Integrated ecological assessment and restoration planning in a heavily modified peri-urban Mediterranean lagoon

Abstract

An integrated ecological assessment and restoration plan has been developed for Koumoundourou Lake, a heavily modified peri-urban lagoon near Athens, Greece. After the construction of an artificial weir on the coastal lagoon’s canal outlet with Elefsina Bay, the water quality has improved and a short-term decrease in heavy metal concentrations in sediments is noted, which indicates a slow amelioration during the last decade. Nevertheless, the weir construction since the mid-1990s has changed the hydrological conditions of the wetland; it inevitably blocked marine fish movement and extirpated several fish species, while the area occupied by submerged aquatic vegetation has expanded due to the reduction in the lagoon water’s salinity. In order to maintain the improved water quality and ecological potential of Koumoundourou Lake, the construction of a fish pass within the sluice is recommended that would allow the free passage of fishes (particularly gray mullet mugilidae). Although this is expected to affect the current hydraulic conditions of the lagoon and may increase the salinity and slightly decrease the time renewal of the water, the lagoon’s ecological potential is expected to improve as the food web will be enriched.