Habitat mapping for assessing coastal restored oyster reef effects

Understanding surrounding habitat conditions before oyster reef restoration is crucial to assessing its future impacts and achieved goals. The EU-co-funded LIFE NatuReef project may provide a peculiar case study of oyster reef restoration for biodiversity enhancement and coastal protection in the Mediterranean Sea. The intervention area is located near the Bevano River mouth, Municipality of Ravenna, within a NATURA 2000 site. The area represents a natural oasis characterised by transitional ecotones between fresh, brackish, and marine waters, as well as between woodland, dune, and sandy systems. Its terrestrial and aquatic habitats play an important ecological role as spawning and nursery areas. However, the beach is undergoing severe erosion, due to both natural and human reasons, and coastal habitats are under serious threat. Detailed habitat mapping has been conducted in the study area, combining terrestrial and marine remote sensing (e.g., LiDAR, photogrammetry, single- and multibeam sonar), direct sampling (e.g., sediments, benthos, vegetation), and on-site measures and observations (e.g., data loggers, oceanographic buoys, bird watching). Where appropriate, for example for the surrounding benthic communities, spatially referenced data were interpolated to obtain species distribution maps, while spatial correlation analyses between the different biotic and abiotic variables allow the identification of present anomalies and possible future effects of the restored reef. These baseline data and habitat mapping provide a critical baseline for detecting ecological changes following oyster reef restoration and support adaptive management by identifying ecologically sensitive areas and targeting restoration efforts to minimise negative impacts.