The Anthropocene is characterized by dramatic ecosystem changes driven by human activities. The impact of these activities can be assessed by different geochemical and paleontological proxies. However, each of these proxies provides only a fragmentary insight into the effects of anthropogenic impacts. It is highly challenging to reconstruct, with a holistic view, the state of the ecosystems from the preindustrial period to the present day, covering all biological components, from prokaryotes to multicellular eukaryotes. Here, we used sedimentary ancient DNA (sedaDNA) archives encompassing all trophic levels of biodiversity to reconstruct the two century-natural history in Bagnoli-Coroglio (Gulf of Pozzuoli, Tyrrhenian Sea), one of the most polluted marine-coastal sites in Europe. The site was characterized by seagrass meadows and high eukaryotic diversity until the beginning of the 20th century. Then, the ecosystem completely changed, with seagrasses and associated fauna as well as diverse groups of planktonic and benthic protists being replaced by low diversity biota dominated by dinophyceans and infaunal metazoan species. The sedaDNA analysis revealed a five-phase evolution of the area, where changes appear as the result of a multi-level cascade effect of impacts associated with industrial activities, urbanization, water circulation and land-use changes. The sedaDNA allowed to infer reference conditions that must be considered when restoration actions are to be implemented.

The evaluation of the effects of pollution (e.g., Hg pollution) is a difficult task and relies mostly on biomonitoring based on bioindicators. The application of biomarkers may represent a complementary or alternative approach in environmental biomonitoring. Mercury is known to pose a significant health hazard due to its ability to cross cellular membranes, bioaccumulate, and biomagnify. In the present research, the effects of short-term (i.e., 24 h) Hg exposure in the symbiont-bearing benthic foraminiferal species Amphistegina lessonii are evaluated using several biomarkers (i.e., proteins and enzymes). Mercury leads to significant changes in the biochemistry of cells. Its effects are mainly associated with oxidative stress (i.e., production of reactive oxygen species: ROS), depletion of glutathione (GSH), and alteration of protein synthesis. Specifically, our findings reveal that exposure to Hg leads to the consumption of GSH by GPx and GST for the scavenging of ROS and the activation of antioxidant-related enzymes, including SOD and GSH-enzymes (GST, GSR, GPx, and Se-GPx), that are directly related to a defense mechanism against ROS. The Hg exposure also activates the MAPK (e.g., p-p38) and HSP (e.g., HSP 70) pathways. The observed biochemical alterations associated with Hg exposure may represent effective and reliable proxies (i.e., biomarkers) for the evaluation of stress in A. lessonii and lead to a possible application for the detection of early warning signs of environmental stress in biomonitoring.

This study investigates the ecotoxicological effects of BDE-209, a persistent organic pollutant (POP) prevalent in Kuwait's coastal-industrial areas, on benthic foraminiferal communities. We conducted a mesocosm experiment in which we exposed benthic foraminiferal communities sampled from the coastal-industrial areas of Kuwait to a gradient of BDE-209 concentrations (0.01 to 20 mg/kg). The impact of exposure was assessed using live-staining and metabarcoding techniques. Despite the significantly different taxonomic compositions detected by the two techniques, our results show that BDE-209 significantly affects foraminiferal communities, with moderately high concentrations leading to reduced α-diversity and considerable taxonomic shifts in both molecular and morphological assemblages. At concentrations of 10 and 20 mg/kg, no living foraminifera were detected after 8 weeks, suggesting a threshold for their survival under BDE-209 exposure. The parallel responses of molecular and morphological communities confirm the reliability of both assessment methods. This study is the first to investigate the reaction of eukaryotic communities, specifically foraminifera, to POPs such as BDE-209, generating valuable insights that have the potential to enhance field studies and aid the refinement of sediment quality guidelines.

A 300-year paleoenvironmental reconstruction using benthic foraminifera in the Gulf of Gaeta (central Tyrrhenian Sea, Italy) is here presented. The Gulf of Gaeta dynamics are strongly influenced by the fluvial input, particularly the Volturno River and human activities. The sedimentary archive reveals a strong relation between the variations in the composition of the benthic foraminiferal assemblages and human interventions in the Volturno coastal area. According to the statistical analysis, three main temporal phases are identified and supported by the variations in the enhanced benthic foraminifera oxygen index (EBFOI) values over time. We hypothesize that the main environmental modifications might be ascribed to the construction of two dams, Sorgente Capo Volturno (1909–1916) and Ponte Annibale (1953–1958). The dams have probably altered the supply of sediments causing a physical stress related to the variations in grain-size, the organic matter and the oxygen availability. This temporal reconstruction further supports the ability of foraminifera to register paleoenvironmental changes induced by human activities such as the modification of the physical environment within the sedimentary record.

The former-industrial site of Bagnoli (Naples, Southern Italy), the second Italian largest steelwork, has been negatively affected by the discharges of heavy metals and hydrocarbons that have markedly altered the water and sediment quality as well as the biota living therein. On the basis of benthic foraminiferal traditional morphology-based approach and eDNA metabarcoding, we evaluate the response of benthic foraminifera to pollution and define the Ecological Quality Status (EcoQS) in Gulf of Bagnoli. Higher concentrations of Pb (up to 322 ppm) and Zn (up to 795 ppm) than Effect Range Median are identified in the area in front of the former industrial site, specifically between the two piers. Indeed, significant differences in terms of alpha and beta diversity have been found between the most polluted area (i.e., in front of the former industrial plant) and the sites in the northern area that can be considered relatively low polluted. The analysis of selected biotic indices (i.e., exp(H’_bc), Foram-AMBI, gAMBI) computed for the morphological and metabarcoding datasets strikingly and congruently identify poor to bad EcoQS in the polluted area in front of the former industrial plant, whereas the EcoQS results good to high North to the site. The congruence and complementarity between metabarcoding and morphological data support the application of foraminiferal metabarcoding in routine biomonitoring as a reliable, time- and cost-effective methodology to assess the environmental impacts of heavily polluted marine areas.