Search Results (5)

The Pacific oyster Crassostrea gigas is one of the world’s most cultivated and prized molluscs. Although it is usually considered a luxury product, it meets all the requirements to be included in a sustainable diet, and its production and consumption have great potential for growth in the coming years. Oyster farming is a worldwide activity, with China and France as the main producers, but recently, the possibility of implementing the Italian production, mainly focused on clams and mussels, has been considered an interesting issue, especially due to the growing local and global demand. The present study has been carried out by collecting data from the Sacca di Goro, north-east Italy, the most important national mollusc farming area. Life cycle assessment (LCA) methodology was applied to two different farming scenarios in order to improve the overall sustainability of the process. Using OpenLCA™ software (GreenDelta, Berlin, Germany) and the ReCiPe^® midpoint (H) v.1.12 method, the environmental impacts of the traditional Italian farming technique, carried out entirely offshore in longlines, and the alternative option, in which the oyster seed pre-fattening phase was carried out in the lagoon, were calculated and compared. The results show that replacing the current pre-fattening phase with pre-fattening in a lagoon reduces CO₂ emissions by approximately 12% and all other impact categories by approximately 9%. In addition, non-recyclable plastic materials and fuel consumption emerged as the main environmental hotspots. Full article

Oyster shells are substratum for different epibiontic and endobiontic organisms, including pests and parasites. Rocellaria dubia is endolithic and facultative tube-dwelling bivalve, boring in different calcareous substrates, including the shells of bivalves. In 2020, R. dubia was found as endolithic in the shells of the Pacific oyster Magalana gigas, from an oyster farm off the Sacca di Goro lagoon (Emilia-Romagna region, Northern Adriatic Sea, Italy). The purpose of this study was to describe this newly recorded association. Altogether, 136 specimens of R. dubia were found in 15 oysters, photographed under a stereoscope, and their length was measured. Heavily infested oysters hosted tens of R. dubia borers, which were perforating the whole thickness of the oyster valves. The flesh of these oysters was heavily damaged, suggesting parasitic association. R. dubia specimens were categorized into three age classes (0–1, 1–2, and 2–3 years old). M. gigas/R. dubia might be a widespread association, overlooked due to the very scarce research on macrofauna associated with M. gigas. Considering the negative effects of R. dubia endobiosis on oyster fitness, and possible impacts on oyster aquaculture, further research should be conducted in order to elucidate the distribution and ecological characteristics of this parasitic association. Full article

Manila clam (Ruditapes philippinarum, Adams and Reeve, 1850) farming is a quantitatively important and valuable form of aquaculture production worldwide but, to our best knowledge, no life cycle assessments (LCA) have been undertaken on it. However, being a filter feeder and producing a thick shell during the growing cycle, the capacity of Manila clam to remove nutrients, carbon, nitrogen and phosphorous from the marine environment potentially has some positive effects on the environment. This study was performed in the Sacca di Goro lagoon, located in the southernmost part of the Po River Delta, in the northwestern Adriatic Sea. The LCA of clam farming from a cradle-to-gate perspective have been carried out, including the production stages as seed procuring, sowing, harvesting, depuration and packaging to obtain 1 ton of fresh ready-to-sell clams. The results show that area preparation, fuel combustion and plastic bags were the main contributors to the environmental impacts. The potential capability as a carbon sink of 1 ton of clams has been calculated and the effects on eutrophication reduction by fixing nitrogen and phosphorous in shells, with a net sequestration of 444.55 kg of CO₂, 1.54 kg of N and 0.31 kg of P per year. Full article

Long-term variations of ecological status in a Mediterranean coastal lagoon (Sacca di Goro, Northern Adriatic) were investigated, combining data on the concentration of surface sediment contaminants and on the structure of the macrobenthic community. The aim was to assess any amount of chemical contamination and check the response of the macrobenthic community to sediment contamination. Over the studied period, the sediments of the lagoon showed contamination by trace metals and organochlorine pesticides, with most of them exceeding the thresholds indicated by the Italian legislation in many samples. Contamination by polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs) instead never exceeded the threshold. The ecological status based on the macrobenthic community, evaluated through biotic indices (AMBI and M-AMBI), fell below the Good/Moderate threshold in most samples. The results indicate a possible influence of toxic compounds in sediment on benthic organisms, but most of the variability shown by the macrobenthic community is probably due to other factors. The difficulty in establishing a cause/effect relationship was due to the co-occurrence and variability of various stressors (both natural and anthropogenic) and their interactions. The methods currently used for monitoring transitional waters thus seem insufficient to disentangle the effect of pollutants and other environmental variables on the benthos. Integrated approaches (e.g., bioaccumulation and toxicity tests) are thus needed for a more precise identification of the risk posed by a high concentration of pollutants in such environments. Full article

Coastal lagoons display a wide range of physico-chemical conditions that shape benthic macrofauna communities. In turn, benthic macrofauna affects a wide array of biogeochemical processes as a consequence of feeding, bioirrigation, ventilation, and excretion activities. In this work, we have measured benthic respiration and solute fluxes in intact sediment cores with natural macrofauna communities collected from four distinct areas within the Sacca di Goro Lagoon (NE Adriatic Sea). The macrofauna community was characterized at the end of the incubations. Redundancy analysis (RDA) was used to quantify and test the interactions between the dominant macrofauna species and solute fluxes. Moreover, the relevance of macrofauna as driver of benthic nitrogen (N) redundancy analysis revealed that up to 66% of the benthic fluxes and metabolism variance was explained by macrofauna microbial-mediated N processes. Nitrification was stimulated by the presence of shallow (corophiids) in combination with deep burrowers (spionids, oligochaetes) or ammonium-excreting clams. Deep burrowers and clams increase ammonium availability in burrows actively ventilated by corophiids, which creates optimal conditions to nitrifiers. However, the stimulatory effect of burrowing macrofauna on nitrification does not necessarily result in higher denitrification as processes are spatially separated. Full article