Retrospective biomonitoring of chemical contamination in the marine coastal environment of Terra Nova Bay (Ross Sea, Antarctica) by environmental specimen banking

Source apportionment of major ions and trace metals in the lacustrine systems of Schirmacher Hills, East Antarctica

The fabric of the Antarctic lacustrine system has a crucial role in assimilating the anthropogenic inputs and mitigating their long time impacts on climate change. Here, we present the changes in the concentrations of major ions and trace metals in the surface water of the lacustrine system to understand the extent of anthropogenic impacts from the adjacent Schirmacher Hills, East Antarctica. The results show that the land-locked lakes (closed-basin lakes surrounded by topographical barriers such as mountains or bedrock formations) in the region have a moderate enrichment in elemental concentrations compared to the pro-glacial lakes (marginal freshwater bodies that form at the terminus of a glacier or ice sheet). The water quality index (WQI: 7.58-12.63) and pollution evaluation index (PEI: 1.36-2.35) remained normal, indicating that the water in these lake are of good quality. However, a significant correlation between lithogenic elements (Al, Fe) and potentially toxic elements (Cd, Cr, and Ba), suggests an increase in the anthropogenic impacts. Based on the principal component analysis (PCA), the source of trace metals to the lacustrine systems appears to be the surrounding environment, followed by aerosol dust particles. Hierarchical cluster analysis (HCA) revealed that regional topography significantly impacts the supply of major ions/trace metals to these lakes. The present study provides baseline data and can be used to estimate and forecast future local and/or global anthropogenic contaminations in the lacustrine system of Schirmacher Hills, East Antarctica. Moreover, the presence of research stations (Maitri and Novolazarevskaya), tourist activities, and the potential for anthropogenic stressors necessitate continued monitoring and impact assessment programs within the Schirmacher Hills lacustrine systems. These programs are crucial for safeguarding this pristine ecosystem from future environmental disturbances under a changing Antarctic climate, as mandated by the Antarctic Treaty System and the Indian Antarctic Act.

The assessment of bioavailability and environmental risk of dissolved and particulate polycyclic aromatic hydrocarbons in the seawater of typical bays

The pollution of dissolved and particulate polycyclic aromatic hydrocarbons (PAHs) in coastal waters has been increasing in recent decades. However, limited research has been conducted on the characteristics of dissolved and particulate PAHs in seawater and their associated risk assessment. Here, we focused on the bioavailability and environmental risk of PAHs in four typical bays of Shandong Province, China, and used scallop Chlamys farreri and clam Mactra veneriformis as sentinel species. The results revealed that dissolved PAHs tended to bioaccumulate in scallop C. farreri, and their ecological risk exhibited a significant correlation with the health risk of bioaccumulated PAHs and the bioeffect of screened biomarkers in scallop. Conversely, particulate PAHs demonstrated a higher bioaccumulation potential in the clam M. veneriformis, showing a stronger correlation between their ecological risk, health risk, and bioeffect in clams. This study provides the first elucidation of the connection between the ecological risk, health risk, and bioeffect of PAHs. Furthermore, based on the better correlation of health risk and bioeffect caused by PAHs with total PAHs in seawater, we propose that the clam M. veneriformis is a more suitable sentinel species for assessing environmental risk in typical bays of Shandong Province.

The long-term spatial and temporal distributions of polychlorinated naphthalene air concentrations in Fildes Peninsula, West Antarctica

The knowledge of polychlorinated naphthalenes (PCNs) in the Antarctic atmosphere is quite limited compared to the Arctic. PCNs are a global concern because of their PBT characteristics (i.e., persistent, bioaccumulative, and toxic) and severe and often deadly biological effects on people and other animals. Therefore, the present study used a passive air sampling method to conduct long-term air monitoring of PCNs for almost a decade from 2013 to 2022, specifically on Fildes Peninsula, situated on King George Island, located in West Antarctica. The median sum of mono-CNs to octa-CN concentration (∑75PCNs) in the Antarctic atmosphere was 12.4 pg/m3. In terms of homologues, mono-CNs to tri-CNs predominated. Among these, the prevalent congeners observed were PCN-1 and PCN-2, originating from mono-CNs, followed by PCN-5/7 from di-CNs, and PCN-24/14 from tri-CNs, respectively. Between 2013 and 2022, the total levels of PCNs were found to have decreased approximately fourfold. Ratio analyses and principal component analysis (PCA) showed that the long-range atmospheric transport and combustion-related sources as the potential PCN sources in the study area. This paper provides the most up-to-date temporal trend analysis of PCNs in the Antarctic continent and is the first to document all 75 congeners (mono-CNs to octa-CN homologue groups).

Multi-benthic size approach to unveil different environmental conditions in a Mediterranean harbor area (Ancona, Adriatic Sea, Italy)

Harbors are hubs of human activity and are subject to the continuous discharge and release of industrial, agricultural, and municipal waste and contaminants. Benthic organisms are largely known to reflect environmental conditions they live in. Despite meio- and macrofauna interacting within the benthic system, they are ecologically distinct components of the benthos and as such may not necessarily respond to environmental conditions and/or disturbances in the same way. However, in a few field studies the spatial patterns of meio- and macrofauna have been simultaneously compared. In the present study, we assess the response and patterns in the abundance, diversity, and distribution of the two benthic size classes to the different environmental conditions they live in (i.e., sediment concentrations of selected trace metals and polycyclic aromatic hydrocarbons (PAHs); organic matter contents and grain size) characterizing the Ancona Harbor (Adriatic Sea). Meio- and macrofauna provided partially similar types of information depending on the indices used (univariate measures or community structure/species composition) and the different 'response-to-stress'. The community structure (i.e., taxa composition) of both benthic size components clearly showed differences among sampling stations located from inside to outside the harbor, reflecting the marked environmental heterogeneity and disturbance typically characterizing these systems. Notwithstanding, the univariate measures (i.e., meio- and macrofauna total abundance, diversity indices and equitability) didn't show similar spatial patterns. Meiofauna were likely to be more sensitive to the effects of environmental features and contaminants than macrofauna. Overall, trace metals and PAHs affected the community composition of the two benthic components, but only the meiofauna abundance and diversity were related to the environmental variables considered (i.e., quantity and quality of organic matter). Our results pinpoint the importance of studying both meio- and macrofauna communities, which could provide greater insight into the processes affecting the investigated area and reveal different aspects of the benthic ecosystems in response to harbor conditions.

Berlin statement on legacy and emerging contaminants in polar regions

Polar regions should be given greater consideration with respect to the monitoring, risk assessment, and management of potentially harmful chemicals, consistent with requirements of the precautionary principle. Protecting the vulnerable polar environments requires (i) raising political and public awareness and (ii) restricting and preventing global emissions of harmful chemicals at their sources. The Berlin Statement is the outcome of an international workshop with representatives of the European Commission, the Arctic Council, the Antarctic Treaty Consultative Meeting, the Stockholm Convention on Persistent Organic Pollutants (POPs), environmental specimen banks, and data centers, as well as scientists from various international research institutions. The statement addresses urgent chemical pollution issues in the polar regions and provides recommendations for improving screening, monitoring, risk assessment, research cooperation, and open data sharing to provide environmental policy makers and chemicals management decision-makers with relevant and reliable contaminant data to better protect the polar environments. The consensus reached at the workshop can be summarized in just two words: "Act now!" Specifically, "Act now!" to reduce the presence and impact of anthropogenic chemical pollution in polar regions by. •Establishing participatory co-development frameworks in a permanent multi-disciplinary platform for Arctic-Antarctic collaborations and establishing exchanges between the Arctic Monitoring and Assessment Program (AMAP) of the Arctic Council and the Antarctic Monitoring and Assessment Program (AnMAP) of the Scientific Committee on Antarctic Research (SCAR) to increase the visibility and exchange of contaminant data and to support the development of harmonized monitoring programs. •Integrating environmental specimen banking, innovative screening approaches and archiving systems, to provide opportunities for improved assessment of contaminants to protect polar regions.

First evidence of legacy chlorinated POPs bioaccumulation in Antarctic sponges from the Ross sea and the South Shetland Islands

Antarctica is no longer pristine due to the confirmed presence of anthropogenic contaminants like Persistent Organic Pollutants (POPs). Benthic organisms are poorly represented in contamination studies in Antarctica although they are known to bioaccumulate contaminants. Sponges (Phylum Porifera) are dominant members in Antarctic benthos, both in terms of abundance and biomass, and are an important feeding source for other organisms, playing key functional roles in benthic communities. To the best of our knowledge, legacy chlorinated POPs such as polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and dichlorodiphenyltrichloroethane (DDT) and their metabolites have never been investigated in this Phylum in Antarctica. The aim of this work was to evaluate the bioaccumulation of PCBs, HCB, o,p'- and p,p'-DDT and their DDE and DDD isomers in 35 sponge samples, belonging to 17 different species, collected along the coast of Terra Nova Bay (Adèlie Cove and Tethys Bay, Ross Sea), and at Whalers Bay (Deception Island, South Shetland Islands) in Antarctica. Lipid content showed a significant correlation with the three pollutant classes. The overall observed pattern in the three study sites was ΣPCBs>ΣDDTs>HCB and it was found in almost every species. The ΣPCBs, ΣDDTs, and HCB ranged from 54.2 to 133.7 ng/g lipid weight (lw), from 17.5 to 38.6 ng/g lw and from 4.8 to 8.5 ng/g lw, respectively. Sponges showed contamination levels comparable to other Antarctic benthic organisms from previous studies. The comparison among sponges of the same species from different sites showed diverse patterns for PCBs only in one out of four cases. The concentration of POPs did not vary significantly among the three sites. The predominance of lower chlorinated organochlorines in the samples suggested that long-range atmospheric transportation (LRAT) could be the major driver of contamination as molecules with a high long range transport potential (e.g. low chlorinated PCBs, HCB) prevails on heavier ones.

Legacy and emerging organic contaminants in the polar regions

The presence of numerous emerging organic contaminants (EOCs) and remobilization of legacy persistent organic pollutants (POPs) in polar regions have become significant concerns of the scientific communities, public groups and stakeholders. This work reviews the occurrences of EOCs and POPs and their long-range environmental transport (LRET) processes via atmosphere and ocean currents from continental sources to polar regions. Concentrations of classic POPs have been systematically monitored in air at several Arctic stations and showed seasonal variations and declining trends. These chemicals were also the major POPs reported in the Antarctica, while their concentrations were lower than those in the Arctic, illustrating the combination of remoteness and lack of potential local sources for the Antarctica. EOCs were investigated in air, water, snow, ice and organisms in the Arctic. Data in the Antarctica are rare. Reemission of legacy POPs and EOCs accumulated in glaciers, sea ice and snow may alter the concentrations and amplify their effects in polar regions. Thus, future research will need to understand the various biogeochemical and geophysical processes under climate change and anthropogenic pressures.

Occurrence and spatial distribution of trace metals in seawaters of the Drake Passage and Antarctic Peninsula

In this study, surface seawater was collected from 82 stations in the Drake Passage and Antarctic Peninsula sea area, and the distribution characteristics and correlations of 11 trace elements (i.e., V, Cr, Mn, Co, Cu, Zn, As, Mo, Cd, Pb, and U) in the seawater were analyzed. Results showed remarkable differences in the concentration of different elements, among which those of Mn (53.15%), Mo (22.77%), Zn (9.81%), and U (6.23%) were relatively high. The concentration of trace elements in Drake Passage water was relatively low, likely because a westerly drift that enhances large circulating currents exists in the sea area, thereby affecting the distribution of substances in the water. Mn, Co, Cu, Zn, Cd, and Pb showed relatively high concentrations at more stations than the other elements, and the high concentrations of Mn, Co, and Cd were mainly found in shallow water areas. UV, MoV, AsV, AsMo, AsU, and MoU demonstrated good linear correlations with correlation coefficients in the range of 0.878-0.961. These results could provide support for further explorations of the environmental behavior of trace elements in Antarctica.

Occurrence, distribution, and bioaccumulation of new and legacy persistent organic pollutants in an ecosystem on King George Island, maritime Antarctica

The occurrence and bioaccumulation of new and legacy persistent organic pollutants (POPs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), hexabromocyclododecanes (HBCDs), and Dechlorane Plus (DPs) and their related compounds (Dechloranes) in an ecosystem on King George Island, Antarctica are investigated. The new and legacy POPs were widely detected in the animal samples collected from Antarctica, which included Limpet, Antarctic cod, Amphipods, Antarctic icefish, Gentoo and Chinstrap penguins, Kelp gull, and South polar skua. The trophic magnification factors indicated that the levels of PCNs and HBCDs, as well as the legacy POPs, were magnified through the food web, whereas DPs might be diluted through the trophic levels contradicting the classification of Dechloranes as POPs. This is one of the first extensive surveys on PCNs, HBCDs, and Dechloranes, which provides unique information on the distribution and trophic biomagnification potential of the new and legacy POPs in the Antarctic region.

Legacy and Emerging Persistent Organic Pollutants in Antarctic Benthic Invertebrates near Rothera Point, Western Antarctic Peninsula

Pollutant levels in polar regions are gaining progressively more attention from the scientific community. This is especially so for pollutants that persist in the environment and can reach polar latitudes via a wide range of routes, such as some persistent organic pollutants (POPs). In this study, samples of Antarctic marine benthic organisms were analyzed for legacy and emerging POPs (polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides) to comprehensively assess their current POP concentrations and infer the potential sources of the pollutants. Specimens of five benthic invertebrate species were collected at two distinct locations near Rothera research station on the Antarctic Peninsula (67°35'8 ̋ S and 68°7'59 ̋ W). Any impact of the nearby Rothera station as a local source of pollution appeared to be negligible. The most abundant chemicals detected were hexachlorobenzene (HCB) and BDE-209. The highest concentrations detected were in limpets and sea urchins, followed by sea stars, ascidians, and sea cucumbers. The relative congener patterns of PCBs and PBDEs were similar in all of the species. Some chemicals (e.g., heptachlor, oxychlordane, and mirex) were detected in the Antarctic invertebrates for the first time. Statistical analyses revealed that the distribution of the POPs was not only driven by the feeding traits of the species but also by the physicochemical properties of the specific compounds.

Sources of elevated heavy metal concentrations in sediments and benthic marine invertebrates of the western Antarctic Peninsula

Antarctica is one of the least anthropogenically-impacted areas of the world. Metal sources to the marine environment include localised activities of research stations and glacial meltwater containing metals of lithogenic origin. In this study, concentrations of nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) were examined in three species of benthic invertebrates collected from four locations near Rothera Research Station on the western Antarctic Peninsula: Laternula elliptica (mudclam, filter feeder), Nacella concinna (limpet, grazer) and Odontaster validus (seastar, predator and scavenger). In addition, metals were evaluated in sediments at the same locations. Metal concentrations in different body tissues of invertebrates were equivalent to values recorded in industrialized non-polar sites and were attributed to natural sources including sediment input resulting from glacial erosion of local granodioritic rocks. Anthropogenic activities at Rothera Research Station appeared to have some impact on metal concentrations in the sampled invertebrates, with concentrations of several metals higher in L. elliptica near the runway and aircraft activities, but this was not a trend that was detected in the other species. Sediment analysis from two sites near the station showed lower metal concentrations than the control site 5 km distant and was attributed to differences in bedrock metal content. Differences in metal concentrations between organisms were attributed to feeding mechanisms and habitat, as well as depuration routes. L. elliptica kidneys showed significantly higher concentrations of eight metals, with some an order of magnitude greater than other organs, and the internal structure of O. validus had significantly higher Ni. This study supports previous assessments of N. concinna and L. elliptica as good biomonitors of metal concentrations and suggests O. validus as an additional biomonitor for use in future Antarctic metal monitoring programs.

Major threats of pollution and climate change to global coastal ecosystems and enhanced management for sustainability

Coastal zone is of great importance in the provision of various valuable ecosystem services. However, it is also sensitive and vulnerable to environmental changes due to high human populations and interactions between the land and ocean. Major threats of pollution from over enrichment of nutrients, increasing metals and persistent organic pollutants (POPs), and climate change have led to severe ecological degradation in the coastal zone, while few studies have focused on the combined impacts of pollution and climate change on the coastal ecosystems at the global level. A global overview of nutrients, metals, POPs, and major environmental changes due to climate change and their impacts on coastal ecosystems was carried out in this study. Coasts of the Eastern Atlantic and Western Pacific were hotspots of concentrations of several pollutants, and mostly affected by warming climate. These hotspots shared the same features of large populations, heavy industry and (semi-) closed sea. Estimation of coastal ocean capital, integrated management of land-ocean interaction in the coastal zone, enhancement of integrated global observation system, and coastal ecosystem-based management can play effective roles in promoting sustainable management of coastal marine ecosystems. Enhanced management from the perspective of mitigating pollution and climate change was proposed.

Element variability in lacustrine systems of Terra Nova Bay (Antarctica) and concentration evolution in surface waters

Major, minor and trace elements were determined in freshwater of lacustrine systems in Terra Nova Bay, along Victoria Land coast, Antarctica, as well as in algae and mosses. The samples were collected during some of the sampling campaigns between 2007 and 2011 (and the one of 2002) within the framework of the Italian National Program of Research in Antarctica (PNRA). Data were processed with chemometric techniques. Results showed that elements typically considered as potential anthropogenic pollutants (e.g. As, Pb, Zn, Cu and Ni) present a strong correlation with the lithogenic elements (e.g. Al, Si, Fe) in all matrices, suggesting that their origin is connected to natural phenomena. Metal concentrations in vegetation samples are in the same range as previously published data. The obtained results were compared with older literature data (since the early '90s) from the same lacustrine systems, in order to present a historical overview of element concentrations. This approach furnishes important information on surface water evolution as a function of time. A considerable variability was observed in metal concentrations but no clear trend was identified. This suggests that their concentration evolution is hardly correlated to specific natural or anthropic phenomena. No evidence of an increase of concentrations over time was apparent. Our results represent new important data about metal concentrations in lacustrine systems in Antarctica, furnishing ranges of values that can be considered as a reference. These data, therefore, could be used to detect or monitor future local and/or global anthropogenic contaminations.

3,3'-dichlorobiphenyl (non-Aroclor PCB-11) as a marker of non-legacy PCB contamination in marine species: comparison between Antarctic and Mediterranean bivalves

In this study the accumulation of the 3,3'-dichlorobiphenyl (PCB-11) in monitoring organisms from the Antarctic and Mediterranean coastal environments has been investigated. This lesser-known PCB congener, unrelated to the industrial use of commercial mixtures, continues to be generated and released into the environment mainly as an unintentional by-product of pigment manufacturing. Specimens of the filter-feeders Adamussium colbecki from Terra Nova Bay and of Mytilus galloprovincialis and Ruditapes philippinarum from the north-western Adriatic coasts were collected and analyzed for PCB-11 by Gas Chromatography coupled both to Low-Resolution and High-Resolution Mass Spectrometry (LRMS, HRMS). In order to assess the influence of PCB-11 with respect to the legacy contamination, 126 PCB congeners related to the Aroclor commercial mixtures were simultaneously analyzed. PCB-11 was detected in all the samples, regardless of the species and of the geographical area, representing on average 17.6% and 15.6% of the total PCBs (n = 127) in Antarctic and Mediterranean samples, respectively. In the Adriatic area the highest concentrations were related to the influence of industrial activities or ship traffic, while the highest value found in Antarctic specimens, namely those collected in the austral summer 1997-1998, was ascribed to a local anthropogenic source. The occurrence of PCB-11 in the other samples from Terra Nova Bay may be related to Long-Range Atmospheric Transport (LRAT), facilitated by the higher volatility of the analyte compared to the heavier PCB congeners. Nevertheless, more in-depth studies are needed in order to evaluate the relative contribution of local and distant sources.