Multiple anthropogenic pressures can lead to physiological alterations or damages to birds, potentially resulting in cascading effects on individual's fitness and population dynamics. Cavity-nesting birds, such as the great tit (Parus major), provide an excellent model for investigating the effects of environmental stressors on avian species. Their territorial behaviour and the accessibility of their nests make great tits particularly suitable for investigating the environmental conditions of their nesting locations. This study aimed to evaluate the ecotoxicological status of great tit populations inhabiting areas with different anthropogenic impacts, using a multi-biomarker approach. During the breeding seasons of 2021 and 2022, blood and excreta samples were collected from 198 nestlings belonging to 44 nests across four different areas of the Veneto region (northern Italy), representing wood (14 nests), urban (9 nests) and agricultural (9 and 12 nests) environments. Immunotoxicity, oxidative status, genotoxicity and neurotoxicity responses were evaluated on blood, while porphyrins levels on excreta. Results revealed significant physiological alterations in nestlings from urban and agricultural areas (oxidative status modifications, immune response impairments and genotoxic effects), likely associated with environmental stressors typical of anthropized ecosystems. The wood area presented elevated protoporphyrin levels, suggesting unexpected exposure to diffuse airborne particulate matter from nearby cities. The IBR index revealed that populations inhabiting urban and agricultural environments suffered the highest physiological stress. This multi-biomarker approach has proved to be a valid tool for assessing the ecotoxicological status of the great tit populations exposed to different stressors, allowing to be proposed for the conservation of wild bird species.

Apex predators are particularly vulnerable to environmental stressors due to their high trophic position. Understanding both exposure and physiological impacts is essential to support the long-term success of conservation efforts. We investigated contaminant levels and health indicators in a recently reintroduced osprey Pandion haliaetus population in Central Italy, a top predator in aquatic food-webs. From 2015 to 2022, we applied a standardized, multidisciplinary monitoring framework to 55 wild-born osprey chicks, integrating non-destructive blood and feather sampling with trace element and POPs analyses, genotoxicity biomarkers, biological and behavioral metrics (e.g., sex, morphometrics, GPS-tracked adults' space use). Among trace elements, Se showed the highest blood concentrations (4.5 ± 2.1 mg/kg dw), while Cu predominated in feathers (11.5 ± 2.7 mg/kg dw); both Cd and Pb were consistently low. Hg and Se showed significant differences among breeding sites. Significant positive correlations were observed in blood for HgSe, HgPb, PbSe, and in feathers for CdCu. A low frequency of micronuclei (0.4 ± 1.1 ‰) was observed, with lobed nuclei accounting for 81 % of observed abnormalities (mean: 26.5 ± 24.1 ‰). Hematological profiles were dominated by heterophils, followed by lymphocytes, eosinophils, monocytes, and basophils, with a mean heterophil-to-lymphocyte ratio of 1.3 ± 0.6 and thrombocyte counts averaging 246.1 ± 132.9 ‰. The most abundant POPs were PCB153 > PCB138 > PCB180 > PCB149 + 118 > PCB187, which together accounted for almost 40 % of total PCBs on average, confirming multi-year exposure in nestlings. Among DDTs, pp'DDE alone constituted between 15 % to 63 % of the total DDTs. We highlight the importance of integrative biomonitoring for assessing environmental quality and health in this critically endangered population, offering new insights into contaminant dynamics in reintroduced top predators and emphasizing the need for long-term, ecotoxicologically informed conservation strategies.

Freshwater ecosystems are crucial for biodiversity conservation, pollution mitigation and climate regulation. However, anthropogenic pressures, including agricultural and industrial activities and urbanisation, degrade water quality and ecological status. This study assessed the health of the Elsa River, a tributary of the Arno in Tuscany (Italy), through an integrated and holistic methodology combining chemical, ecological and ecotoxicological parameters. Water quality (nitrate, phosphate, ammonium concentrations and pH) was assessed through a citizen science project. This initiative actively involved local communities and high schools, fostering the sharing of local knowledge to identify sampling sites and address territorial challenges. Ecological status was assessed using the Extended Biotic Index (EBI) and Fluvial Functionality Index (FFI). Italian chubs (Squalius squalus) were employed as bioindicators to investigate microplastic ingestion, contaminant levels (heavy metals, organochlorines) and a battery of biomarkers for evaluating genotoxic, neurotoxic effects, oxidative stress, metabolic stress and the presence of polycyclic aromatic hydrocarbon (PAH) metabolites. The results showed a progressive decline in water quality and ecological status from upstream to downstream, particularly after the urbanised area and the river park, where microplastic ingestion in fish peaked at 2.5 items/individual. A genotoxic effect was highlighted, significantly correlated with the presence of mercury, polychlorinated biphenyls and benzo(a)pyrene's metabolites. This holistic approach, integrating physico-chemical analysis, ecological assessments and ecotoxicological effects on biota, provided a comprehensive understanding of the river's health. It enabled the identification of contaminants and hypothesised their sources, like illegal urban waste disposal, vehicular traffic and polluted tributaries.

This study investigates the contamination of per- and polyfluoroalkyl substances (PFAS) and organochlorine pesticides (OCPs) in eggs of great tits (Parus major) from urban, agricultural, and woodland areas from Italy. PFOS was the most prevalent PFAS, followed by long-chain perfluorocarboxylic acids (PFCAs). Agricultural areas showed the highest PFOS concentrations, while woodland areas exhibited higher concentrations of PFUnDA and PFTrDA. The observed PFCA chain length patterns across different locations highlight the influence of atmospheric chemistry, especially the oxidative breakdown of PFCA precursors, in determining contamination profiles. OCP contamination was dominated by DDT metabolites, especially p,p′-DDE, with higher concentrations in urban areas, reflecting historical pesticide use and the limited soil disturbance in these environments, which prevents the dilution and breakdown of persistent compounds like DDT. Agricultural areas showed elevated PFOS concentrations, likely due to the use of biosolid fertilizers. Principal component analysis revealed distinct contamination patterns across the studied environments, with urban and agricultural areas influenced by local sources, while woodland areas exhibited contamination linked to atmospheric deposition. These results highlight the persistence of both PFAS and OCPs in the environment, underscoring the need for continued monitoring and the utility of great tit eggs as effective bioindicators for assessing the impact of historical and ongoing pollution sources.

Temporal trends of contaminants represent an important tool to evaluate the effectiveness of chemical restriction measures. In this work, 50 eggs of Adèlie penguin (Pygoscelis adeliae) collected along the Ross Sea coasts from 1997 to 2021 were analysed for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), perfluoroalkyl substances (PFAS). Some PCB congeners showed a significantly decreasing trend, whereas HCB and p,p'-DDE indicated decreasing but not significant trends, potentially related to the unintentional production of HCB and ongoing use of DDT, even if a contribution from climate-driven remobilisation mechanisms may also play a role. PBDE-47 also indicated a decreasing but not significant trend, which might be explained by the more recent global restriction. PFAS trends agreed with what has been previously observed in the Arctic, i.e. significantly decreasing perfluorooctane sulfonate (PFOS) according to its global ban and increasing long-chain perfluorinated carboxylic acids (PFCAs). Correlations with selected climate parameters showed an association between PBDE-47 and sampling year precipitations. To our knowledge, this work represents the longest time trend study of pollutants in penguins from the Ross Sea and the first one reporting PFAS. It highlights the importance of global regulations for the contaminant developments in polar ecosystems.

The Ross Sea Marine Protected Area (RS-MPA) hosts endemic species that have to cope with multiple threats, including chemical contamination. Adèlie penguin is considered a good sentinel species for monitoring pollutants. Here, 23 unhatched eggs, collected from three colonies along the Ross Sea coasts, were analysed to provide updated results on legacy pollutants and establish a baseline for newer ones. Average sum of polychlorinated biphenyls (∑PCBs) at the three colonies ranged 20.9-24.3 ng/g lipid weight (lw) and included PCBs IUPAC nos. 28, 118, 153, 138, 180. PCBs were dominated by hexachlorinated congeners as previously reported. Hexachlorobenzene (HCB) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) ranged between 134 and 166 and 181-228 ng/g lw, respectively. Overall, ∑PCBs was exceeded by pesticides, contrary to previous studies from the Ross Sea. Sum of polybrominated diphenyl ethers (∑PBDEs) ranged between 0.90 and 1.18 ng/g lw and consisted of BDE-47 (that prevailed as expected, representing 60-80 % of the ∑PBDEs) and BDE-85. Sum of perfluoroalkyl substances (∑PFAS) ranged from 1.04 to 1.53 ng/g wet weight and comprised five long-chain perfluorinated carboxylic acids (PFCAs), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS) and perfluorooctanoic acid (PFOA); perfluorooctane sulfonamide (PFOSA) was also detected. The PFAS profile was dominated by PFCAs as already observed in Arctic seabirds. Mercury ranged from 0.07 to 0.15 mg/kg dry weight similarly to previous studies. Legacy pollutants confirmed their ongoing presence in Antarctic biota and their levels seemed mostly in line with the past, but with minor variations in some cases, likely due to continued input or release from past reservoirs. PFAS were reported for the first time in penguins from the Ross Sea, highlighting their ubiquity. Although further studies would be useful to increase the sample size and accordingly improve our knowledge on spatial and temporal trends, this study provides interesting data for future monitoring programs within the RS-MPA that will be crucial to test its effectiveness against human impacts.

Mercury (Hg) is a global environmental concern due to its toxicity (especially high in methylated form) and the long-range distribution of its gaseous elemental form (GEM). Hg-contaminated areas, such as abandoned mining sites, pose intrinsic difficulties for their management and heavy monitoring costs. In these environments, plant-based solutions may play a key role in the ecosystem quality assessment and support remediation strategies, combining reliability and cost-effectiveness. In this study, we adopted a biomonitoring approach by using tree rings of four different species collected in the proximity of the mining-metallurgical area of Abbadia San Salvatore, central Italy, a major former Hg mining district whose reclamation is currently in progress. Our dendrochemical analysis was aimed at identifying the historical changes of local atmospheric Hg contamination and at singling out, for the first time in the study area, other potentially toxic elements (PTEs) associated with the past mining activity. Collected cores dated back to early as 1940 and provided the temporal patterns of atmospheric Hg emission vs the produced liquid quantities, so reconstructing the historical impact of the mining site on nearby terrestrial ecosystems and resident human population. Current GEM contamination was found about twenty times lower than that of the fully operational mine periods. From a first survey on other PTEs, thallium (Tl) and lead (Pb) appeared to be potentially associated with the mining activity, thus suggesting new working assumptions for further dendrochemical analyses and for the inclusion of Pb in human biomonitoring surveys of the Mt. Amiata area, actually not present in the control list. The results prompt a more thorough assessment by tracking for a longer time span a critical site that is an ideal open-field lab to study the ecophysiology of different tree species in relation to environmental behavior of PTEs for better-assessing wildlife and human exposures.

In this study, leaves of the evergreen holm oak Quercus ilex were used to assess airborne contamination of potentially toxic elements (PTEs) at five towns located on the slopes of the Mt. Amiata (central Italy), an area with a long history of mining and, more recently, an important district for the industrial exploitation of geothermal energy. PTE composition and covariance of washed and unwashed Q. ilex leaves of three different ages (6, 12 and 24 month-old) were used to identify atmospheric inputs of PTEs at residential areas, evaluate long-term adsorption and retention of PTEs by the leaves, thus providing an indication of potential human exposure. Moreover, the determination of foliar concentrations of major elements (C, N, S and P) allowed an assessment of the nutritional status of the investigated urban tree stands which excluded the existence of stress condition caused by air pollution or other disturbances. Results indicated that overall Pb, Cu, and Cd concentration were low in the investigated urban sites, if compared with similar studies conducted in larger Italian cities, denoting a low contribution of vehicular traffic to the atmospheric pathway. The five urban settlements were characterized by a specific profile of elements (Al, Ba, Hg and Sb) enriched in unwashed leaves, resulting from the distinct geochemical characteristics of the area and from diffuse (i.e., urban activity) and point sources of PTEs emission (i.e., brownfields, geothermal power plants). The latter sources primarily govern the distribution of Hg, whose contamination was found to be very localized close to a major abandoned mining area. Our data provided quantitative evidence of the spectrum of PTEs potentially impacting resident population and may prove useful in support of follow-up instrumental monitoring campaigns of air quality, as well as for human health and ecological risk assessments.

Dolphin–fishery interaction is a worldwide issue affecting dolphins through bycatch and fishers through catch or gear damages. Concerning the Mediterranean Sea, problematic interactions mainly occur between common bottlenose dolphin and small-scale fisheries. Acoustic Deterrent Devices such as pingers, are one of the most widespread measures used in attempts to face this issue. Therefore, the efficiency of interactive pingers (DiD01) in protecting the trammel nets from dolphin interactions was assessed in the Northern Tyrrhenian Sea. From March to October 2021, a total of 139 fishing trials using nets with pingers (TEST) and without pingers (CTRL), respectively n = 97 and n = 42, were carried out. Non-parametric statistic of the Catch per Unit Effort, comparing control and test nets, was not significantly different ( p > 0.05) using catches weights (CPUE W ) while it was significant ( p < 0.01) considering the number of individuals (CPUE N ). Moreover, richness and relative abundance of species resulted statistically higher in test nets ( p < 0.05). This finding suggests that the absence of dolphin in the neighbourhood of fishing areas thanks to the use of pingers increases the diversity of target species. Catch damages caused by dolphins were statistically higher in nets without pinger than in nets with pinger ( p < 0.05). No dolphin bycatch was recorded during fishing operations.

Lichens play an important role in the biogeochemical cycling of mercury (Hg) and are commonly used as indicators of Hg enrichment in remote and anthropogenically impacted environments. To assess their capacity for Hg uptake and accumulation, we determined the concentration of gaseous elemental mercury (GEM) in air and the concentration of total Hg (THg) in transplanted thalli of two lichen species. Lichen transplants and passive air samplers (PASs) were concurrently deployed, side by side, at 10 sites within an abandoned mining area, characterized by large gradients in atmospheric Hg contamination. Highly variable time-weighted GEM concentrations determined by the PASs, ranging from 17 to 4,200 ng/m 3 , were mirrored by generally high Hg concentrations in transplanted thalli of both Xanthoria parietina (174-8,800 ng/g) and Evernia prunastri (143-5,500 ng/g). Hg concentrations in the two species co-varied linearly indicating about 60% greater Hg accumulation in X. parietina than in E. prunastri . Whereas Hg uptake in the fruticose E. prunastri increased linearly with GEM, a power law equation with a fractional exponent better described uptake in the foliose X. parietina . Extrapolating the relationships observed here to higher GEM levels yielded concentrations in lichen that agree very well with those measured in an earlier fumigation experiment performed under laboratory-controlled conditions. The uptake model of X. parietina was further verified by correctly estimating GEM concentrations from the THg measured in autochthonous thalli collected from the urban area adjacent to the mine site. Passive sampling can effectively provide time-weighted data of suitable spatial resolution to quantitatively describe GEM assimilation by lichens. Therefore, the combined use of passive sampling and lichen transplants can contribute to a more comprehensive understanding of the role of lichens, and potentially also of other cryptogams, in the deposition of atmospheric Hg to terrestrial ecosystems.

Leaf nutrient composition and stoichiometry reflect complex interactions of the plant with its environment and are useful traits to explore ecological processes and relationships. In the present study, the foliar elemental compositions of two common Mediterranean woody species, the evergreen broad-leaved Quercus ilex and the coniferous Pinus pinaster growing in an area of Central Italy known for geochemical and geothermal anomalies, were investigated. To assess the site-specific and age-dependent pattern of foliar composition and stoichiometry, macronutrients (C, N, P, K, Mg, S) and trace elements (Al, As, Ba, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Sb, V, Zn) were determined in leaves and needles of three different ages (6-, 12- and 24-month-old) collected from metalliferous (geothermal, mining) and rural areas. Leaves of Q. ilex showed comparatively high concentrations of micronutrients (i.e., Cu, Fe and Zn), while needles of P. pinaster accumulated significantly high concentrations of potentially toxic elements (i.e., As, Pb and S). No significant trend was found in elemental concentrations in relation to the age of leaves and needles. Multi-element stoichiometry of P. pinaster was driven by the geochemical heterogeneity of the sites, suggesting plastic adaptation at the sites with the most selective edaphoclimatic conditions (i.e., patches with nutrient poor and metalliferous soils). On the other hand, the content of both nutrients and potentially toxic elements in Q. ilex leaves varied little across the study area, reflecting stoichiometric stability; this is consistent with the ecophysiological features of Q. ilex as a late-successional species with a dominant role in the ecosystems of the Mediterranean area. Our findings demonstrate the value of foliar stoichiometric traits for understanding plant adaptation in a heterogeneous environment and also the consequences of biotic interactions during succession.

Petrochemical industries and oil refineries are sources of hazardous chemicals into the aquatic environments, and often a leading cause of reduced oxygen availability, thus resulting in adverse effects in biota. This study is an expansion of our previous work on the assessment of the BioFilm-Membrane Bioreactor (BF-MBR) to mitigate the impact of oil-polluted wastewater on marine environments. Specifically, this study evaluated the reduction of selected chemical constituents (hydrocarbons and trace metals) and toxicity related to hypoxia and DNA damage to mussels Mytilus galloprovincialis, before and after treatment of oil-polluted wastewater with the BF-MBR. The application of a multidisciplinary approach provided evidence of the efficiency of BF-MBR to significantly reducing the pollutants load from oily contaminated seawaters. As result, the health status of mussels was preserved by a hypoxic condition due to oily pollutants, as evidenced by the modulation in the gene expression of HIF-1α and PHD and changes in the level of hypotaurine and taurine. Moreover, ameliorative effects in the energy metabolism were also found in mussel gills showing increased levels of glycogen, glucose and ATP, as well as a mitigated genotoxicity was revealed by the Micronucleus and Comet assays. Overall, findings from this study support the use of the BF-MBR as a promising treatment biotechnology to avoid or limiting the compromise of marine environments from oil pollution.

EDITORIAL article Front. Mar. Sci., 26 April 2022Sec. Marine Pollution https://doi.org/10.3389/fmars.2022.899494

Lichens play an important role in the biogeochemical cycling of mercury (Hg) and are commonly used as indicators of Hg enrichment in remote and anthropogenically impacted environments. To assess their capacity for Hg uptake and accumulation, we determined the concentration of gaseous elemental mercury (GEM) in air and the concentration of total Hg (THg) in transplanted thalli of two lichen species. Lichen transplants and passive air samplers (PASs) were concurrently deployed, side by side, at 10 sites within an abandoned mining area, characterized by large gradients in atmospheric Hg contamination. Highly variable time-weighted GEM concentrations determined by the PASs, ranging from 17 to 4,200 ng/m3, were mirrored by generally high Hg concentrations in transplanted thalli of both Xanthoria parietina (174-8,800 ng/g) and Evernia prunastri (143-5,500 ng/g). Hg concentrations in the two species co-varied linearly indicating about 60% greater Hg accumulation in X. parietina than in E. prunastri. Whereas Hg uptake in the fruticose E. prunastri increased linearly with GEM, a power law equation with a fractional exponent described the uptake in the foliose X. parietina. Extrapolating the relationships observed here to higher GEM levels yielded concentrations in lichen that agree very well with those measured in an earlier fumigation experiment performed under laboratory-controlled conditions. The uptake model of X. parietina was further verified by correctly estimating GEM concentrations from the THg measured in autochthonous thalli collected from the urban area adjacent to the mine site. Passive sampling can effectively provide time-weighted data of suitable spatial resolution to quantitatively describe GEM assimilation by lichens. Therefore, the combined use of passive sampling and lichen transplants can contribute to a more comprehensive understanding of the role of lichens, and potentially also of other cryptogams, in the deposition of atmospheric Hg to terrestrial ecosystems.

In this study, the release of Cu 2+ and Zn 2+ was investigated and modeled in the epiphytic lichen Evernia prunastri. Samples were incubated with solutions containing these metals at ecologically relevant concentrations (10 and 100 μM) and then transplanted to a remote area and retrieved after 1, 2, 3, 6, 12, and 18 months. The results showed that, after 12 months, all samples faced similar metal reductions of ca. 80–85%, but after this period, all the involved processes seem to be no longer capable of generating further reductions. These results suggest that the lichen E. prunastri can provide information about environmental improvements after exposure to high or very high pollution levels in a relatively short period of time.

Mt. Amiata (1738 m) is a volcanic peak in central Italy, completely covered with native oak, chestnut and beech forests. In this Natura 2000 site of Community Importance overlying a large shallow aquifer, climate change and the long-range transport of nutrients and contaminants might have negative impacts on relict plants populations and spring water chemistry. To evaluate the atmospheric deposition of trace elements in Mt. Amiata forest ecosystems, we analyzed the elemental composition of topsoils, epiphytic lichens (Parmelia species) and epigeic moss (Hypnum cupressiforme) between 120 and 1730 m a.s.l. along the NW side of the mountain, which is scarcely affected by natural and anthropogenic sources of metals. The elemental composition of the topsoil is mainly influenced by the different lithologies of the study area (calcareous up to an elevation of 700 m, volcanic up to the summit) and only Pb concentrations increased significantly with the altitude. The total element concentrations in cryptogams, particularly net of the possible contribution from soil particles, showed an enhanced accumulation of Pb, Cd, Hg and Zn in samples collected at altitudes above 1300 m, where beech forest are frequently shrouded in clouds and fog and receive more snow and rain than the lower chestnut and oak woods. Interestingly, the older and metabolically inactive tissues at the base of moss shoots, which are usually overlooked in biomonitoring surveys, appeared to behave as long-term accumulators of Pb. The possible mechanisms involved in the increased bioaccumulation of Mn in cryptogams inhabiting chestnut woods are discussed.

This study investigated the dynamics of the accumulation and release of Hg2+ in lichens, using Evernia prunastri (L.) Ach. as a model species. Thalli were incubated with solutions containing 1, 10, and 100 µM Hg2+ and then exposed for 1, 2, 3, 6, 12, 18, and 24 months at the Botanical Garden of the University of Siena (a location free from local Hg sources). Lichen samples accumulated Hg proportionally to the exposure concentration, and after the exposure, reductions over time were evident, already starting from 1–2 months. After 24 months, samples released 72–74 (healthy thalli) to 94% (unhealthy thalli) of the accumulated Hg, but control values of untreated samples were never reached. Depending on the Hg content after the exposure, stable decreased concentrations were reached after 6–24 months. The results of this study highlight the ability of the lichen E. prunastri to reflect rapidly increasing environmental Hg concentrations, as well as to indicate an ameliorated situation (e.g., the closure of an Hg source). However, we have found evidence that an acute pollution episode can influence the content of Hg in lichens for several years.

This study investigated the uptake and release of Cu ions in the epiphytic lichen Evernia prunastri, a species widely used to monitor trace metal pollution. A cross transplant experiment from a background area to a polluted one and then back to an unpolluted one was simulated by incubating lichen thalli with 10 and 100 µM Cu2+ solutions and subsequently in deionized water to induce metal release. The working hypothesis was that after the accumulation of Cu ions, a forced release brings the concentration back to the original values. Copper treatment caused a significant uptake, proportional to the concentrations in the solution. Accumulation occurred mostly extracellularly (90% after incubation with Cu 10 µM and 60% with Cu 100 µM). The subsequent induced release was evident only in samples treated with 100 µM, and was determined by the loss from intracellular compartments. Lichen vitality, expressed in terms of photosynthetic efficiency, was not affected by Cu treatment. It is concluded that while ionic uptake is a fast process, metal release requires a much longer time. In addition, it is confirmed that the cell wall is a buffer between the outer environment and the cell interior.

Arctic regions are inhabited by cold-adapted stenothermal or eurythermal species. Unlike in the Antarctic, eurythermal species predominate, because of opportunities for migrations to temperate latitudes. In the Antarctic sea, the modern chondrichthyan genera are scarcely represented. In contrast, in the Arctic, sharks and skates are present with about 8% of the species

Due to its peculiarity to accumulate environmental contaminants, the osprey Pandion haliaetus is a sentinel species for the biomonitoring of contaminants in aquatic ecosystems. Despite this, no information on trace element concentration exists for the Mediterranean area, where relict and vulnerable osprey populations exist. We evaluated the geographical patterns of heavy metals and selenium in osprey eggs from three different populations of the Mediterranean basin (Balearic Islands, Corsica, and Tuscany), to identify any possible contaminant sources. Pattern of metal concentration followed the order: Fe > Zn > Cu > Se > Hg > Pb > Cd. Differences in contaminant concentrations between habitats and among egg components were found. Egg content and inner membrane showed higher mercury levels (1.06 ± 0.89 and 0.67 ± 0.62 mg/kg dw, respectively) than those recorded in the eggshell. Mercury concentration was ca. two times higher in marine than in wetland samples, and even higher (3.6 times) when referred to the eggshell. Cu, Fe, Zn, and Se had higher concentration in the inner membrane. We stress how the choice of the biological material can have significant implications for the correct evaluation of contamination. Our study represents a first regional scale survey for the vulnerable Mediterranean osprey populations and provides baseline data for their long-term biomonitoring.