In this study, the researchers carried out a comprehensive review of trace elements in soils from Antarctica’s ice-free areas, examining concentrations in pristine zones and in areas influenced by human activity, with special emphasis on the impact of permafrost thaw on their mobilization. Antarctica was divided into six regions with similar climatic and environmental characteristics, allowing results to be compared, natural and anthropogenic sources of contaminants to be distinguished, and vulnerable areas requiring future monitoring to be identified.

The results showed that the active layer of permafrost controls the accumulation and mobility of trace elements in Antarctic soils and that permafrost thaw associated with climate change can remobilize previously retained contaminants, increasing their environmental availability.

Furthermore, concentrations of elements such as Hg, Pb, Cd, Cu, Cr, and Ni arise from both natural and anthropogenic sources. In the South Shetland Islands, particularly on King George Island, higher values are recorded near scientific stations, waste sites, fuel spills, and other human infrastructures, whereas on Deception Island, volcanic activity leads to naturally elevated concentrations of Hg and As, with permafrost potentially acting as a temporary reservoir for these elements (Fig. 1). Scientists also noted that glacier retreat, increasing active-layer thickness, and permafrost degradation are altering hydrological dynamics and contaminant transport.

The combined effects of human pressure and climate change pose a growing risk to terrestrial and coastal ecosystems, underscoring the need for continuous monitoring.

Source: Zilhão, H., Cesário, R., Vieira, G. & Canário, J. (2025). Trace elements in soils of the Antarctic ice-free areas: Insights on natural geochemical values, anthropogenic impact and possible remobilisation upon permafrost thaw. Earth-Science Reviews, 268.

Author: Diana Vaz

In this study, researchers analysed two deep-sea fish species from South Georgia: Antimora rostrata (blue antimora), a more pelagic species, and Macrourus holotrachys (bigeye grenadier), a demersal species. In 2020, individuals were collected and four tissues (muscle, brain, liver and gills) were analysed, along with stable isotopes, to determine the habitat and trophic position of each species.

The results showed that:

• Muscle was the tissue with the highest mercury concentrations in both species.
• A. rostrata consistently showed lower concentrations than M. holotrachys.
• Only in M. holotrachys did Hg concentrations increase with body length and weight, suggesting bioaccumulation throughout life
• Differences also reflected habitat use, since the demersal species (M. holotrachys) is more closely associated with benthic food webs, which are generally richer in Hg.
• A. rostrata occupies a lower trophic level than M. holotrachys.

Unexpectedly, the brain showed high Hg concentrations, raising questions about potential neurotoxic effects in these fishes and their predators.

These results reveal that different feeding strategies and habitats shape contaminant accumulation in deep-sea species, with implications for ecosystem health and for top predators that depend on them.

Source: Vaz, D. B., Queirós, J. P., Xavier, J. C., Bustamante, P., Abreu, J., Pereira, E., Hollyman, P. R., Coelho, J. P. & Seco, J. (2025). Mercury Concentrations, Habitat and Trophic Position of Antimora Rostrata and Macrourus Holotrachys from South Georgia (Southern Ocean). Marine Pollution Bulletin. DOI:10.2139/ssrn.5360416

Author: Diana

Because squids are almost impossible to study alive, scientists have to rely on their beaks, hard structures that resist digestion and accumulate in the stomachs of predators to analyse their chemical signatures. In this study, researchers analysed squid beaks collected from the 1970s to the present day to measure mercury concentrations.

The results were remarkable, despite high mercury levels in the first two decades, concentration have been steadily decreasing over the past three decades. This trend suggests that global efforts to reduce mercury emissions, such as the International Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter (1972)and improvements in industrial practices, are having measurable positive effects, even in remote ecosystems like the Southern Ocean (Figure 1).

Cephalopods like M. longimana can be valuable bioindicators as they occupy a central position in marine food webs, linking smaller prey such as crustaceans and fish to large predators like seals and whales. Moreover, their short lifespan and rapid make them excellent “record keepers” of environmental conditions giving researchers a unique window into pollutant trends.

By turning squid beaks into environmental archives, scientists have provided evidence that pollution can decline when collective action is taken. These results bring hope, but also serve as a reminder of the need to sustain global commitments to pollution reduction to safeguard ecosystems.

Source: Sara Lopes-Santos, José C. Xavier, José Abreu, José Seco, João P. Coelho, Eduarda Pereira, Richard A. Phillips, José P. Queirós, Decreasing mercury concentrations in beaks of the giant warty squid Moroteuthopsis longimana in the Scotia Sea (Southern Ocean) since the 1970s, Marine Pollution Bulletin, Volume 221, 2025, 118578, ISSN 0025-326X

Author: Lucas

One such squid species, Moroteuhopsis longimana, inhabits the deep waters of the Southern Ocean and can reach more than 2 meters in total length. It bioaccumulates Hg throughout its life and is an important prey item for several top predators such as seabirds, marine mammals and fish, so understanding its role in the transfer of Hg in the food web is crucial. However, there is still a lack of knowledge about the relationship between Hg concentrations in M. longimana beaks and muscle (the main tissue consumed by the predators), which this study aims to analyse.

To do that, 21 buccal masses of M. longimana collected from the stomach of the Antarctic toothfish (Dissostichus mawson). For total Hg analysis, the upper and lower beaks were sectioned into the wing (W) and hood tip (H), and the remainder of the lower (L) and upper (U) beaks (Figure 1). A portion of the buccal mass muscle (M) was also collected for analysis.

Results showed that Hg concentrations in the muscle are ~100 times higher than in the whole beaks (U and L) and ~50 times higher than in the W and H sections (Figure 2). Inter-tissue variability in Hg concentrations confirms that the concentration of Hg in the beak does not reflect directly those in the muscle.

However, a positive relationship was found between Hg concentrations in the wing (W) and muscle (M), translated by the following equation:

Hg_músculo = 34.88 Hg_asa + 0.12

This equation suggests that mercury concentration in the wing can be used as a proxy for Hg concentration in the muscle of M. longimana. However, it should only be used for adult individuals, as this study only used fully chitinized adult beaks.

Future studies can now use this equation to estimate the Hg concentration in the muscle of other M. longimana, through the analysis of the Hg concentration in the beak wing, providing a means of assessing the levels, transport and fate of Hg in within Southern Ocean ecosystem.

Source: Lopes-Santos S, Xavier JC, Seco J, Coelho JP, Hollyman PR, Pereira E, Phillips RA, Queirós JP (2025) Squid beaks as a proxy for mercury concentrations in muscle of the giant warty squid Moroteuthopsis longimana. Marine Environmental Research 204:106841.

Author: Sara Santos

The study measured stable isotope signatures and Hg concentrations in different species, including chinstrap penguins, skuas, gulls, southern giant petrels, and southern elephant seals. Significant differences in δ13C values among species were observed, with considerable overlap between seabird species and seals. Differences in δ15N values reflected variations in diet and trophic position. The lowest Hg concentrations were found in krill (0.007 ± 0.008 μg∙g–1) and the highest in southern giant petrels (12.090 ± 14.177 μg∙g–1).

Results showed a positive relationship between Hg concentrations and trophic levels, with Hg biomagnifying nearly twice at each trophic level. The study suggests that trophic interactions are the major pathways for Hg biomagnification in Southern Ocean ecosystems. The research also highlights that Hg concentrations may increase in marine organisms due to global warming, which enhances Hg methylation and its availability in low-oxygen waters. Long-lived, high trophic level predators, such as some seabirds and seals, are particularly vulnerable to the effects of Hg.

The study concludes that Hg biomagnification in the food webs of the Antarctic Peninsula results in high Hg burdens in top predators. As global temperatures rise, Hg concentrations are expected to increase, potentially causing significant negative effects on Antarctic organisms. The article emphasises the need for further studies to fully understand how taxonomic, geographic, and ecological differences influence Hg dynamics in the marine ecosystems of the Antarctic Peninsula.

Source: Matias, R. S., Guímaro, H. R., Bustamante, P., Seco, J., Chipev, N., Fragão, J., … & Xavier, J. C. (2022). Mercury biomagnification in an Antarctic food web of the Antarctic Peninsula. Environmental Pollution, 304, 119199.

DOI: 10.1016/j.envpol.2022.119199

Author: Laura Lopes

The impact of shipping in the Arctic is extensive, and three main areas stand out: on water bodies, atmospheric emissions, and animal survival.

Impacts on water bodies include pollution from anti-fouling paints, which release copper and microplastics that affect the growth and survival of marine life, inhibit reproduction, and cause deformities. In addition, oil spills pollute coastlines and beaches, affecting animal health, reproductive cycles and mobility, leading to the death of many species. Introducing non-native species (NNS) leads to loss of biodiversity and local extinctions. Sewage discharges also lead to pollution, depletion of dissolved oxygen, red tides and toxicological effects on the Arctic ecosystem.

Impacts on atmospheric emissions encompass air pollution and changes in atmospheric composition due to ship emissions, which disrupt radiative forcing (RF), accelerate Arctic warming, cause acid rain, and eutrophication of seawater.

Impacts on animal survival involve noise pollution, which disrupts Arctic animals’ communication, altering behavioural patterns and potentially causing temporary or permanent hearing loss. Light pollution disrupts the orientation of marine animals and causes collisions, especially between birds.

To mitigate these negative impacts, it is essential to adopt technical and operational solutions for ships, as well as to formulate stricter standards and rules for Arctic shipping activities.

Reference: Xinli Qi, Zhenfu Li, Changping Zhao, Qiqi Zhang, Yutao Zhou, Environmental impacts of Arctic shipping activities: A review, Ocean & Coastal Management, Volume 247, 2024, 106936, ISSN 0964-5691

https://doi.org/10.1016/j.ocecoaman.2023.106936

Author: Rita Quelha

Seabirds, as top predators, reflect the Hg contamination that is present in their marine food web, through biomagnification processes. Their main form of Hg excretion is through moulting. Within seabirds, the Adelie penguin (Pygoscelis adeliae) (Figure 1) has a set of ideal characteristics to be used as a bioindicator for Hg concentrations in Antarctic food webs, since it has a circumpolar distribution and is the most common and abundant penguin species on the Antarctic continent.

For the circumpolar assessment of Hg concentrations, feather samples were collected from 538 individuals (490 adults of reproductive age and 48 pre-fledging chicks) between 2005 and 2021 in 24 colonies around the continent. Total mercury (T-Hg) concentrations were evaluated for each sample. Values of the isotopes δ¹³C and δ¹⁵N were also determined on the feathers and used as proxies for the feeding habitat and trophic position of the penguins, respectively.

At the circumpolar level, Hg contamination proved to be relatively homogeneous between the different regions assessed. However, a Hg hotspot was observed in the Ross Sea (Figure 2), associated with a higher trophic position of Adélie penguins, likely due to a higher proportion of fish in their diets.

It is essential to continue monitoring Hg concentrations to assess the effectiveness of the Minamata Convention on Mercury. Large-scale assessments are extremely important to monitor the contamination status of Antarctic food webs over time, and also to assess global trends, taking into account the climate change context.

Author: Sara Santos

Source: Cusset, F., Bustamante, P., Carravieri, A. et al. Circumpolar assessment of mercury contamination: the Adélie penguin as a bioindicator of Antarctic marine ecosystems. Ecotoxicology 32, 1024–1049 (2023). https://doi.org/10.1007/s10646-023-02709-9

DOI: https://doi.org/10.1007/s10646-023-02709-9

Between 2017 and 2019, samples from the adipose tissue of ringed seals captured by indigenous hunters from western Canada were examined. The technique used for the analysis has a capacity to detect microplastic particles as small as 10 microns. Surprisingly, the results indicated that none of the samples contained detectable microplastics. This differs from previous studies that found high levels of microplastics in the adipose tissue of other seal species, such as ribbon seals.

Fibers are usually the most common type of microplastics found in marine mammals, followed by fragments and films. Even though the researchers have found small plastic based fibers in the samples, it is believed that their origin is based on contamination during sample handling in the laboratory. Cohen’s D, or standardized mean difference, is a common way to test whether an effect size is significant, statistically speaking, which in this case related to the ingestion of microplastic particles. In this study, with a sample size of content from 10 seal individuals, the observed effect was 0.37. For that value to be sifnificant, the sample would have to be composed of 91 individuals, being that with the 10 individuals examined, the effect would only be significant with a Cohen’s D value of at least 1.16 (blue and red lines, respectively, Fig.1).

According to the researchers, the absence of microplastics in ringed seals in this study may be related to a small ingestion of plastic particles, compared with other marine fauna. Their main food supply is composed by fish, which presents a far less probability of microplastic ingestion, contrary to a diet dominated by benthic invertebrates. However, it is also possible that the technique used for analysis may not have been the most sensible to detect plastic particles with smaller dimensions, or that the study region in Canada is not exposed to the same levels of microplastics as other areas.

Although this study provides us with good news on this microplastic free ringed seal population in western Canada, it is still important to remember that other studies of the same kind have found high levels of microplastics in other populations around the world. Therefore, it is crucial to continue researching the presence and effects of microplastics in marine ecosystems in order to better understand their impacts and take measures to protect marine life and human health.

Overall, this study highlights the need for continued research on microplastics and their effects on marine organisms. It also emphasizes the importance of taking action to reduce the amount of plastic pollution in the ocean, through measures such as reducing plastic use and improving waste management systems. By working together to address this global issue, we can help protect marine ecosystems and the animals that rely on them for survival! 

Source: Jardine, A.M., Provencher, J.F., Insley, S.J., Tauzer, L., Halliday, W.D., Bourdages, M.P.T., Houde, M., Muir, D., Vermaire, J.C. (2023). No accumulation of microplastics detected in western Canadian ringed seals (Pusa hispida). Mar Pollut Bull. 2023 Mar;188:114692

DOI: 10.1016/j.marpolbul.2023.114692

Author: Laura Lopes

In this context, numerous studies have documented plastic pollution in the recent decades, to better understand the scale of this problem.

The most common thinking in society, when talking about plastic, is as large objects such as bottles, bags, among others, yet, the problem of plastics is more serious due to its fragmentation, which ends up producing thousands of small pieces, many almost or even invisible to the naked eye. There are different categories, but these can be from nano-plastics (< 1 nanometre) or macro-plastics (> 10 millimetres).

This study thus reveals an overview of the current state of plastics in Antarctica, the possible sources, impacts and measures that are being taken. Nano-plastics usually are originated in commercial products and their consequent fragmentation, in pharmaceutical activity, detergents, cosmetics, etc. Although remote, a considerable part of the occurrence in Antarctica is brought by oceanic and atmospheric currents, which end up aggregating marine “garbage” more strongly in some regions than others. Currently, the Antarctic Peninsula region, in the Atlantic sector of the Southern Ocean, is the most affected region in Antarctica, and the one that suffers the most human pressure. In addition to the origins mentioned above, fishing and tourism are also a major source of plastic pollution in the Southern Ocean.

In addition to their presence, in the oceans, ice shelves, continents and Antarctic islands, the ingestion of plastics has already across the different species have also been documented, from birds (i.e.: albatrosses, penguins), fish (i.e.: icefish, cod from Patagonia), benthos (sea urchin), etc.

Among the impacts, plastic can serve as a carrier of bacteria and pathogens, which do not normally occur in Antarctica, and thus have serious consequences for the local fauna and flora. Ingestion by different species can also bring health risks to the animals themselves since many of these plastics have toxic chemicals in their composition. On the other hand, the ingestion of large pieces, such as ropes, fishing nets, lines, has already caused the death of countless individuals, or strangulation situations that cause serious wounds and inflammation.

Currently, with the recognition of this problem, many of the most active players in this region have been creating conditions and measures aimed at reducing the introduction of plastic in this crucial area of planet Earth. As an example, the Scientific Committee on Antarctica Research (SCAR) created in 2018 a working group exclusively dedicated to understanding and evaluating the different sources, distribution and occurrence of plastic. The Antarctic Treaty itself is also integrating this new challenge, and its Annex IV already mentions the total ban on any plastic disposal in Antarctic waters. In turn, the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) has imposed the reduction of various plastic objects to the minimum possible in fishing activities. Finally, tourism has increasingly carried out educational activities in this area, cleaning coastal areas, and supporting research and conservation in this regard.

Ahead, there is still the challenge of understanding as best as possible the real effects that plastic will have in this region, and how we can effectively mitigate it. However, stakeholders, from governments, companies, tourism, science, are moving in the direction to fight this problem together.

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Source: Caruso, G., Bergami, E., Singh, N., & Corsi, I. (2022). Plastic occurrence, sources, and impacts in Antarctic environment and biota. Water Biology and Security, 100034. https://doi.org/10.1016/j.watbs.2022.100034

Authors: Diana Rodrigues and José Abreu

In a recent study, young Portuguese scientists used mass spectrophotometry techniques in order to carry out the first screening for the presence of emerging contaminants (such as POPs and PPCPs) in the phytoplankton community of a remote island in Antarctica, which is visited by tourist and scientists, thus providing important information about the human footprint left in these remote ecosystems.

More than 70 persistent pollutants of human origin (including POPs and PPCPs, among others) were detected. Overall, the variety of compounds detected, as well as their uses, may be linked to both terrestrial and marine activities, thus highlighting the anthropogenic contribution to the Antarctic ecosystem. The detection of these compounds at the base of the Antarctic food chain, which can be potentially toxic depending on their concentration, could have very serious implications for the entire trophic structure of the ecosystem, putting the various organisms at risk.

That said, this study emphasizes the knowledge gap that exists regarding the potentially toxic effects that these pollutants can have on the various organisms in the Antarctic food chain. It also emphasizes the need to review the guidelines imposed by the Antarctic Treaty and by the Environmental Protection Protocol to the Antarctic Treaty, so that there is a control and/or avoidance of the proliferation of these and other PPCPs in remote environments as unique as is the case of Antarctica.

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Source:Duarte, B., Gameiro, C., Matos, A. R., Figueiredo, A., Silva, M. S., Cordeiro, C., Caçador, I., Reis-Santos, P., Fonseca, V., & Cabrita, M. T. (2021). First screening of biocides, persistent organic pollutants, pharmaceutical and personal care products in Antarctic phytoplankton from Deception Island by FT-ICR-MS. Chemosphere, 274, 129860. https://doi.org/10.1016/j.chemosphere.2021.129860

Author: Joana Fragão