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.

Integrated Ecological Assessment of Heavily Polluted Sedimentary Basin within the Broader Industrialized Area of Thriassion Plain (Western Attica, Greece)

“…Similar prospect about the Lake's water quality were published by Mentzafou et al [56] in a relatively recent study comprising the evolution of important ecological features. The electric conductivity range between 8982 and 27,400 lS/cm depicts a dropping trend when comparing with values since 1984, thanks to the uplifting of the weir.…”

Severe Coastal Hypoxia Interchange with Ocean Acidification: An Experimental Perturbation Study on Carbon and Nutrient Biogeochemistry

“…In Elefsis Bay, temperature and salinity in the upper 15 m of the water column increase fast in summer due to atmospheric heating and evaporation [20], which can justify the higher A T values of this period. In general, Elefsis Bay A T values were found higher than other Mediterranean coastal areas [3,7,61,63] although all of them receive freshwater discharges of rivers and streams crossing watersheds composed mainly of carbonate rocks resulting in significant alkalinity inputs. Elefsis Bay receives surface runoff originating from the surrounding calcareous mountains [61] and its A T is higher even from the adjacent Saronikos Gulf [65].…”

“…In general, Elefsis Bay A T values were found higher than other Mediterranean coastal areas [3,7,61,63] although all of them receive freshwater discharges of rivers and streams crossing watersheds composed mainly of carbonate rocks resulting in significant alkalinity inputs. Elefsis Bay receives surface runoff originating from the surrounding calcareous mountains [61] and its A T is higher even from the adjacent Saronikos Gulf [65]. Additionally, it has been pointed out for areas with restricted mixing and/or characterized by significant inputs of DOM from land that organic bases contribute remarkably in A T [66,67].…”

“…In Elefsis Bay, the pycnocline is an intermittent feature (see Introduction), which after collapse could enrich shallower depths with CO 2 originating from bottom waters. Elefsis Bay is the waterfront of the Thriassion plain that has been a heavily industrialized, urban area for several decades [61]. In consequence, high CO 2 air produced by anthropogenic activities near the coast can be advected via atmospheric circulation over the surface of Elefsis Bay and therefore increase the flux of CO 2 into surface waters.…”

Climate Change and Man-made Interventions, as Destabilizing Factors of the Coastal Zone: Some Examples of Coasts and Coastal Wetlands in Urban, Peri-Urban Areas and Natural Parks in Greece

“…Coastal urban and industrial sprawl has had a profound impact on peri-Urban natural resources, particularly affecting the ecological integrity of wetlands and other transitional water bodies [18]. In recent decades, peri-urban areas of Mediterranean cities have witnessed rapid land use changes, industrial development, intensive agricultural practices and poor water management practices, often causing the elimination or irreversible impacts on fragile water bodies such as coastal lagoons and small lakes [19,20]. Thus, quantification of these factors becomes more difficult due to their variability and coupling of the processes that affect coastal areas, and also to the frequency at which coastal changes occur [21].…”