More than 70 years of industrial production of per- and polyfluoroalkyl substances (PFAS) have resulted in their ubiquitous presence in the environment on a global scale, although differences in sources, transport and fate lead to variability of occurrence in the environment. Gull eggs are excellent bioindicators of environmental pollution, especially for persistent organic pollutants such as PFAS, known to bioaccumulate in organisms and to be deposited in bird eggs by maternal transfer. Using yellow-legged gull (Larus michahellis) eggs, we investigated the occurrence of more than 30 PFAS, including the most common chemicals (i.e., legacy PFAS) as well as their alternatives (i.e., emerging PFAS) in the Bay of Marseille, the second largest city in France. Compared to eggs from other colonies along the Mediterranean coast, those from Marseille had PFAS concentrations ranging from slightly higher to up to four times lower, suggesting that this area cannot be specifically identified as a hotspot for these compounds. We also found several emerging PFAS including 8:2 and 10:2 FTS, 7:3 FTCA or PFECHS in all collected eggs. Although the scarcity in toxicity thresholds for seabirds, especially during embryogenesis, does not enable any precise statement about the risks faced by this population, this study contributes to the effort in documenting legacy PFAS contamination on Mediterranean coasts while providing valuable novel inputs on PFAS of emerging concern. Identifying exposure in free-ranging species also participate to determine the main target for toxicity testing in wildlife. | publishedVersion

A set of laboratory experiments was conducted to assess the trapping efficiency of buoyant plastic debris by the estuarine vegetation Spartina maritima. Different hydrodynamic conditions typical of salt marshes were simulated in a hydraulic flume. These conditions included varying water levels between 40% and 90% of stem height, wind speeds up to 2 m/s, and unidirectional current velocities between 0.1 and 0.3 m/s. Moreover, three vegetation densities (small/medium/high) and nine plastic debris types varying in shape (elongated/two-dimensional/three-dimensional) and size (macro/meso) were tested. The results indicate that Spartina maritima functions as a natural trap. Specifically, the study highlights that lower surface velocities, higher stem densities, greater emergent heights, and larger debris sizes significantly enhance trapping efficiency. It was also inferred that for a Spartina maritima density comparable to that observed in marshes, the dominance of surface velocity or debris size effects on trapping efficiency is primarily dependent on debris shape. Consequently, surface velocity has a greater impact on two-dimensional elements, whereas debris size is more significant for three-dimensional elements. Finally, a preliminary trapping model was developed to integrate all the aforementioned variables. This model has the potential to enhance the accuracy of numerical predictions regarding the transport and fate of plastic debris using Lagrangian modeling, and can be further refined by incorporating additional data. | The authors acknowledge the support of the Programa de Ciencias Marinas (PCM), funded by the Ministry of Science and Innovation of the Spanish Government and the Regional Governments of Andalucía, Baleares, Canarias, Cantabria, Comunidad Valenciana, Galicia, and Murcia (PRTR-C17⋅I1). This program, part of the ThinkInAzul I + D + i Complementary Plan, has provided essential funding for this research, in line with the 2030 Agenda for Sustainable Development and the Decade of the Oceans initiative. Moreover, this research was also partially funded by PID2021-127358NB-I00-MICIU/AEI/10.13039/501100011033 and by FEDER as a way of making Europe. Finally, we express our deep gratitude to Margot Sánchez for her invaluable support and dedication throughout the development of this work.

peer reviewed | This study investigates essential (Mg, Ca, Fe, Mn, Cu, Zn, Se, Ni) and non-essential (Li, Be, Cr, Rb, Sr, Cs, Cd, Sn, Ba, and Pb) element concentrations and stable isotope (δ13C, δ15N, δ34S) compositions in feathers of Brown Boobies (Sula leucogaster) from three distinct Atlantic islands: the Archipelagos of Saint Peter and Saint Paul (SPSP), Abrolhos, and Cagarras. We aimed to investigate the ecological and environmental factors influencing these seabird populations and assess potential variations in contaminant exposure and dietary habits based on location, sex, and maturity stages. Our finding revealed significant geographical differences in trace element concentrations. The Brown Boobies from Cagarras had higher concentrations (mean ± SD, μg g-1) of Fe (29 ± 20) and Mn (0.82 ± 0.82) than those from Abrolhos (Fe: 21 ± 20; Mn: 0.24 ± 0.09) and SPSP (Fe: 15 ± 16; Mn: 0.21 ± 0.06). Tin concentrations were also higher in Cagarras (Sn: 0.02 ± 0.01) than in SPSP (Sn: 0.01 ± 0.01). Our analyses revealed significant differences in Li, Mg, Rb, and Zn concentrations between adults and juveniles. However, there were no sex-related differences in element concentrations within each locality. SIBER analyses revealed distinct dietary differences among the three Brown Boobies populations, with the Cagarras seabirds occupying a higher trophic position compared to the SPSP population. This study highlights the importance of considering different populations to understand contaminant exposure and ecological dynamics in Brown Boobies along the South Atlantic. The Cagarras population shows significantly higher contaminant levels, likely due to proximity to anthropogenic activities. These results highlight the necessity for ongoing monitoring to evaluate long-term effects on the more impacted population and to ensure seabird health and sustainability in the Atlantic Ocean.

peer reviewed | The Mediterranean seagrass species Posidonia oceanica forms extensive meadows that provide numerous ecological and economic services. Among the human activities threatening these meadows, boat anchoring causes severe degradation resulting in meadow fragmentation, exposure of the dead matte, and sediment disruption. In this study, we assessed the natural recolonisation dynamics of P. oceanica in anchoring-degraded sites focusing on both shallow and deep sites. Over two years, photogrammetry was employed to monitor recolonisation dynamics with a focus on patchs' edges expansion and storm-fragments accumulation. Our results show distinct recolonisation patterns between shallow and deep sites, with shallow patches displaying more variable dynamics of erosion and recolonisation, while deep patches showed slower but more consistent recovery. Additionally, the abundance of storm-fragments, primarily in shallow areas, suggests potential for enhanced recovery through natural trapping structures. Despite recent regulations reducing anchoring pressures, recolonisation rates remain insufficient to counteract the extent of degradation in a reasonable timespan. These findings underline the importance of designing tailored restoration strategies based on site-specific recolonisation potential: high-density transplantation with durable anchoring structures in shallow areas to withstand hydrodynamic forces, and more cost-effective solutions like iron staples in deeper areas. Additionally, the study supports the use of trapping substrates to retain storm-fragments in shallow sites to boost natural recolonisation. This approach is crucial for enhancing seagrass meadow resilience, especially within a context of climate change and increasing pressures on coastal ecosystems.

peer reviewed | The application of biosolids can improve soil fertility and crop productivity but also accompanies risks of heavy metals and antibiotics introduction. In the presence of heavy metals contamination, using arbuscular mycorrhizal fungi (AMF) is a promising strategy to enhance soil microbial community stability and plant tolerance resistance to heavy metals, and to reduce the spread of antibiotic resistance genes (ARGs). The present study investigated the impacts of AMF inoculation on soil and plant heavy metal contents, and soil microbial communities by pot experiments. The results showed that AMF inoculation significantly enhanced plant biomass, and reduced soil and plant heavy metals contents. While AMF inoculation did not alter bacterial and fungal community compositions, it increased bacterial diversity at higher biosolids concentrations. Notably, AMF inoculation enhanced microbial network complexity and increased keystone taxa abundance. Furthermore, several beneficial microorganisms with high resistance to heavy metals were enriched in AMF-inoculated soils. Metagenomic analysis revealed a reduction in the mobile genetic element (MGE) gene IS91 in AMF-inoculated soils and an increase in heavy metal resistance genes compared to soils without AMF. The possibility of reduction in MGE-mediated spread of ARGs is one of the key findings of this study. As a caution, this study also detected enrichment of few ARGs in high biosolids-amended soils with AMF inoculation. Overall, AMF inoculation could be a valuable strategy in agriculture for mitigating the environmental risks associated with biosolids, heavy metals and antibiotic resistance, thereby promoting sustainable soil management and health.

The oxidative potential (OP) of particulate matter (PM) is considered a better health metric of PM exposure than mass concentration since its value is highly dependent on PM composition. OP assays have shown different sensitivities to PM components and particle sizes. In this work, an urban-industrial mixed site with high levels of airborne Mn and Fe, due to the proximity of a ferromanganese alloy plant, was chosen to study the association between PM elements and three OP assays (ascorbic acid (AA), dithiothreitol (DTT), and 2,7-dichlorofluorescein (DCFH)) in size segregated PM samples (PM10-2.5 and PM2.5). Urban samples from a nearby area were also collected. The concentration of 39 elements in both the soluble (in a phosphate buffer aqueous solution) and insoluble fractions of PM10-2.5 and PM2.5 was determined by ICP-MS. Soluble elements were then associated with OP and local sources using Principal Component Analysis (PCA). Four sources of soluble elements have been identified in the urban-industrial site. The main factor was attributed to road traffic; although Cu and Fe, two active transition metals in OP assays, were associated to this factor, their low solubility, mainly in the coarse fraction, has led to low factor loadings of OP; the second factor was attributed to a ferromanganese plant, since it presented the highest factor loadings for soluble Mn in both PM10-2.5 and PM2.5; it was the main factor associated with OP-DTT and OP-DCFH values, mainly in the coarse fraction. Crustal material and sea salt aerosol were also identified as sources. | This work was supported by the Spanish Ministry of Science and Innovation (Project PID2020-114787RB-I00, funded by MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe”).

The global accumulation of plastic debris in marine ecosystems is continually increasing. Understanding the interaction between these debris and the bacterial biofilm on their surface is essential, particularly with regard to potential human pathogenic bacteria (PHPB). In this meta-analysis, we re-evaluated 16S rRNA metabarcoding data from 35 plastisphere-related studies, published up to late 2022. We compared the bacteriomes of plastics and other marine substrates, identifying PHPB associated with each type of substrate. PHPB were enriched in the plastisphere compared to the surrounding water but did not appear more abundant nor richer in than in other marine solid substrates. Nevertheless, we described a distinctive PHPB signature associated with plastics, including Vibrionaceae bacteria (5 % of the whole plastisphere) and biomarkers such as Staphylococcus haemolyticus. The contribution of other marine substrates to plastic PHPB was quantified and we found that shell and wood substrates were potential sources of PHPB for plastics. Our results suggest that both plastics and other marine solid substrates could serve as reservoirs for PHPB. However, plastics convey specific PHPB communities, and due to their ubiquity and persistence in marine ecosystems, plastic debris poses a higher risk as fomites compared to other substrates.

International audience | Bisphenol A (BPA) poses longstanding environmental concerns due to its widespread presence and recognized toxicity; however, its multigenerational ecotoxicity, in aquatic models such as water fleas, remains incompletely understood. This study examined the impact of sublethal BPA exposure on Daphnia magna across six generations, tracking changes in both life-history and population traits. Over the first five generations, BPA exposure produced minor and inconsistent effects on age at first oogenesis, age at first offspring production, growth rate, and fertility. The sixth generation exhibited prolonged oogenesis, delayed first offspring production, reduced body size, and decreased fertility, indicating delayed adverse effects. These multigenerational effects did not significantly alter population size or dynamics. Furthermore, BPA exposure did not affect feeding behavior in D. magna over six days, suggesting that food consumption-mediated mechanisms were unlikely a contributing factor. Our findings reveal BPA's delayed adverse effects on D. magna fitness, underscoring potential vulnerabilities for D. magna and other species under additional environmental stressors. These results support literature indicating that endocrine-disrupting chemicals can cause delayed and cumulative adverse effects on zooplankton descendants. Broadening multigenerational research to include a wider range of species, alongside sub-organismal analyses, is crucial to advancing regulatory frameworks and understanding underlying mechanisms.

International audience | Tillandsia genus belongs to the Bromeliaceae family plants and some species display active or passive biomonitoring capacities in their natural habitat as it has been described mostly in the American continent. However, Tillandsia aeranthos (Loisiel.) Desf. and Tillandsia bergeri Mez have never been studied for their metal air pollution biomonitor potential. A recent study conducted in our laboratory brought to light the maximum capacity of elements bioconcentration into these two species leaves. The aim of the present study is to determine if T. aeranthos and T. bergeri acclimated to Southern/European region are good biomonitors for airborne elements pollution. Twelve elements were chosen to evaluate the biomonitoring potential (As, Ba, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sn, Ti and Zn). After sampling, the content of the twelve elements in leaves was measured by Inductively Coupled Plasma-Optical Emission Spectrometry and Inductively Coupled Plasma-Mass Spectrometry. Data sets were treated according to sampling sites by box plots over time and Principal Component Analysis. The results showed differences between the two species, with T. bergeri possessing a higher capacity in accumulating elements than T. aeranthos. Fe, Zn and Co showed a higher contribution in the accumulation process in the two Tillandsia species leading to the hypothesis of a good affinity of the two species with these elements. Values obtained for five elements (As, Cr, Ni, Pb and Zn) were compared with values recorded by a monitoring station close to sampling sites showing the efficiency of these two Tillandsia species as biomonitors. High Co accumulation rates obtained in both Tillandsia species were particularly intriguing but could not be rationalized as this metal is not currently monitored by air pollution station in this region. T. aeranthos and T. bergeri proved their efficiency for the biomonitoring of elements air pollution, especially for Co, Fe and Zn.