Honey bees and the pollination services they provide are fundamental for agriculture and biodiversity. Agrochemical products and other classes of contaminants, such as trace elements and polycyclic aromatic hydrocarbons, contribute to the general decline of bees’ populations. For this reason, effects, and particularly sublethal effects of contaminants need to be investigated. We conducted a review of the existing literature regarding the type of effects evaluated in Apis mellifera, collecting information about regions, methodological approaches, the type of contaminants, and honey bees’ life stages. Europe and North America are the regions in which A. mellifera biological responses were mostly studied and the most investigated compounds are insecticides. A. mellifera was studied more in the laboratory than in field conditions. Through the observation of the different responses examined, we found that there were several knowledge gaps that should be addressed, particularly within enzymatic and molecular responses, such as those regarding the immune system and genotoxicity. The importance of developing an integrated approach that combines responses at different levels, from molecular to organism and population, needs to be highlighted in order to evaluate the impact of anthropogenic contamination on this pollinator species.

The aim of this study was to evaluate a set of ecotoxicity biotests on three marine model species exposed to elutriates of marine sediments inoculated with the biodegradable plastic Mater-Bi or with cellulose. The sediments were incubated at 28°C and tested after 6 months, when clear signs of degradation were visible in the exposed samples, and after 12 months, when the samples had completely disappeared. The model organisms selected for the study were the unicellular algae Dunaliella tertiolecta, the sea urchin (Paracentrotus lividus) and sea bass (Dicentrarchus labrax) juveniles. The unicellular algae and sea urchins were used to determine the toxicological endpoint of growth inhibition and embryotoxicity, respectively, and the sea bass juveniles were tested to evaluate sublethal effect endpoints using lipid peroxidation and genotoxicity biomarkers. Elutriates of sediment inoculated with Mater-Bi for 6 and 12 months showed an absence of toxic effects in all of the model organisms exposed in this study. The Mater-Bi degradation process did not generate or transfer into the elutriates toxic substances that could cause alterations in the growth of D. tertiolecta, in the P. lividus embryo-toxicity assay or in the sensitive biomarker responses of the fish D. labrax. The tested species are considered to be representatives of different levels of the marine trophic chain. The results obtained in this study suggest that the ecotoxicological approach applied may be suitable for investigating the environmental impact of the degradation of bioplastics in marine sediments.

Fungi are an essential component of marine ecosystems, although little is known about their global distribution and underwater diversity, especially in sediments. Microplastics (MPs) are widespread contaminants worldwide and threaten the organisms present in the oceans. In this study, we investigated the fungal abundance and diversity in sediments, as well as the MPs, of three sites with different anthropogenic impacts in the Mediterranean Sea: the harbor of Livorno, the marine protected area “Secche della Meloria”; and an intermediate point, respectively. A total of 1526 isolates were cultured and identified using a polyphasic approach. For many of the fungal species this is the first record in a marine environment. A comparison with the mycobiota associated with the sediments and MPs underlined a “substrate specificity”, highlighting the complexity of MP-associated fungal assemblages, potentially leading to altered microbial activities and hence changes in ecosystem functions. A further driving force that acts on the fungal communities associated with sediments and MPs is sampling sites with different anthropogenic impacts.

The principal aim of the present study was to develop and apply novel ex vivo tests as an alternative to cell cultures able to evaluate the possible effects of emerging and legacy contaminants in Caretta caretta. To this end, we performed ex vivo experiments on non-invasively collected whole-blood and skin-biopsy slices treated with chrysene, MEHP, or PBDE-47. Blood samples were tested by oxidative stress (TAS), immune system (respiratory burst, lysozyme, and complement system), and genotoxicity (ENA assay) biomarkers, and genotoxic and immune system effects were observed. Skin slices were analyzed by applying a 2D-PAGE/MS proteomic approach, and specific contaminant signatures were delineated on the skin proteomic profile. These reflect biochemical effects induced by each treatment and allowed to identify glutathione S-transferase P, peptidyl-prolyl cis-trans isomerase A, mimecan, and protein S100-A6 as potential biomarkers of the health-threatening impact the texted toxicants have on C. caretta. Obtained results confirm the suitability of the ex vivo system and indicate the potential risk the loggerhead sea turtle is undergoing in the natural environment. In conclusion, this work proved the relevance that the applied ex vivo models may have in testing the toxicity of other compounds and mixtures and in biomarker discovery.