In the Caleri lagoon, a coastal lagoon in the Po River Delta, Northern Adriatic, the transplant of the dwarf eelgrass Zostera noltei was used as a nature-based solution to attempt the ecological restoration of a previously depleted lagoon area. A total of 135 15-cm-diameter sods were transplanted, with the donor site at the Venice lagoon. Using unmanned aerial vehicles (UAVs), eelgrass transplants were mapped and monitored with great precision. After two years, the area covered by eelgrass increased from the initial 2.5 m² to 60 m². Changes in the community structure and on the frequency of biological traits of macrobenthos occurred at the transplant site, with a higher frequency of epifaunal predators and herbivores, and of organisms with longer life spans and larger body sizes. Sensitive and indifferent taxa were always higher in the transplant site than in the bare bottom control site, where opportunistic taxa continued to dominate. Ecological quality status measured through M-AMBI and HBFI indices showed a clear improvement in the transplant site. The rapid changes in benthos demonstrate that even relatively small-scale transplantation of dwarf eelgrass can restore faunal communities very rapidly.

In the Caleri lagoon, a coastal lagoon in the Po River Delta, Northern Adriatic, the transplant of the dwarf eelgrass Zostera noltei was used as a nature-based solution to attempt the ecological restoration of a previously depleted lagoon area. A total of 135 15 cm diameter sods were transplanted, with the donor site at the Venice lagoon. Using unmanned aerial vehicles (UAVs), eelgrass transplants have been mapped and monitored with great precision. After 2 years, the area covered by eelgrass increased from the initial 2.5 m2 to 60 m2. Changes in the community structure and on the frequency of biological traits of macrobenthos occurred at the transplant site, with a higher frequency of epifaunal predators and herbivores, of organisms with longer life spans and larger body sizes. Sensitive and indifferent taxa were always higher in the transplant site than in the bare bottom control site, where opportunistic taxa continued to dominate. Ecological quality status measured through M-AMBI and HBFI indices showed a clear improvement in the transplant site. The rapid changes in benthos demonstrate that even relatively small-scale transplantation of dwarf eelgrass can restore faunal communities very rapidly.

Within the framework of proximal sensing, monitoring early-stage seagrass colonization in turbid waters presents challenges due to the spectral similarity between the dwarf eelgrass Zostera noltei and ephemeral macroalgae. A preliminary study previously demonstrated the utility of high-resolution Unmanned Aerial Vehicle (UAV) imagery for general monitoring through visual inspection (Mistri et al., 2025). However, the reliance on manual detection and known transplantation coordinates limits the scalability of the approach. In this study, we take a further step to overcome these limitations by applying pixel-based supervised classification to high-resolution orthomosaics. This allows for precise and quantitative tracking of the spatial evolution of seagrass meadows over time.Ultra-high-resolution aerial surveys were conducted in the Caleri Lagoon (Po River Delta, Italy) using a DJI Air 2S UAV flown at an altitude of 7 meters, achieving a theoretical ground sampling distance of 0.2 cm/pixel. The collected imagery was processed into georeferenced orthomosaics and analyzed using a supervised Maximum Likelihood Classification algorithm based on Bayes’ theorem. To isolate the spectral signal of the target seagrass, the probabilistic framework incorporated 40 regions of interest for each of five classes: seagrass, green algae, red algae, shadow, and background. To reduce high-frequency 'salt-and-pepper' noise, a post-classification Sieve filter (20×20 pixel window) was applied, refining patch segmentation based on neighborhood mode.Multitemporal analysis revealed a distinct non-linear expansion trajectory within the 0.5-hectare study area. Starting from a planted footprint of just 2.5 m² (~0.05% of the study area) in August 2023, the seagrass colonies expanded to 60 m² (1.2%) by June 2024, reaching approximately 716 m² (14%) by October 2025.These results demonstrate that combining low-altitude UAV photogrammetry with probabilistic classification offers a highly repeatable and scalable framework for quantifying restoration dynamics. This methodology effectively overcomes the limitations of manual monitoring, enabling the detection of the subtle, non-linear growth patterns typical of early-stage colonization.

Beach sands may harbor human pathogens and antibiotic resistance genes, prompting the proposal of low-dose quicklime (CaO; 1–3% w/w) as a remediation strategy to improve microbiological quality in highly contaminated areas. After application, CaO is converted into calcium carbonate (CaCO₃), yet the ecological effects of this residual compound on benthic fauna remain poorly understood. This study evaluated the short-term impact of CaCO₃-enriched sediment (3% w/w) on the Manila clam, Ruditapes philippinarum, under controlled mesocosm conditions. Adult clams were exposed for one week, and survival, burrowing behavior, feeding- and metabolism-related parameters (clearance, ingestion, absorption efficiency and rate, ammonia excretion), and oxidative stress (malondialdehyde, MDA) were assessed using a hierarchical design, with a tank as the experimental unit. No significant differences were detected between control and CaCO₃-enriched treatments for any measured endpoint. Survival remained high, functional responses showed overlapping ranges, and MDA levels did not differ significantly between groups. Although limited to short-term exposure and a single concentration, these findings suggest that residual CaCO₃ derived from quicklime application did not induce detectable adverse effects in adult R. philippinarum under the tested conditions. Further long-term and multi-species studies are needed to confirm ecological safety.