EVROTAS

River Basin

The Evrotas River drains a mid-altitude Mediterranean basin, located at the South-eastern Peloponnese. The catchment covers a total area of 2418 km2. Average annual temperature is 16ºC and mean annual precipitation 803 mm. The vast majority of the river basin is covered by natural and semi-natural areas accounting for 61% of the total river basin, followed by agricultural areas that cover 38% while urban areas account for 1%.

Potential stressors

The dominant pressures in Evrotas derive mainly from agricultural activities and include overexploitation of water resources for irrigation, disposal of agro-industrial wastes (mainly oil mills), agrochemical pollution and hydromorphological modifications. Overexploitation of groundwater aquifers and water abstraction from surface waters led to a dramatic long-term discharge reduction as well as artificial desiccation of large parts of the Evrotas main stem and tributaries, particularly during dry years. The estimation of the hydroperiod of remaining pools and the time of desiccation of river reaches is critical for management and conservation purposes. Only one waste water treatment plant exists in the basin (city of Sparta), while villages are served by traditional permeable and impermeable cesspools. From an ecological point of view, the Evrotas basin can be characterized as a unique biodiversity hotspot in Greece, including many local endemic plants and vertebrates. This high proportion of endemics is attributed to the complex geological and climatic history of the area which, combined with geographical isolation and environmental diversification, have provide conditions to speciation. As a result of drought, massive fish deaths occur in summer and three native range-restricted endemic fish species, and especially Squalius keadicus, are threatened.

Globaqua contributions

• to analyse water and sediment quality;
• to investigate the influence of multiple stressors on biodiversity and ecosystem functioning;
• to test the effect of water scarcity and pollution performing specific experiments in river segments affected by oil mills and water diversions;
• to assess change scenarios in the water resources ecosystem services and the effects in socio-economic development at both basin and river segment scales.

Contact person: Nikos Skoulikidis (HCMR), [email protected]