Microplastics (MPs) pose an increasing and significant threat to marine biodiversity and there is a current need to determine the effects of exposure on benthic sessile invertebrates. This study examines the filtration capacity and retention of MP particles, as well as their physiological impacts in the marine sponge Spongia officinalis, a bioindicator species. The findings revealed a very high filtration capacity for MPs within the size range of 1-5 μm, along with a rapid turnover rate, as a large portion of particles were expelled within 48 h of exposure. Histological analyses detected MP particles within the cellular structures of the analyzed tissues, indicating that MPs of this size can penetrate cellular barriers. In terms of physiological effects, detoxification activity was activated during the depuration phase, and lipid peroxidation was observed during both the exposure and depuration phases. Overall, this study provides critical insights into the filtration and retention capacity, intercellular integration of MP particles, and the physiological effects of MP exposure in S. officinalis, providing a baseline for future research.

Thousands of tire rubber particles (TPs) enter the marine environment every year, contributing to microplastic pollution. The toxicity of TPs can be related to the particles themselves or chemical additives, which can leach into seawater and potentially affect marine organisms. The current study presents new insights into TPs' impact on marine organisms' reproductive processes. The leachates of end-of-life TPs and their adverse effects on gamete quality were evaluated by analysing the chemical compositions of seawater leachates and several gamete physiological parameters, taking the mussel Mytilus galloprovincialis as a model. Chemical analyses revealed the leaching of different metals, among which zinc showed the highest level (∼3 mg/L). Organic compounds such as antioxidants, vulcanising and protective agents were annotated in leachates and correlated with the observed harmful effects on the reproductive process. The exposure of oocytes and spermatozoa to TP leachates negatively affects the gamete quality by increasing the mitochondrial activity in both gamete types and decreasing the motility of spermatozoa, which may impair the reproductive success of mussels. Since reproductive success is a key factor in species survival, this study highlights the urgent need to extend the presented research to other marine organisms.

Heavy metal (HM) contamination represents a significant threat to soil functionality and ecosystem health. The present study aims to assess the efficacy of an integrated bioremediation strategy combining Lavandula angustifolia (lavender) and a four-strain bacterial consortium in restoring a multi-contaminated soil collected from a former industrial site in Southern Italy. Microcosm experiments were conducted over a period of 90 days, including three treatments and a control: a planted condition (PLANT), a bioaugmented condition (BIOAUG), and a combined plant and bioaugmentation condition (PLANT+BIOAUG). The control (HCS) consisted of unplanted and non-bioaugmented soil. Soil physico-chemical parameters (e.g., pH, electrical conductivity, and heavy metal concentrations), plant growth, microbial abundance, and dehydrogenase activity (DHA) were measured at the initial and final experimental time. Finally, a Soil Quality Index (SQI) was applied. The combined treatment (PLANT+BIOAUG) promoted a significant reduction in total Pb and Sn concentrations by 44.7% and 66.9%, respectively. Moreover, a significant increase in soil pH and microbial abundance was observed. Applying the SQI to integrate overall soil data made it possible to highlight the highest quality score (0.73) for this condition. These findings suggest the potential effectiveness of lavender-assisted bioaugmentation as a scalable and multifunctional strategy for remediating heavy metal-contaminated soils, in line with ecological restoration principles.