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

As we mentioned in November, a team of researchers developed a groundbreaking tool called HLWATER V1.0, capable of automatically identifying these lakes. The study centred on the Nunavik region in Subarctic Canada, a stunning landscape where tundra meets boreal forest, forming an extensive network of water bodies, from glacial lakes to peatland ponds. 

But what comes next? What new discoveries have they made? Identifying these lakes is insufficient. It is essential to study them and understand their characteristics and spatial patterns, and that’s precisely what the team concentrated on in this new scientific paper. This time, the team examined three key parameters of the lakes: limnicity (size), limnodensity (quantity), and limnodiversity (optical diversity or colours, an important indicator of their chemical composition). 

And what did they find? Of the more than 335,000 lakes in this region, 90% are smaller than 0.01 km², meaning they are tiny. The larger lakes are found in glacial depressions on rocky outcrops. The highest limnodiversity occurs on valley slopes, where silt-clay deposits dominate and where permafrost degradation is most intense. Additionally, this is where we see the greatest limnodiversity, with black and brown lakes, rich in organic matter, and light brown or even white lakes, where mineral sediments predominate. 

Although these landscapes cover only 2 to 7% of the region, they contain more than 1/3 of all water bodies. And why is this important? Unfortunately, these lakes are not just beautiful; they release greenhouse gases, influence the climate, and impact the entire planet. 

Now that we can map and analyze these lakes with greater precision, can we predict how they will change in the future? Science continues to investigate!

Source: Freitas, P., Vieira, G., Martins, D., Canário, J., Pina, P., Heim, B., … Vincent, W. F. (2024). Diversity of lakes and ponds in the forest-tundra ecozone: from limnicity to limnodiversity. GIScience & Remote Sensing, 61(1).

Author: Diana Martins

But here’s the breakthrough: researchers have developed HLWATER V1.0, an innovative image analysis tool powered by the advanced AI model Mask R-CNN. Trained on high-resolution PlanetScope satellite images, this AI can automatically identify and map even the smallest ponds, down to 166 m²! The research was conducted in Nunavik, Subarctic Canada, a stunning and complex landscape where tundra meets boreal forest, dotted with everything from glacial lakes to ponds in peatland areas.

And the results? Game-changing! The AI model successfully mapped diverse types of water bodies, even in the most challenging environments where traditional methods fail. This new approach opens up the possibility of monitoring vast Arctic and Subarctic regions more accurately and comprehensively. By tracking changes in these small water bodies, scientists can better understand the impact of climate change and how greenhouse gases are released from thawing permafrost.

This study showcases the incredible potential of artificial intelligence and high-resolution satellite imagery to revolutionize environmental monitoring. It’s a major step forward in the global mission to understand and adapt to climate change, and protect these vital, yet often overlooked, ecosystems!

Source: Freitas, P., Vieira, G., Canário, J., Vincent, W., Pina, P., & Mora, C. (2024). A trained Mask R-CNN model over PlanetScope imagery for very-high resolution surface water mapping in boreal forest-tundra. Remote Sensing of Environment. 304. 10.1016/j.rse.2024.114047.  

Author: Diana Martins

The study found significant changes in the habitat of four out of the five squid species, as indicated by shifts in δ¹³C values. This suggests that these species have changed their geographical distributions over time, likely in response to environmental changes. Taonius sp. B, Gonatus antarcticus, Galiteuthis glacialis, and Histioteuthis atlantica all showed changes in habitat, moving towards more northerly regions over the decades. Moroteuthopsis longimana (Figure 1) was the only species that maintained consistent habitat use, indicating a potentially greater tolerance to environmental changes.

Despite changes in habitat, the trophic levels of all five squid species, as concluded from δ¹⁵N values, remained relatively stable over the study period. This suggests that their roles within the food web have not shifted significantly, maintaining their importance as prey for top predators.

Of the five species, only Taonius sp. B showed a significant correlation between its isotope ratios and the environmental indices (SOI and SAM), indicating that these climatic factors directly influenced its trophic level and habitat.

In conclusion, the study suggests that while Southern Ocean squid have altered their habitat in response to changing environmental conditions, their trophic roles have remained stable. This adaptability could ensure their continued importance in the Southern Ocean ecosystem, even as climate change progresses. The findings highlight the potential resilience of these species to environmental variability and their critical role in the marine food web. This research provides valuable insights into the ecological responses of key nekton species in the Southern Ocean, which could be crucial for predicting future changes in the ecosystem under ongoing climate change.

Source: Abreu J, Phillips RA, Ceia FR, Ireland L, Paiva VH, Xavier JC (2020) Long-term changes in habitat and trophic level of Southern Ocean squid in relation to environmental conditions. Sci Rep

DOI: 10.1038/s41598-020-72103-6

Author: Sara Santos

These changes can have important effects on ecosystems, especially when the spatial variability of the cover is high, influencing the biogeochemical conditions (examples: moisture, temperature, nutrients) of the underlying soil, as well as vegetation and light. It also controls species distribution, growth phase duration and phenology.

The study highlighted this month was conducted on Signy Island, Antarctica, where snow thickness and area distribution were monitored using a time-lapse camera on a 15 x 20 meter grid over an 8-year period (2009-2017).

The results confirmed the high spatial and temporal variability of the snow cover. During the study period, the annual mean snow depth ranged from 5.6 cm (2017) to 11.1 cm (2012), while the maximum daily mean snow depth across the grid ranged from 17.1 cm (2017) to 50.1 cm (2015). Although no temporal trend was visible, a strong correlation with the mean annual air temperature was observed, suggesting that a possible future warming could decrease the snow depth in the area.

In addition, it was also possible to verify the presence of vegetation as a bioindicator of snow thickness, in line with previous studies.

For example, vegetation dominated by Andreaea spp. is associated with thinner snow cover, and this cushion moss community occurs in exposed, dry to wet habitats with intermittent water supply after the end of snow melt in spring. In the thicker snow cover, a moss community dominated by Sanionia uncinata is found, which requires higher water availability, occurring in mesic and hydric habitats.

It was observed that the Usnea dominated lichen vegetation is limited to areas with low snow cover, so it can be confirmed that this plant formation can be indicative of areas with low snow accumulation. In addition, its presence is associated with earlier snow melting, (Fig. 2 – C), since its structure, color and thermal properties favor early melting and delay snow accumulation. 

The data demonstrates the importance of microtopography and wind direction, as well as the type of ground cover (vegetation), on snow cover patterns, since these factors influence the processes of snow accumulation, redistribution and ablation. It also highlights the importance of spatial monitoring of snow accumulation at a small physical scale in order to predict the future effects of climate change on sensitive terrestrial ecosystems in Antarctica.

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Source: Tarca, G., Guglielmin, M., Convey, P., Worland, M. R. & Cannone, N. Small-scale spatial–temporal variability in snow cover and relationships with vegetation and climate in maritime Antarctica. Catena vol. 208 105739 (2022). DOI: 10.1016/j.catena.2021.10573

Author: Márcia Dias

However, due to the decrease in the extent of this ice, they have difficulties foraging for their prey. Consequently, the decrease access to prey can cause a cycle of negative effects, from reduction in the body condition, to a decrease in the number of cubs and, in some regions, a population decline.

Despite the existence of a few studies that address the effect that climate induces on the extent of sea ice and consequently on polar bear populations, it is equally essential to understand the impacts that climate change can have on the individual behaviour of this species (e.g., increased demand for land resources; increase in human-bear conflicts). Thus, drones have become an important tool for wildlife conservation research since they are recognized as an alternative to traditional methods for data collection. Being an accessible and non-invasive tool, it can be a good alternative to collect data without disturbing wildlife.

In this study, the authors highlight the benefits of using drones to study the behaviour of polar bears. They used drones to study the polar bear foraging behaviour on East Bay Island, Nunavut, Canada (64°01’47.00” N, 81 °47’16.7” W) over three field seasons (2016 – 2018).

Regarding the benefits that drone’s utilization can bring to study the polar bear behaviour, authors had divided them in the following fields:

• Human and bear safety
• Data collection and quality
• Data storage and review
• Collaboration opportunities with local communities

Besides those benefits, the authors also identify potential drone applications for polar bear behaviour research:

• Foraging behaviour
• Interspecific interactions
• Human-bear interaction
• Human safety and conflict mitigation
• Den site location

Studying individual-level responses of polar bears to the effects of climate changes will allow to collect information about their individual behaviour and consequently may help to characterize population trends. The use of drones can be a very useful mechanism to understand the polar bear’s behaviour at an individual level on small spatial scales, where traditional mechanisms and researchers themselves are often unable to reach and monitor. In this way, the drone can be, presently and in the future, a crucial tool in helping the conservation of this species, providing data previously unknown to scientists.

Authores: Joana Fragão e José Abreu

Source: Jagielski, P. M., Barnas, A. F., Grant Gilchrist, H., Richardson, E. S., Love, O. P., & Semeniuk, C. A. (2022). The utility of drones for studying polar bear behaviour in the Canadian Arctic: opportunities and recommendations. Drone Systems and Applications, 10(1), 97-110.

This Ocean, where numerous species live, most of which are endemic to this region, due to the dynamics and interaction of water currents in this part of the planet, and which end up being much more sensitive to these events. One of the most important currents for prey and predators in the Southern Ocean is the Polar Front. However, with the progressive increase in ocean temperature, it is expected that the Polar Front will contract towards the south, towards the Antarctic continent. Thus, these spatial changes in the Polar Front may cause difficulties for predators that forage for their prey in that area.

Interestingly, these climate changes in the ocean, contrary to what we usually think, can have different consequences in the same species.

Such case is the King Penguins. Among the various colonies that exist scattered around the South Pole, two of them are found on the Kerguelen Islands and the Crozet Islands, which are 1400km away. However, in recent years it has taken different directions, with the Kerguelen penguin population growing and in the Crozet Islands significantly decreasing.

So, to understand the influence of these events with high temperatures in the ocean on these populations and to find out if they would be complicit in this outcome, a team analysed 25 years of data. They analysed where the penguins foraged for food and how long it took, the number and success of the chicks, including their weight.

The results are interesting, and completely different. Overall, they confirmed that the reproductive success of king penguins varies dramatically from year to year, mainly due to climatic differences. However, distinctly on the two islands. In Kerguelen, the position of the front is much closer to the island, and changes in its position in the ocean do not significantly affect the capture of prey for chicks by penguin couples. The researchers even suggest that it is possible that these higher temperatures are having a positive effect on the abundance and growth of prey and consequently greater reproductive success in the penguin population. At the same time, during the winter, these warmer conditions will increase the probability of survival of the hatchlings. On the Crozet Islands, the king penguin population has been declining. On this island position on the Polar Front, it has varied between 217 and 642km to the island, 10x more when compared to Kerguelen. Due to the characteristics of each region, the position of the Polar Front is much more mobile in Crozet, being even more accentuated during these high ocean temperature events. Thus, king penguins are forced to travel greater distances to find prey, when compared to Kerguelen. Consequently, this increase in expenditure of time and energy, and sometimes failure to capture prey, is reflected in a greater probability of death for the offspring.

In the future, with the continuation of these changes and climatic events, the Polar Front will also continue to move towards the south. As we can see, the same process will have completely different results in king penguins from two subantarctic islands. Hoping that the population on Kerguelen will continue to grow and will eventually replace the Crozet colony which continues to see numbers dwindle.

Therefore, it is always important to evaluate and consider not only large-scale processes but also local and regional characteristics to obtain more reliable results from which we can act correctly.

Source: Brisson‐Curadeau, É., Elliott, K., & Bost, C. A. (2022). Contrasting bottom‐up effects of warming ocean on two king penguin populations. Global Change Biology https://doi.org/10.1111/gcb.16519

Author: José Abreu

This species, like many other whales, moves within the ocean, between their breeding and feeding grounds. Consequently, humpback whales perform large annual migrations, feeding in the Antarctic polar waters during the austral summer.

Before commercial exploitation, South Georgia and the South Sandwich Islands in the Atlantic part of the Southern Ocean were one of the most important habitats for the humpback whale. This area is rich in Antarctic krill, their main prey. Due to this krill abundance, these islands are also an important area for krill fisheries. Due to the establishment of a marine protected area, the fishery is limited by, for example, some areas permanently closed to fishing.

A recent study sought to understand how measures to protect krill and regulate the fishery in this protected area are protecting humpback whales’ feeding grounds. With the use of satellite tags placed near the dorsal fin of humpback whales between 2003 and 2020, it was possible to follow the movements of these whales, from the coast of Brazil, where they reproduce, to the islands of South Georgia and the South Sandwich Islands, where they feed. These movements were then analyzed taking into account the aggregation of krill, and environmental factors (e.g., sea surface temperature, iron concentration, depth, and month).

With these data, it was possible to analyze the existence or absence of humpback whales in various locations and the factors that most influenced their presence in those areas. In the first months of their arrival, the whales were more concentrated in a deep channel of the South Sandwich Island with about 2000 meters, and with high concentrations of iron, which is indicative of high biological productivity, being the possible reason for their presence in this area. As the summer progresses, the whales move to the South Georgia shelf, where >90% of the tagged whales were within the limits of the marine protected area, during a period in which no fishery was taking place. Humpback whales are increasingly frequent in these waters and seem to be recovering to pre-exploitation levels, which is excellent news.

The management of resources in the Southern Ocean does not yet include the various species of whales, unlike penguins, seals, and seabirds, species that also feed on krill. However, in the future, with the right information, it will be possible to move in that direction.

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Source: Bamford, C. C. G., Jackson, J. A., Kennedy, A. K., Trathan, P. N., Staniland, I. J., Andriolo, A., & Zerbini, A. N. (2022). Humpback whale (Megaptera novaeangliae) distribution and movements in the vicinity of South Georgia and the South Sandwich Islands Marine Protected Area. Deep Sea Research Part II: Topical Studies in Oceanography, 198, 105074. https://doi.org/10.1016/j.dsr2.2022.105074

Author: 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

Climate change is real, and satellites have been a valuable tool to measure the effects of rising global temperatures. Additionally, the United Nations UNFCCC has defined a set of multiple variables measurable from space thus gathering great amounts of data. One of these variables is Ocean Colour, which allows us to estimate phytoplankton concentrations in water bodies. Phytoplankton contains chlorophyll, making satellite images of the water surface slightly greener.

Plants are extremely sensitive to changes in temperature patterns. Just like land plants, phytoplankton cycles are sentinels for change. In high-altitude areas, where the temperature is increasing at double the rate of the global average, this is even more dramatic. Phytoplankton provides the basis of the oceanic food web, and its window of opportunity for exponential growth is narrow. These periods of fast algae growth are called blooms. In polar regions, these blooms occur in perfect harmony between ice melt, and greater availability of sunlight.

Previous research has shown that especially in the Arctic blooms occurred up to 50 days earlier in 2009 than in 1997 – the year SeaWiFS started sending the first data. This brings harmful consequences for marine life and carbon dioxide uptake from the atmosphere.

To better monitor phytoplankton from space, is it indispensable to validate ocean colour images with in-situ chlorophyll concentrations. Our research is focusing on Finnish lakes ( Figure 3 ), where we have collected samples from 19 lakes and compared the values with images from satellites that have flown overhead on the same day.

The result of this method is a model from which to estimate chlorophyll concentrations in each satellite pass. These satellites orbit the Planet every 90 minutes, proving to be a fundamental resource to study how climate is changing and its impact on phytoplankton.

There are only two life forms seen from space: land and marine plants, and humans, with their great ingenuity — cities, pollution and deforestation. Although we are not the centre of the Universe, we are responsible for our future, and Earth Observation can help us make better decisions for the future.

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Sources:

H. Schellnhuber, Earth system’analysis and the second Copernican revolution, Nature, vol. 402,

no.December, pp. 19–22, 1999.

M. Kahru et al. 2011, Are phytoplankton blooms occurring earlier in the Arctic?, Global Change

Biology (2011) 17, 1733–1739, doi: 10.1111/j.1365-2486.2010.02312.x.

Lisboa et al. 2018, Spatial variability and detection levels in Chlorophyll-a estimates using Landsat imagery, submitted.

Author: Filipe Lisboa