In this study, researchers carried out the first comprehensive biological assessment of all four Macrourus species caught in South Georgia waters, using fishery and observer data collected between 2018 and 2022. By analysing distribution patterns, depth preferences, sex ratios and habitat associations, the team was able to characterise each species individually and assess their respective vulnerabilities to fishing pressure.

The results revealed striking differences between species. Three of the four showed female-biased sex ratios, which has direct implications for stock productivity and reproductive capacity. Each species also occupied a distinct depth range and geographic distribution: M. holotrachys was the most frequently caught and ranged widely between 1000 and 1750 metres; M. caml showed the greatest flexibility in habitat use; M. carinatus was concentrated in the western region; and M. whitsoni was rarer, found mostly in deeper waters beyond 1500 metres in the northeast and east.

These findings highlight a significant gap in how by-catch is currently managed. Reporting species collectively at genus level masks the fact that each faces different levels of risk, and that the health of the target fishery is not a reliable proxy for the condition of non-target species. The authors argue that species-level monitoring and accurate data collection are essential for setting meaningful by-catch thresholds and ensuring the long-term sustainability of toothfish fish fisheries across the CCAMLR area.

Source:Abreu, José, et al. “Distribution and ecology of the four Macrourus species by‐caught in the longline fishery at South Georgia, Southern Ocean.” Journal of Fish Biology (2026).

Author: Lucas Bastos

Despite their importance, scientists have only scratched the surface of understanding which microbes live in the Arctic and what they do. Why? Mostly because of methodology constrains, studies until now have relied on sequencing just small fragments of microbial DNA, making it difficult to identify many species accurately.

This’s where this study comes in. Scientists wanted to test if there were differences between sequencing the full-length 16S rRNA gene and just sequencing short regions of the gene. Also, teste the influence of databases, comparing the commonly used SILVA databased to the more recent Genome Taxonomy Database (GTDB). Researchers thought that sequencing the entire gene and using GTDB for taxonomic assignment would recover a much more complete and accurate view at Arctic microbial communities.

The results? Indeed, using the two tools combined, the researchers were able to identify many more microbial species (Figure 1). Not only did they confirm the presence of known groups, but they also discovered new lineages and better classified many species that had previously been hard to identify to such taxonomic detail.

Why is this important? As the Arctic warms faster than any other region on Earth, understanding how its ecosystems work is more urgent than ever. Microbes are incredibly sensitive to changes in temperature and nutrients and if they change, the effetc can ripple through the entire ecosystem. So, by knowing who these microbes are and how they function, scientists can better monitor/predict how the Arctic is/will respond to climate change.

This study gives us a clearer way to investigate the hidden life of the Arctic Ocean. By using full-length gene sequencing and modern classification tools, researchers identified more species, painting a more detailed picture of Arctic microbial life.

Source: Pascoal, F., Duarte, P., Assmy, P. et al. Full-length 16S rRNA gene sequencing combined with adequate database selection improves the description of Arctic marine prokaryotic communities. Ann Microbiol 74, 29 (2024). https://doi.org/10.1186/s13213-024-01767-6

Author: Lucas Bastos

But how did they do it? In this study, the scientists turned to eastern rockhopper penguins (Eudyptes chrysocome filholi), from Campbell Island (a sub-Antarctic island of New Zealand) as a biosampler. Researchers collected cephalopods’ beaks from their diet from two breeding seasons (1986–87 and 2012–13) in which they performed stable isotope analysis (SIA), forms of chemical elements that do not undergo radioactive decay. Using this method, they were able to examine the carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopic signatures, which provide insights into the habitat and trophic level of organisms. δ¹³C values help to differentiate between inshore and offshore foraging habitats, while δ¹⁵N values indicate the organism’s position in the food web.

What did they find? Using the beaks, scientists were able to pinpoint the differences in cephalopod biodiversity in the diet of penguins between the two breeding seasons. The 1986-87 diet comprised seven cephalopod species while, contrastingly, the 2012-13 diet included only three species: Moroteuthopsis ingens, Nototodarus sloanii, and Octopus campbelli. Moreover, M. ingens and O. campbelli were present in both seasons, but N. sloanii was only found in the 2012-13 season. And what does this mean? Firstly, the overall diversity seemed to decrease, however, this is likely due to the smaller sample size (Nº1986-87= 69 vs Nº 2012-13= 11). Secondly, the identification of N. sloanii may indicate a southward habitat expansion, as this species is more common in the warmer waters of New Zealand.

What about the SIA? These revealed variations in habitat and trophic niches between species. Specifically, M. ingens showed no significant differences in δ¹³C or δ¹⁵N values between years (Figure 1), while for O. campbelli δ¹³C and δ¹⁵N values were significantly lower in 2012-13 compared to 1986-87 (Figure 2), suggesting a shift in foraging location and possibly a move to lower trophic levels. N. sloanii, presented δ¹³C values in accordance with the values of other sub‑Antarctic waters taxa and lower δ¹⁵N values indicative of foraging at lower trophic levels.

What does this mean? The differences in stable isotope values between seasons could be a sign of changes in oceanographic conditions such as warming waters, taking species to new habitats and feeding differently. Additionally, the presence of N. sloanii in diets offers insights into their foraging and possible interactions with New Zealand fisheries, which can affect both the fisheries and the conservation of the eastern rockhopper penguin.

Overall, this study contributes significantly to increasing the knowledge of cephalopod ecology in the Pacific sector of the Southern Ocean. It demonstrates that different cephalopod species exhibit distinct habitat preferences and trophic roles. The findings reinforce the importance of continued monitoring of cephalopod populations, particularly in the face of environmental changes that may alter their distribution and availability to predators like rockhopper penguins.

Source: Guímaro, H. R., Thompson, D. R., Morrison, K. W., Fragão, J., Matias, R. S., & Xavier, J. C. (2025). Evidence of eastern rockhopper penguin feeding on a key commercial arrow squid species. Polar Biology, 48(1), 1-7

Author: Lucas Bastos

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

Presently, there are 112 research stations in Antarctica, with 62 located in coastal regions for ease of access. However, while these stations have greatly benefited scientific endeavours, they have also introduced environmental challenges that were previously non-existent. This article focuses on the environmental effects of the Australian research base “Casey” on the surrounding marine environment.

The original Casey station was constructed 1960’s on the Bailey Peninsula, replacing a previous Australian station. Due to poor building quality, the station was dismantled in the 1980s, and a new  Casey station was built 1 km away (Fig 1). Today, this new station comprises 18 permanent buildings that can house up to 120 people, with an average population of 25 in winter and 90 in summer.

Up until 1986, solid waste from Casey Station was disposed of in a site at Thala Valley (Fig 2), causing environmental contamination in Brown Bay by erosion and melt streams carrying contaminated material into the waters. After the Protocol on Environmental Protection to the Antarctic Treaty (Madrid Protocol), signed in 1991, Australia had to remove most waste from Antarctica, leading to improvements in waste management and environmental protection. Efforts were made to remediate the Thala Valley waste disposal site, including waste removal, construction of meltwater trenches, and the installation of a water treatment plant to prevent further contamination of the nearby waters. The concentrations of metal contaminants in the soil and seabed floor were also assessed, and a monitoring program was initiated to evaluate the effectiveness of these measures.

By analyzing sediment samples from 1997 to 2015, focusing on variations in sediment properties and contaminants, the study revealed a clear signal of anthropogenic contamination in the marine environment around Casey Station. Multiple pollutants were found in marine sediment in levels several orders of magnitude greater than control locations.

Brown Bay (adjacent to the former waste disposal site) was contaminated with pollutants at levels higher than observed anywhere else, Shannon Bay (site of wastewater outfall) and the Casey Wharf also had consistently higher concentrations of contaminants than controls, while Wilkes (adjacent to an older waste disposal site) had lower levels and most contaminants were close to background values. Notably, Brown Bay Outer displayed an increase in contaminant concentrations from pre-2000 to 2014, suggesting the movement of sediment-bound contaminants from Inner to Outer sites, possibly due to resuspension and lateral transport. These patrons of contamination coincide with the distance to the current location of the station, the closer the site higher the contamination.

Contamination levels of sites around Casey were found to be much higher than those at other Australian stations but similar to those at impacted areas near the USA’s McMurdo Station. Brown Bay levels of contamination are also similar to some heavily modified estuaries worldwide such as the Sydney Harbour and Rio de Janeiro and may have significant effects on the health of benthic fish species, as observed in other stations. Nevertheless, the article highlights that the spatial extent of contamination around Antarctic stations is likely limited to a few kilometres from the station due to the calm nature of Antarctic coastal sub-marine environments.

In summary, the article underscores the environmental impacts associated with research bases like Casey in Antarctica. While these bases are essential for scientific research, they must be managed carefully to mitigate their ecological effects on this sensitive and pristine environment.

Author: Lucas Bastos

Source: Stark JS, Johnstone GJ, King C, Raymond T, Rutter A, Stark SC, et al. (2023) Contamination of the marine environment by Antarctic research stations: Monitoring marine pollution at Casey station from 1997 to 2015. PLoS ONE 18(8): e0288485. DOI: 10.1371/JOURNAL.PONE.0288485

To study the interactions between the wandering albatross and Southern Ocean fisheries, radar GPS-loggers were attached to the seabird individuals, along with information regarding the position and movements of fishing vessels. This study considered the different life stages and sex of the wandering albatross, which are usually under-researched or not considered in many studies.

The results showed that different types of gear used in fisheries make the visiting of the wandering albatross differ. The fisheries that use set (demersal) longliners had a higher likelihood of being visited by this seabird than other gear types (mainly trawlers, squid jiggers and drifting longliners).

When analysing the bycatch rate of different life stages of the wandering albatross, the results showed an increase in the visits of fishing vessels by the wandering albatross during the incubation period (Fig. 1). However, it’s important to note that if discards are not occurring this seabird won’t visit the vessel, in the case that prey is available in the surroundings.

In order to reduce mortality bycatch associated with fisheries of the wandering albatross and other vulnerable seabird species, it’s important to engage with the managers and operators of the main fisheries that come in contact with these species and implement best practices regarding seabird-bycatch mitigation, seabird bycatch rates and monitoring of compliance.

Source: Carneiro, A. P. B., Clark, B. L., Pearmain, E. J., Clavelle, T., Wood, A. G., & Phillips, R. A. (2022). Fine-scale associations between wandering albatrosses and fisheries in the southwest Atlantic Ocean. Biological Conservation, 276. DOI:  https://doi.org/10.1016/j.biocon.2022.109796

Author: Mariana Quitério

The Scientific Committee on Antarctic Research (SCAR) has a large information base that allows policymakers access to relevant and reliable scientific knowledge. The environmental protection protocol of the Antarctic treaty works to assess the environmental impact of certain activities, such as the conservation of fauna and flora, waste disposal and management, and the area’s protection and management.

There are advantages in science contributing to policymaking, as it allows:

• The understanding and response to the environmental consequences of climate change in the Antarctic region;
• To address risks to biodiversity associated with the introduction to Antarctica of non-native species, including the transfer of native species between bioregions within Antarctica;
• Appropriately management of the environmental impacts of tourism and non-governmental activities; and
• To improve the effectiveness of protected area management, and further developing the Antarctic protected area system.

The inclusion of scientists from various countries and/or multinational support for presented research evidence can facilitate the construction of the Antarctic Treaty System (ATS). The greater involvement of early-career scientists, including through the Association of Early-Career Polar Scientists (APECS), may provide an additional opportunity to enhance the interface between science and policy.

The authors of this article also explain how to improve the policymaking process. For example, by raising awareness among the scientific community about opportunities to inform environmental policymaking within the ATS. Also, a clearer communication by the ATCM and CEP in relation to specific knowledge gaps that must be filled to contribute to advancing Antarctic environmental protection. SCAR could further assist in strengthening the communication among its members on areas of research by the ATCM and the CEP. It is also important to continue to inform the scientific community through meetings on the routes where relevant policies are formed from good scientific communication to policymakers. This cooperation between scientists and politicians provides an efficient implementation of measures that strengthen the governmental structure of Antarctica, a continent that equals the space of Europe. There is still a need for better science and policy communication, combined with better science funding planning, relevant to policies to protect the Antarctic environment.

Source: Hughes, K. A., Constable, A., Frenot, Y., López-Martínez, J., McIvor, E., Njåstad, B., Terauds, A., Ligget, D., Roldan, G., Wilmotte, A. &  Xavier, J. C. (2018). Antarctic environmental protection: Strengthening the links between science and governance. Environmental Science & Policy, 83, 86-95. https://doi.org/10.1016/j.envsci.2018.02.006

Author: Raquel Coimbra

Defining these Areas is particularly complex, often including international waters, or waters in exclusive economic zones of different countries, or even important areas of marine resources. However, it is crucial that these areas encompass ecologically highly important zones for as many species as possible.

Thus, this study, conducted in the Southern Ocean that surrounds the entire Antarctic continent, sought to identify the most important areas using 17 species of birds and marine mammals that inhabit and/or use this region, from penguins, albatrosses, seals, whales, etc.

This identification was made using data obtained by GPS (placed in the different species), which gives us the location and movements of the animals, in response to more than 15 environmental variables (e.g.: ice concentration, depth, salinity etc.) Finally, with the use of computational models, it was possible to identify ecologically important areas for a large number of species, thus representing crucial areas for their success (Figure 1).

Finally, this knowledge considerably increases our understanding of this region and helps to establish which zones and areas should potentially be protected in the future and included as Marine Protected Areas due to their important ecological function.

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Source:

Reisinger, R. R., Brooks, C. M., Raymond, B., Freer, J. J., Cotté, C., Xavier, J. C.,.. & Hindell, M. (2022). Predator-derived bioregions in the Southern Ocean: Characteristics, drivers and representation in marine protected areas. Biological Conservation, 272, 109630.

Hindell, M.A., Reisinger, R.R., Ropert-Coudert, Y. et al. Tracking of marine predators to protect Southern Ocean ecosystems. Nature 580, 87–92 (2020). https://doi.org/10.1038/s41586-020-2126-y

Author: José Abreu

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

Those images, which range from 30 to 60 cm in resolution, made it possible to distinguish these seabirds during their breeding season in sea-ice along the coast of Antarctica. Their detection is because these seabirds, usually in groups of hundreds or even thousands of individuals, leave a very representative and big mark of guano (i.e., bird excrements), which can be identified in satellite images by the contrast between the brown color of guano and the white color of the sea-ice. This allowed counting the number of emperor penguin colonies around Antarctica for the first time. Currently, it is known that there are 66 colonies.

But, as perfection is difficult to achieve, all technologies end up having their limitations. To date, to represent the total number of individuals in a given colony, only one satellite image is used per year. But can this really be accomplished with just one image per year? Does this image convey the true dynamics of that colony in one year? These questions that led north-American researchers and international colleagues to study the limitations that this technology may have for counting emperor penguins.

In this study, the researchers evaluated two types of variables that can influence the penguin counts in a given image. These variables related to the satellite itself (e.g., solar azimuth), which can cast shadows on the image preventing the correct counting of birds, and environmental variables (e.g., wind and temperature), which can influence whether the dispersion of penguins (more disperse penguins are easier to count).

Three of the most representative colonies in terms of numbers were used as study sites: Atka Bay and Stancomb-Wills (colonies in the Weddell Sea sector) and Coulman Island (a colony in the Ross Sea sector).

The authors concluded that using only one image per year to obtain conclusions about the numbers of emperor penguins in each colony may not be the best way, since the influence of the variables studied led to very different numbers of individuals throughout the months. In future research, these variables should be used as they improve the count of emperor penguins to obtain numbers closer to the reality.

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Source: Labrousse, S., Iles, D., Viollat, L., Fretwell, P., Trathan, P. N., Zitterbart, D. P., Jenouvrier, S. & LaRue, M. (2022). Quantifying the causes and consequences of variation in satellite‐derived population indices: a case study of emperor penguins. Remote Sensing in Ecology and Conservation, 8(2), 151-165. https://doi.org/10.1002/rse2.233

Author: Hugo Guímaro