Impact of the harsh Antarctic environment on mucosal immunity

Mucosal immunity of Indian Antarctic personnel was analysed during the 34th Indian Scientific Expedition to Antarctica (ISEA) by ship voyage. Serum and salivary IgA, IgA1 and IgA2 levels along with salivary cortisol and TGF-β were quantified by enzyme-linked immunosorbent assay. Samples were collected at three different time points (T1, T2 and T3) during the expedition. Serum and salivary IgA, IgA1 and IgA2 concentrations incrementally increased towards the end of the expedition as compared to the beginning of the expedition. Salivary IgA and TGF-β levels were significantly altered during the expedition. Levels of IgA1 (P = 0.0007) and IgA2 (P = 0.0135) increased significantly at T3 as compared to T1. Additionally, significant changes in serum IgA were observed, with peak levels at T3 (P = 0.0015) and T2 (P < 0.001). However, the level of serum IgA2 was also significantly altered at T3 (P < 0.05) and T2 (P = 0.0006) in comparison with T1. The exact cause of the changes in serum and salivary IgA, IgA1, IgA2 and TGF-β levels during the summer expedition are unknown; however, the changes are evident in mucosal immunity.

Bacteria Isolated From the Antarctic Sponge Iophon sp. Reveals Mechanisms of Symbiosis in Sporosarcina, Cellulophaga, and Nesterenkonia

Antarctic sponges harbor a diverse range of microorganisms that perform unique metabolic functions for nutrient cycles. Understanding how microorganisms establish functional sponge–microbe interactions in the Antarctic marine ecosystem provides clues about the success of these ancient animals in this realm. Here, we use a culture-dependent approach and genome sequencing to investigate the molecular determinants that promote a dual lifestyle in three bacterial genera Sporosarcina, Cellulophaga, and Nesterenkonia. Phylogenomic analyses showed that four sponge-associated isolates represent putative novel bacterial species within the Sporosarcina and Nesterenkonia genera and that the fifth bacterial isolate corresponds to Cellulophaga algicola. We inferred that isolated sponge-associated bacteria inhabit similarly marine sponges and also seawater. Comparative genomics revealed that these sponge-associated bacteria are enriched in symbiotic lifestyle-related genes. Specific adaptations related to the cold Antarctic environment are features of the bacterial strains isolated here. Furthermore, we showed evidence that the vitamin B5 synthesis-related gene, panE from Nesterenkonia E16_7 and E16_10, was laterally transferred within Actinobacteria members. Together, these findings indicate that the genomes of sponge-associated strains differ from other related genomes based on mechanisms that may contribute to the life in association with sponges and the extreme conditions of the Antarctic environment.

Science and Policy Interactions in Assessing and Managing Marine Ecosystems in the Southern Ocean

Good policy can only be built and implemented using sound advice, and a clear understanding of risk. Scientific advice will often be qualified by the extent of research and knowledge, and uncertainties about the current and future state of the environment. Bodies tasked with protecting the Antarctic environment are required to make decisions based on the best available advice. To not take decisions in the absence of certainty is contrary to clear obligations to protect the Antarctic environment contained in the instruments of the Antarctic Treaty System. The risk of foreclosing future options to protect the environment by indecision is as great, if not greater, than making decisions with incomplete advice, and then actively managing that decision into the future. This “Perspective” explores the relationship between science and policy in the context of the Conference on Marine Ecosystem Assessment for the Southern Ocean held in 2018—it is a perspective from the view of a policy-maker and end user of scientific assessment and advice.

Icebreaking polar class research vessels: New Antarctic fleet capabilities

Supporting Antarctic scientific investigation is the job of the national Antarctic programmes, the government entities charged with delivering their countries’ Antarctic research strategies. This requires sustained investment in people, innovative technologies, Antarctic infrastructures, and vessels with icebreaking capabilities. The recent endorsement of the International Maritime Organization (IMO) Polar Code (2015) means that countries must address challenges related to an ageing icebreaking vessel fleet. Many countries have recently invested in and begun, or completed, builds on new icebreaking Polar research vessels. These vessels incorporate innovative technologies to increase fuel efficiency, to reduce noise output, and to address ways to protect the Antarctic environment in their design. This paper is a result of a Council of Managers of National Antarctic Programs (COMNAP) project on new vessel builds which began in 2018. It considers the recent vessel builds of Australia’s RSV Nuyina, China’s MV Xue Long 2, France’s L’Astrolabe, Norway’s RV Kronprins Haakon, Peru’s BAP Carrasco, and the United Kingdom’s RRS Sir David Attenborough. The paper provides examples of purposeful consideration of science support requirements and environmental sustainability in vessel designs and operations.

Identification of Phyllosilicates in the Antarctic Environment Using ASTER Satellite Data: Case Study from the Mesa Range, Campbell and Priestley Glaciers, Northern Victoria Land

In Antarctica, spectral mapping of altered minerals is very challenging due to the remoteness and inaccessibility of poorly exposed outcrops. This investigation evaluates the capability of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite remote sensing imagery for mapping and discrimination of phyllosilicate mineral groups in the Antarctic environment of northern Victoria Land. The Mixture-Tuned Matched-Filtering (MTMF) and Constrained Energy Minimization (CEM) algorithms were used to detect the sub-pixel abundance of Al-rich, Fe3+-rich, Fe2+-rich and Mg-rich phyllosilicates using the visible and near-infrared (VNIR), short-wave infrared (SWIR) and thermal-infrared (TIR) bands of ASTER. Results indicate that Al-rich phyllosilicates are strongly detected in the exposed outcrops of the Granite Harbour granitoids, Wilson Metamorphic Complex and the Beacon Supergroup. The presence of the smectite mineral group derived from the Jurassic basaltic rocks (Ferrar Dolerite and Kirkpatrick Basalts) by weathering and decomposition processes implicates Fe3+-rich and Fe2+-rich phyllosilicates. Biotite (Fe2+-rich phyllosilicate) is detected associated with the Granite Harbour granitoids, Wilson Metamorphic Complex and Melbourne Volcanics. Mg-rich phyllosilicates are mostly mapped in the scree, glacial drift, moraine and crevasse fields derived from weathering and decomposition of the Kirkpatrick Basalt and Ferrar Dolerite. Chlorite (Mg-rich phyllosilicate) was generally mapped in the exposures of Granite Harbour granodiorite and granite and partially identified in the Ferrar Dolerite, the Kirkpatrick Basalt, the Priestley Formation and Priestley Schist and the scree, glacial drift and moraine. Statistical results indicate that Al-rich phyllosilicates class pixels are strongly discriminated, while the pixels attributed to Fe3+-rich class, Fe2+-rich and Mg-rich phyllosilicates classes contain some spectral mixing due to their subtle spectral differences in the VNIR+SWIR bands of ASTER. Results derived from TIR bands of ASTER show that a high level of confusion is associated with mafic phyllosilicates pixels (Fe3+-rich, Fe2+-rich and Mg-rich classes), whereas felsic phyllosilicates (Al-rich class) pixels are well mapped. Ground truth with detailed geological data, petrographic study and X-ray diffraction (XRD) analysis verified the remote sensing results. Consequently, ASTER image-map of phyllosilicate minerals is generated for the Mesa Range, Campbell and Priestley Glaciers, northern Victoria Land of Antarctica.

Mini review on phenol biodegradation in Antarctica using native microorganisms

Though Antarctica has once been considered as the most pristine land on earth, however, recently many literatures concluded that it is not a zone free from anthropogenic pollutants, which have been mostly associated with long-range atmospheric transport and deposition in the area. Numerous organic pollutants including phenol have been classified as the priority pollutants by the United States Environmental Protection Agency (US EPA) due to their high toxicity. The increased level of phenol concentration in the Antarctic environment poses a significant risk to the aquatic as well as terrestrial lives and public health due to its persistence, biomagnification and accumulation in the food chain. Therefore, bioremediation actions are significant to overcome this problem. Phenol degradation at cold climate needs the use of microorganisms that has the ability to thrive and function at low temperatures as well as withstand the toxicity of phenol. The utilisation of native microbes as phenol-degraders has proven the effectiveness of bioremediation even though phenol has anti-microbial properties. This paper discusses the sources and toxicity of phenol, existence and effect of phenol on the Antarctic environment, the potential method for eliminating phenol from the environment and suggestion for future prospect.