic environment. Benthic population dynamics were analyzed at seven monthly stations along the 12-month hydrobiological cycle. The study allowed the inventory of 25,432 individuals divided into nine taxonomic classes. The taxonomic wealth is 106 taxa belonging to 92 genera and 64 families of which 70 taxa were recorded at water sources and 77 taxa at the streams. This richness is composed mainly of 64% of insects, 10% of clitellates, 9% of gastropods and 9% of crustaceans. The quantitative and qualitative biological indicators have generally concluded to a poor water quality for both springs and streams. Moreover, the bioindicator species of the good quality of water resources and the surrounding terrestrial ecosystem (Odonata and Plecoptera) are less present despite the absence of their aquatic predators (fish). Thus, the presence of Lymnaeidae and Planorbidae hosts of several pathogens responsible for waterborne diseases and the presence of Anopheles (Culicidae) agent responsible for malaria. In this context, the aquatic biodiversity is significantly influenced by the anthropozoogenic impact according to a spatiotemporal typology. Indeed, these observations highlight aquatic life degradation and put in suspicion the quality of drinking water and hydropathy. So, it would be judicious to set up a rigorous surveillance system to prevent the imminent health risk and to regulate the pastoral activity in the wetland, in order to foresee adequate development of the water sources in order to perpetuate the offered ecosystem services.