Macrozoobenthos monitoring in relation to dredged sediment disposal: The case of the Marano and Grado Lagoon (northern Adriatic Sea, Italy)

Abstract

Coastal lagoons often require direct human intervention, such as dredging and the disposal of dredged material, to maintain the safety and accessibility of navigation channels. Dredging may have short and long-term effects on macrozoobenthic communities. Because they respond relatively quickly to anthropic and natural stress, benthic invertebrates are considered a biological quality element sensu Water Framework Directive 2000/60/CE (WFD) used to assess the ecological status in transitional water such as coastal lagoons.The monitoring of dredged areas and the subsequent comparison to the ecological quality status (EcoQS) sensu WFD in the Marano and Grado Lagoon has revealed that macrozoobenthic communities are slightly unbalanced and tolerant species prevailed. In this naturally stressed environment, the recovery time after the disturbance caused by dredging was three to six months, and richness and diversity were mostly related to the salinity range and distance from sea inlets.