Argentine Antarctic Institute

The western Antarctic Peninsula is characterized by pronounced climate variability and a high concentration of human activities, including tourism and fishing. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), the body responsible for the conservation of Antarctic marine ecosystems and for regulating fisheries south of the Antarctic Convergence, considers Pygoscelis penguins to be key ecosystem indicator species. In this study, we used stomach content analysis and tracking data to examine diet composition and foraging parameters of chinstrap (Pygoscelis antarcticus) and gentoo (Pygoscelis papua) penguins breeding in two colonies at Cierva Cove, Gerlache Strait (64°08′ S, 60°59′ W and 64°10′ S, 60°56′ W, respectively). Our aim was to identify their main prey and the areas they use during foraging trips in the chick-rearing period of the 2024/25 breeding season. Antarctic krill (Euphausia superba) dominated the diet of both species; however, chinstrap penguins consumed smaller krill than gentoo penguins. Tracking data showed that both species foraged in coastal areas, with chinstrap penguins undertaking shorter trips, both distance and duration than their congeners. This study provides updated, spatially explicit ecological information to support management and conservation in the Gerlache Strait, a region increasingly pressured by krill fisheries.

The aquifer system of Deception Island, located in the South Shetlands archipelago, exhibits high transmissivity given the hydraulic conductivity of the pyroclastic sediments that form the aquifer, promoting both high infiltration of meteoric water and rapid groundwater flow. Recharge to the aquifer is primarily driven by snowmelt and precipitation, with a mean annual recharge estimated at 164 mm/yr, representing 41% of the island's average annual precipitation (P = 400 mm/yr). The remaining water is lost through evaporation (142 mm/yr and 35%P) and wind-driven snow transport (95 mm/yr and 24%P). The aquifer system is characterized by a shallow, seasonally active unconfined aquifer within the permafrost's active layer, and a highly transmissive permanent aquifer mainly beneath the permafrost. Both aquifers are generally unconfined, but the lower one may become locally confined near the coast due to permafrost. Groundwater discharge maintains the studied lake at levels above sea level (by less than 1 m), preventing salinization and ensuring that they remain fresh despite being located in a morphologically closed volcanic basin. Hydrochemical and isotopic analyses reveal that lake water composition is influenced by marine aerosol deposition, convergence of groundwater flow lines, and proximity to the sea. These findings highlight the dynamic interplay between volcanic geology, permafrost, and hydrogeological processes in sustaining freshwater lake systems in an Antarctic volcanic environment.

The foraging behavior of bioindicator species, such as penguins, provides valuable insights into ecosystem functioning, helping to assess the potential effects of environmental variability and identify priority areas for their conservation. At Stranger Point/Cabo Funes (South Shetland Islands), Antarctic krill (Euphausia superba) dominates the diet of chick-provisioning Adélie (Pygoscelis adeliae) and gentoo (Pygoscelis papua) penguins. However, the marine areas used by these species had not previously been studied using GPS loggers. During the 2017/2018 chick-guarding stage, we tracked the horizontal movements of both species. The individuals predominantly moved southeast of the colony, remaining in nearby coastal habitats within the Mar de la Flota/Bransfield Strait. Maximum and total distance traveled, as well as foraging trip duration, did not differ significantly between species. However, differences were observed in trip departure times, with gentoo penguins departing earlier in the morning than Adélie penguins. Both species overlapped in their home range areas, but there was evidence of some spatial segregation: foraging effort of gentoo penguins was more concentrated closer to the colony than that of Adélie penguins. In contrast, no significant differences in trip parameters were observed in either species as the breeding stage progressed, suggesting that krill was not a limited resource during the 2017/2018 season. In line with this, no interspecific differences in breeding success were detected. Our results underline the ecological value of the coastal waters off Stranger Point, where a seamount lies about 20 km offshore, as productive foraging grounds and reinforce the importance of conserving these key habitats.

Moisture intrusions, including Antarctic atmospheric rivers (AARs) and cyclonically driven transport, are major drivers of cloud-layer development and thermodynamic variability over the Antarctic Peninsula, yet their influence on turbulence and vertical mixing remains poorly constrained. Here we investigate how moisture and phase changes modulate turbulence using 32 high-resolution radiosonde soundings, complemented by in situ supercooled liquid water measurements, collected during the T-SCAN campaign at Marambio Base, located north of the Antarctic Peninsula, during the 2025 austral summer. Enhanced moisture conditions are associated with deep saturated and ice-supersaturated layers extending up to 6–8 km, with supersaturation with respect to ice accounting for ˜60% of saturated layers on average, and up to ˜90% in individual cases. Accounting for moist thermodynamics reduces estimations of static stability and increases turbulent overturning scales, with moist turbulent fractions exceeding dry estimates in 31 of the 32 soundings. These fractions reach ˜60–70% in the strongest cases and exceed 40% in 72% of the soundings. The troposphere is predominantly ice-phase above ˜1 km, with only intermittent supercooled liquid water in shallow layers. These results show that moist processes substantially enhance diagnosed turbulence during Antarctic moisture-intrusion regimes, including AAR conditions, and that neglecting them leads to a systematic underestimation of vertical mixing in polar environments.

Antarctic ecosystems host psychrophilic and psychrotolerant fungi whose set of adaptations represents a biotechnologically valuable and underexploited genetic resource. This review synthesizes the current literature on the bioactive secondary metabolites and cold-active enzymes produced by Antarctic fungi, together with their biomedical, cosmetic, and industrial applications, and examines the regulatory and ethical framework governing their exploitation under the Antarctic Treaty System. Antioxidant, antimicrobial, anti-inflammatory, and photoprotective compounds—together with cold-active lipases, proteases, and amylases—were identified as the main classes of biotechnologically relevant molecules, with the Cadophora genus and the lipase B of Moesziomyces antarcticus (Candida antarctica) (CALB) highlighted as paradigmatic cases. Evidence considered shows that, despite promising bioactivities and at least one globally commercialized product (CALB/Novozym®), most findings remain confined to the academic level, revealing an early-stage translational field. The CALB case further exposes an unresolved regulatory gap: minimal, non-destructive sampling can generate substantial commercial value without any derived benefit for either the country of the researchers involved in the isolation, Antarctica, or the international community. These findings underscore the need for a specific legal instrument within the Antarctic Treaty System establishing rational bioprospection guidelines and mechanisms for equitable benefit-sharing.