Programma della conferenza

RENOVATE is an Italian applied research project whose main objective is to restore the functions and services of the marine ecosystem affected by the expansion of the Civitavecchia Port Hub. It includes restoration and mitigation measures for the priority Habitat 1120* (Posidonia oceanica) and some biocoenoses of Habitat 1170 (Reefs, such as Coralligenous, Cystoseira s.l.) and two species of high naturalistic and ecological importance: Corallium rubrum and Pinna nobilis.

RENOVATE is an ambitious Nature-Based Solutions (NBS) project based on innovative, holistic approaches aimed at achieving medium- to long-term goals to restore the functionality of habitats to the extent that they have been lost. The design phase, the experimental set-up and the duration of the project (10 years) ensure the success of the actions through rigorous planning, continuous monitoring, maintenance, review and adaptation of the experimental actions based on the results obtained.

To develop this approach, it is necessary to implement an integrated modelling and observing system and operational modelling at regional and coastal scales. This will contribute to the planning phase of restoration, development of an early warning system for extreme events, dredging and avoidance of potential impacts, implementation of ecological compensation measures to restore ecosystem services, siting and implementation of NBS and monitoring of recovery of ecosystem services over 10 years.

Preliminary results will be presented showing promising trends in the recovery of Cystoseira s.l. and Coralligenous. Initial monitoring data indicate positive responses that emphasize the potential effectiveness of the implemented measures.

Aquaculture is one of the most rapidly expanding sectors in global food production, contributing slightly over half of the world's fish for human consumption. However, concerns regarding the environmental impact of aquaculture operations and the potential for sustainability persist. Coastal areas designated for aquaculture often experience compromised water quality due to human activities, such as wastewater drainage and discharge of aquaculture residues, resulting in ecosystem damage. In light of these concerns, integrating effective remediation systems with aquaculture becomes imperative.

Previous studies have highlighted the role of mussels in reducing chlorophyll, phosphorus, and nitrogen levels in salmon farming. Recent research demonstrated their efficacy as biofilters for microplastics and metals. This study aims to further explore the potential of mussels as biofilters in fish farming systems.

Mussels were exposed in microcosms at a density of 1 individual per liter, either in the presence or absence of algae. Mussels demonstrated significant metal accumulation abilities over a 10-day exposure period. Statistical analysis using robust linear regression models indicated that external metal concentration significantly influenced internal metal concentration. Metals such as Ag, Cd, Co, Cr, and Pb showed high significance across all exposure levels, both in the presence and absence of algae. Other metals, including Cu, Fe, Ni, V, and Zn, showed partial significance, while Mn did not exhibit a significant effect.

We developed a mathematical model for heavy metal removal in aquaculture. This model incorporates the decay rate k for each metal species and includes parameters such as metal input, system volume, and the number of mussels to be deployed in the aquaculture farm. The numerical model effectively predicts the reduction of metal concentrations over-time, providing critical insights for designing mussel-based biofilters. These findings contribute to the broader goals of the Italian project Fish RISE (ARS01_01053), supporting sustainability and environmental protection in aquaculture practices

Seagrass meadows and macroalgal (Fucales) forests are hot spots of biodiversity in coastal areas and play a key role in the provisioning of ecosystem services. These habitats experienced regression in the Mediterranean basin in the last decades, due to a combination of multiple anthropogenic and climate-induced impacts. The ecological restoration of these habitat-forming species is a priority to reverse biodiversity loss and for the recovery of their ecosystem functions. We report here successful case studies of ecological restoration of seagrass (Cymodocea nodosa) and Fucales (Gongolaria barbata) along the coasts of the Marche region (NW Adriatic Sea). Benthic biodiversity (using meiofauna as a proxy) was analyzed in terms of abundance, richness of taxa and taxonomic/species (nematode) composition. Three interventions were carried out: 1) transplanting of the seagrass Cymodocea nodosa at Gabicce and the restoration of the brown alga Gongolaria barbata in the Conero Riviera and in Site of National Interest (SNI) of Falconara Marittima. At “Falconara” site we combined active and passive restoration interventions, as this site has been interdicted for years. All the applied approaches were successful in restoring the damaged habitats and recovering natural populations. Active and active/passive restoration interventions, however, 6/12 months after the interventions, showed both biodiversity and assemblage structure different from the controls when considering meiofaunal assemblages as proxy of biodiversity. Nematodes resulted useful indicators of restoration success. Macrophytes’ restoration can be successful and has positive effects on benthic local biodiversity, however, is a relatively long process that can take years to reach a complete recovery. A multilevel approach and habitat inter-connected approach could be useful to increase restoration success and resilience of damaged vegetated habitats.

An increasingly common approach to halting degradation and promoting the recovery of marine ecosystems and the provision of associated ecosystem services is the implementation of seagrass restoration projects. However, evaluation of the success of seagrass restoration is still based on long-term monitoring of structural indicators such as survival and density of transplanted plants. In contrast, functional indicators may be better suited to provide more rapid information on the recovery of ecosystem functions, which is usually considered to be the main objective of ecosystem restoration. In this study, the Five-star System and the Recovery Wheel monitoring framework, launched by the Society for Ecological Restoration in 2016, were applied to assess the overall progress one year after a restoration intervention in a degraded area (Gulf of Palermo, Sicily, Mediterranean) by transplanting Posidonia oceanica. Six ecosystem attributes covering functional and structural aspects: (i) physical conditions (sediment dynamics), (ii) species composition (fish composition and functional response), (iii) ecosystem function (habitat processes and interactions), (iv) absence of threats (chemical pollution), (v) structural diversity (fish biodiversity) and (vi) plant health (growth and physiology of P. oceanica) were selected and monitored at the restored site and at a reference site (i.e. the healthy nearby donor meadow). Functional attributes showed an overall improvement over the reference site one year after transplantation, while indicators of chemical pollution and fish diversity did not change over time, and P. oceanica health indicators actually deteriorated. Although a period of less than 10 years is usually considered too short to assess the success of ecosystem restoration interventions, here we have shown that the first signs of functional recovery are already detectable one year after seagrass transplantation. However, the structural response of associated fish, the reduction in pollution levels and, even more importantly, the improvement in plant health take longer to recover.

A crucial challenge in ecosystem restoration, due to the ecological system complexities and the spatial and temporal scales involved, is the prediction of system evolution, the associated uncertainties and the final outcomes. A natural approach to this goal is the use of process-based models, but their requirements in terms of data and mechanistic understanding of system ecology still limit their adoption in the restoration of high complexity systems. Indeed, despite the large amount of data globally acquired, the lack of shared comprehensive strategies for what needs to be collected and how, promotes the adoption of heuristic approaches based on collections of failures and successes. A remarkable example in this context is provided by the restoration of Posidonia oceanica meadows, one of the most important Mediterranean marine coastal ecosystems in terms of productivity, biodiversity and control of local, regional and even global ecological dynamics. The limited resilience of these ecosystems, threatened by diverse anthropogenic pressures, forces the adoption of restoration approaches with variable and hardly predictable degree of effectiveness. With the aim to transitioning from heuristic to mechanistic restoration approaches, the research focused on creating an individual-based model of meadow evolution grounded in Dynamic Energy Budget theory, and a cured and harmonized information base on P. oceanica ecology, summarizing more than 6 decades of research in the form of an open geo-database. Results revealed striking imbalances in data type, quality and redundance, with surprising shortage of usable data for model development and parameterization. The coupling between the information base and the model, however, has the potential to form a feedback loop providing the much-needed strategy to move from heuristics to mechanistic approaches. Indeed, the model’s functional hypotheses can orient the collection of data embedded in clear theoretical processes, which in turn allow model development ensuring the effectiveness of restoration approaches.

Active restoration actions are considered reliable strategies for enhancing seagrass ecosystems within an acceptable time frame. Effective future seagrass restoration management requires valuable information on the effectiveness of past restoration actions. At this aim, we have quantitatively collated evidence of restoration actions for the slow-growing seagrass Posidonia oceanica, endemic to the Mediterranean Sea. A meta-analysis of the literature, consisting of 33 documents and 1223 case studies was conducted to provide evidence on any human mediated active restoration, transplanting or rehabilitation outcomes of P. oceanica. Results identified the geographical distribution of interventions across countries, their environmental conditions (such as the transplanting depth and type of substrate) as well as the procedural contexts of trials including surface, transplanted plant portion, anchoring technique and monitoring variables. The current study identified an overall lack of standardization in the practices and methodologies used, as well the monitoring variables that severely constrain the analysis of P. oceanica restoration outcomes. However, positive outcomes were observed when transplanting in matte substrate, using plagiotropic rhizomes and modular anchoring systems. Moreover, seagrass restoration success is related to shallow transplants, using deeper donor shoots, transplanting with low density and, not surprisingly, when monitoring more than 30 months. Overall, our outcomes clamours for increased funding for monitoring and reporting outcomes, and improved monitoring consistency, that could greatly enhance the understanding of P. oceanica restoration keeping it more effective.