Effects of restoration approaches on benthic assemblages in the saltmarshes of a Mediterranean lagoon

Abstract

Saltmarsh restoration is widely implemented in the Venice lagoon, yet the extent to which different restoration designs influence benthic and epibenthic communities remains unclear. This study compares natural and artificial saltmarshes across two lagoon basins (central and northern), accounting for large-scale environmental gradients and local habitat characteristics. Benthic and epibenthic communities were analyzed in creeks. Basin-scale conditions, particularly salinity and sediment characteristics, emerged as the main drivers of community structure, with clear differences between lagoon sectors. The central basin supported more diverse and functionally heterogeneous assemblages, whereas northern sites showed lower diversity and were dominated by deposit feeders. The effects of restoration design were context-dependent. In the northern basin, artificial and natural saltmarshes hosted similar communities, while in the central basin, artificial marshes built with sandy sediments supported distinct assemblages compared to natural sites. Overall, while environmental gradients constrain community patterns, restoration design - especially sediment characteristics - can influence ecological trajectories, highlighting the need for site-specific restoration strategies.