From Experiment to Example: Evaluating the Sustainability of Shore Nourishment in the Southeastern Baltic (Palanga, Lithuania)

Coastal erosion and increasingly severe storms present a growing challenge to the sustainable management of sandy shorelines. This study examines the geomorphological, sedimentological and geochemical responses of the Palanga coastal area in the Lithuanian Baltic Sea to beach nourishment projects implemented between 2006 and 2012. A multi-parameter approach was used, combining cross-shore profile monitoring with grain-size, magnetic susceptibility, mineralogical and geochemical analyses, in order to assess sediment redistribution and post-nourishment adjustments. The results demonstrate that nourishment projects substantially increased beach width, height and sand volume; however, the shoreline response was uneven in space and time. Subsequent years were characterised by gradual sediment redistribution along and across the coast, resulting in partial morphological stabilisation. Elevated concentrations of heavy minerals and trace elements immediately after nourishment indicated short-term enrichment from mineralogically distinct material, which was later diluted by natural reworking. The findings demonstrate that properly designed and monitored nourishment enhances coastal resilience, representing a human-induced adjustment within the prevailing coastal morphodynamic regime. While the socio-ecological effects were not directly evaluated, the identified geoindicators offer insights into the physical sustainability of coastal systems, emphasising the importance of evidence-based, adaptive management in line with the United Nations Sustainable Development Goals (SDGs 11, 13 and 14).