Experimental design and field deployment of an artificial bio-reef produced by mollusk shell recycling.

Shellfish farming is considered a highly sustainable form of aquaculture that has developed rapidly worldwide. Unfortunately, today biological and chemical pollution of the oceans and marine waters is widespread and has multiple negative impacts on marine ecosystems, which are exacerbated by global climate changes. In addition, such impacts on fisheries and aquaculture are significant in inducing socio-economic losses. Therefore, it is necessary to develop innovative solutions to improve productivity and environmental performance in line with the blue sustainable economy (European Green Deal). However, one upcoming problem associated with shellfish consumption is shell waste and its disposal. In addition, the percentage of wasted shells destined for reuse is much lower than the one accumulated in landfills or in more or less well-managed sites. This represents a weakness of the shellfish farming sector that can only be mitigated through a project of shellfish waste recycling moving towards the circular economy, with undoubted environmental and economic advantages. In the present study, we present a possible solution for recycling clam shells coming from the waste of the fishing industry (circular economy). Indeed, three eco-friendly bio-reefs for the stabilization and implementation of marine biodiversity (blue economy) were realized using additive manufacturing technology (3D printing) for large dimensions (technological innovation). Furthermore, before deploying the reefs on the sea bottom, they were colonized with oysters to promote repopulation.

Linking flow-stream variability to grain size distribution of suspended sediment from a satellite-based analysis of the Tiber River plume (Tyrrhenian Sea).

Several coastal regions on Earth have been increasingly affected by intense, often catastrophic, flash floods that deliver significant amounts of sediment along shorelines. One of the critical questions related to the impact of these impulsive runoffs is "are flash floods more efficient in delivering non-cohesive sandy sediment along the coasts?" Here we relate flow stages (i.e., from erratic to persistent) to the grain size distribution of the suspended load, by performing a synergic analysis of in-situ river discharge and satellite-retrieved grain size distribution, from 2002 to 2014, covering the 2012 Tiber River (Italy) exceptional flood event. Our analysis shows novel and promising results regarding the capability of remote sensing in characterizing suspended sediment in terms of grain size distribution and reveals that erratic stages favour delivering of non-cohesive sandy sediment more than the persistent stages. This conclusion is supported by numerical simulations and is consistent with previous studies on suspended sediment rating curves.

Quantifying the impacts of the human activities on the evolution of Po delta territory during the last 120 years.

Our study investigates the land use evolution of the Po River Delta (Italy, about 18,000 ha) over the last 120 years to evaluate the impacts of human activities. The various land uses and their evolution have been evaluated through the analysis of different historical maps and aerial photographs. The land use maps have been realized using the third level of the Corine-Land-Cover (CLC) legend. The assessment of the anthropic pressures on the evolution of the territory has been done by expert's judgment on the impact of the different land uses on natural environment. From 1894 to 2015, the land use change is mainly characterized by a conversion of the natural wetlands into agricultural areas, and fishing valleys classified as artificial wetlands in the period between 1892 and 1978. As a result of agricultural and economic policies, agricultural practices became a major driver of wetland loss, and then the urbanization related to agricultural settlement had provided additional impacts on wetland loss. Scientists and technicians indicate that industrial/commercial and harbour related activities are the most important factors that contribute to the degradation of the land use, while, positive impacts have been attributed to natural land use and in particular lagoons, forests and green areas. The cumulative human impact maps show that more than 50% of the territory is degraded during the following three periods: i) a first period (1894-1955) of good environmental conditions mainly due to the presence of highly positive ecological systems; ii) a second period (1955-2000) of intense degradation along coastal areas and the transportation roads; iii) reduction of degradation processes. Finally, we believe our methodology represents an effective geospatial approach in land management: the map of human pressures and the involvement of the experts highlight to managers and policy-makers the impacts of human activities.