Programa Antártico Colombiano - Comisión Colombiana del Océano

Es el proyecto de Estado que coordina las actividades científicas y complementarias del país en el Continente Antártico; su propósito incluye promover las ciencias antárticas, procurar la protección y conservación ecosistémica, e incentivar el intercambio y la transferencia de información, conocimiento técnico y capacidades científicas.

El PAC promueve el interés nacional y la presencia efectiva de Colombia en la Antártida, así como la participación dinámica e influyente en las decisiones que se tomen en el marco del Sistema del Tratado Antártico (STA).

Colombia en la Antártida

Vinculación al STA: Favorecer la participación plena en las instancias derivadas del STA y el fomento de la cooperación internacional para cumplir con los propósitos del Tratado Antártico.

Interés nacional: Promover la salvaguarda de la Antártida como un continente de paz y de ciencia, y comprender las conexiones con el territorio colombiano.

Contribución a las ciencias antárticas: Aportar a la investigación científica relacionada con los fenómenos del continente antártico y sus ecosistemas dependientes y asociados.

Convocatoria
Información producción científica

					Año
wdt_ID	wdt_created_by	wdt_created_at	wdt_last_edited_by	wdt_last_edited_at	Año	Título	Investigadores	Palabras clave	Resumen	link	Doi
1					1976	Relationship of Radiolarian Assemblages to Sediment Types and Physical Oceanography in the Atlantic and Western Indian Ocean Sectors of the Antarctic Ocean	Jose A. Lozano, James D. Hays		The relative abundances of 18 selected taxonomic groups of Radiolaria were determined for 145 trigger-weight core-top samples collected between long 80°E and 55°W and lat 35°S and 60°S. Seventy-two samples were considered to represent nonreworked recent sediments. A factor analysis of these 72 samples resolved Antarctic, subantarctic, and subtropical assemblages, with distributions closely corresponding to the main surface water masses in the area. Using the technique of Imbrie and Kipp, paleoecologic equations have been developed to estimate surface-water temperatures for August (winter) and February (summer). Estimated temperatures range from near 20°C in the northern parts of the area to 0°C at the location of the southernmost cores. The standard error of estimate of the equations is less than 1.5°C. The CaCO3 content of the 145 surface-sediment samples shows that variations in the calcite compensation depth (CCD) for locations north of the Antarctic Polar Front depends mainly on varying dissolution. The CCD is about 4,800 m in the western basin of the Atlantic Ocean but is deeper than 5,200 m, at least locally, in the Indian Ocean. South of the Antarctic Polar Front the CCD is shallower than 3,700 m. Radiolaria are common in most samples, with the maximum number per gram of sediment being found in samples collected near or beneath the Antarctic Polar Front.
2					1990	Whale migration record	STONE, G., FLOREZ-GONZALEZ, L. & KATONA, S		SIR-We recently confirmed a new long distance migration record for mammals (apart from Homo sapiens). We found that a humpback whale (Megaptera novaeangliae) has migrated from the Antarctic peninsula region (64° 20’S; 62° 27’W) to Colombia (2° 57’N; 78° 12’W). The shortest swimming distance between these locations is more than 8,334 kilometres. We identified the whale at both locations using photographs of the distinctive ventral pigmentation on the tail flukes’. The whale was seen in Antarctica on 19 April and in Colombia on 28 August 1986. This is the first time that a hump back whale has been shown to cross the equator, and the first time an Antarctic humpback whale has been documented in South American waters. This finding has interesting implications for the possibility of migration between hemispheres. The match of pigmentation was found by comparing a catalogue of 32 hump backs identified from the Antarctic penin sula’ and a collection of 86 identified off the coast of Colombia. The whale swam from Antarctica to Colombia in less than 5 months. Following the typical hump back migration strategy of spending sum mer in high latitudes and winter in low latitudes’, this whale probably belongs to a population that feeds in Antarctica and breeds off the coast of Colombia. It is also possible that Antarctic penin sula humpback whales migrate up the eastern side of South America to the coast of Brazil, where there is another breeding ground. The swimming distance from the Antarctic peninsula to this area is shorter by more than 1,800 kilometres than to the Colombian site. This raises the interesting possibility that the Antarctic peninsula feeding grounds may be an area from which humpback whales can cross between the South Pacific Ocean and the South Atlantic Ocean. It is of interest to note that only 1,000 kilometres further north of our Colombian study site there is a site used during the breeding season by possibility that individuals occasionally might do so has important implications for gene flow, population differentiation and population management, and deserves further study.
3					2001	Genetic characterisation of the Colombian Pacific Coast humpback whale population using RAPD and mitochondrial DNA sequences	Caballero, S., Hamilton. H., Jaramillo, C., Capella, J., Flórez-González, L., Olavarría, C., Rosenbaum, H., Guhl, F. & Baker, C.S.	Megaptera novaeangliae, population structure, RAPD, mitochondrial DNA	Two genetic techniques were used to characterise the humpback whale population that overwinters annually off the Pacific Coast of Colombia. A preliminary study applied molecular techniques to an initial set of 32 biopsied or sloughed skin samples. Randomly Amplified Polymorphic DNA (RAPD) was used to provide an estimate of genetic variability and intra-population structure. Diversity of RAPD banding patterns suggest substantial genetic variability among sampled individuals. A parsimony tree was constructed using presence/absence of RAPD bands as characters, revealing three distinct groups: one of closely related individuals separate from two distinct clades within which relationships were unresolved. Mitochondrial DNA sequences for a consensus fragment 283 base pair in length of the rapidly evolving mitochondrial control region were then generated for the 32 samples and an additional 48 skin samples obtained from further fieldwork. An extensive comparative analysis was made with both published and unpublished control region sequences from humpback whales previously sampled in Colombia (n=64) and other regions in the Southern hemisphere (n=193) and the North Pacific (n=21). Haplotype diversity of the Colombian humpback population was high relative to other sampled populations, with 37 distinctive haplotypes, 11 of which were represented by a single animal. Both RAPD and mtDNA sequence data suggest further genetic substructure within the Colombian Pacific Coast humpback whale population. A large proportion of haplotypes (n=17) are shared with humpback whales sampled off the Antarctic Peninsula, suggesting a strong migratory connection between these regions as reported elsewhere. Only three haplotypes were shared with other Southern Hemisphere breeding grounds. Two Colombian haplotypes were common to populations from the North Pacific, supporting the hypothesis of a past or present East Pacific gene flow corridor between Northern and Southern Hemisphere populations.
4					2003	Late Devonian acanthodians from Colombia	Burrow, C., Janvier, P., & Villarroel, C.	Acanthodii; Cuche Formation; frasnian; Devonian; Colombia	Acanthodian remains occur in micaceous siltstone lenses (presumed to have been deposited during a marine incursion) in the Cuche Formation (?Frasnian) of northeast Colombia. The acanthodians are represented by patches of scales from climatiidid Nostolepis sp. cf. N. gaujensis and a fin spine and scales from a new diplacanthid. Type material of N. gaujensis is from the Frasnian Sventoji regional stage in the Baltic, and Nostolepis sp. cf. N. gaujensis has been recorded in the Frasnian of Iran, as well as from Colombia. The new diplacanthid taxon shows affinity to Baltic and Antarctic diplacanthids. The fauna thus shows possible links to both Gondwanan and Euramerican acanthodian assemblages.
5					2007	Migratory destinations of humpback whales from the Magellan Strait feeding ground, Southeast Pacific	Acevedo, J., Rasmussen, K., Félix, F., Castro, C., Llano, M., Secchi, E., Saborío M., Aguayo-Lobo, A., Ben Haase., et al.		Latitudinal preferences within the breeding range have been suggested for Breed- ing Stock G humpback whales that summer in different feeding areas of the eastern South Pacific. To address this hypothesis, humpback whales photo-identified from the Antarctic Peninsula and the Fueguian Archipelago (southern Chile) were com- pared with whales photo-identified from lower latitudes extending from northern Peru to Costa Rica. This comparison was performed over a time span that includes 18 austral seasons. A total of 238 whales identified from the Antarctic Peninsula and 25 whales from the Fueguian Archipelago were among those photo-identified at the breeding grounds. Our findings showed that humpback whales from each feeding area were resighted unevenly across the breeding grounds, which suggests a degree of spatial structuring in the migratory pathway. Humpback whales that feed at the Antarctic Peninsula were more likely to migrate to the southern breeding range between northern Peru and Colombia, whereas whales that feed at the Fueguian Archipelago were more likely to be found in the northern range of the breeding ground off Panama. Further photo-identification efforts and genetic sampling from poorly sampled or unsampled areas are recommended to confirm these reported con- nectivity patterns.
6					2008	Migratory round-trip of individually identified humpback whales at the Strait of Magellan: clues on transit times and phylopatry to destinations	Capella, J., Gibbons, J., Florez González, L., Llano, M., Valladares, C., Sabaj Diez, V. y Vilina, Y.	Colombia, humpback whales, migration, photo-identification, Strait og Magellan	Humpback whales undertake seasonal migration between productive high-latitude areas where they feed in summer and low-latitude tropical waters where mating and calving occur during winter. In the eastern south Pacific, the species breeds off Colombia and Ecuador, and feeds primarily in the western Antarctic Peninsula and in the waters of the Strait of Magellan (SM), recently described as a new feeding ground for humpback whales. Comparison of fluke photographs of 62 individuals from the SM obtained during the austral summer from 1999 to 2005 and 1,042 individuals from Colombia, provided conclusive matches for six individuals, with an overall interchange index of 0.093. Eight migratory trips between summer and winter grounds were registered for four whales during a complete migratory round-trip in consecutive years. The minimum distance traveled in a one-way trip ranged from 6,650 to 7,000 kill. The duration of the two fastest trips between these migratory destinations was 88 and 99 days, with a mean speed of migration of 76 and 67 kill day(-1) respectively. Five of the whales present in both areas were males and three mitochondrial DNA haplotypes were identified: EM-1 for three individuals, EM-2 for two and EM-3 for the last one, all of which have been previously described for humpback whales from Colombia. All six individuals were seen several days in each season in the SM (as many as 39 days in one case), with in average stay of 72 40 days (n = 20) per year, ranging from 3 to 125 days. On average, each of the six individuals was seen in the SM during 7 1 18% of the seven monitored summers. Three individuals were re-sighted in the SM six out of the seven surveyed years, during four to Six Consecutive years. These results provide the first direct evidence to include humpback whales that feed in the Strait of Magellan as part of the eastern south Pacific population of whales that feed off Colombian waters.
7					2008	Using Mitochondrial DNA and Mixed-Stock Analysis to estimate Migratory Allocation of Humpback Whales from Antarctic Feeding Areas to South Pacific Breeding Grounds	R. Albertson-Gibb, C.C. Olavarría, C. Garrigue, N. Hauser, M. Poole, Lilian Flórez-González, C. Antolik, D. Steel & C.S. Baker		We present mixed-stock analyses of mtDNA haplotypes for allocation of humpback whales (Megaptera novaeangliae) from three Antarctic feeding areas to low-latitude breeding grounds. These breeding grounds include New Caledonia, Tonga, Cook Islands, French Polynesia, Colombia and Western Australia. Migratory allocation was estimated using the program Statistics Program for Analyzing Mixtures (SPAM) with an expanded dataset of mtDNA haplotypes from breeding grounds of the South Pacific and Western Australia (n = 1,072, Olavarría et al. (2007)) and a more limited number of samples from Antarctic feeding Areas IV, VI, and I (n=144). Assuming that the breeding grounds represent the ‘pure stocks’ and that each feeding area represent the ‘mixed stocks’ Area IV was allocated in nearly equal proportions to Western Australia (33.1%) and New Caledonia (31.0%), Area VI* whales were allocated primarily to Tonga (78.9%) and Area I* was allocated primarily to Colombia (78.3%).
8					2012	Genetic diversity and population structure of humpback whales(Megaptera novaeangliae) from Ecuador based on mitochondrialDNA analyses	Félix, F., Caballero, S., & Olavarría, C.	Humpback whale, genetics, breeding grounds, South America, breeding stock G	Information on the genetic characterisation of humpback whales (Megaptera novaeangliae) wintering off Ecuador (Breeding Stock G) is presented. Mitochondrial DNA was extracted and sequenced from 230 skin samples collected between 2002 and 2008 to establish the genetic diversity of this population. From 182 usable samples, 41 different haplotypes were found, eight of which were new and unique. Haplotype diversity (h ± SD) was estimated to be 0.922 ± 0.012 and the nucleotide diversity (π ± SD) 0.019 ± 0.009. A comparison with other areas within the Southeast Pacific (Colombia and Magellan Strait) and the Antarctic Peninsula suggested panmixia within Breeding Stock G, even though significant differentiation was found with Magellan Strait (p < 0.0001 in both FST and ΦST). An additional analysis with the exact test of population differentiation showed significant differences in haplotype frequencies between breeding areas in Ecuador and southern Colombia (p < 0.01), suggesting some level of stratification at breeding grounds as supported by photo-identification studies. The Ecuadorian dataset included haplotypes reported in all three Southern Hemisphere ocean basins indicating recent gene flow within the Southern Hemisphere. The population showed a male-biased sex ratio in adult animals of 2.16:1. Further research and a larger number of samples from breeding areas in the north (Panama and Costa Rica) are required to appropriately assess the extent of structure in this population.
9					2013	La Bioprospección Antártica: indefiniciones e incompatibilidades con el sistema del tratado Antártico	Villamizar-Lamus, F.	Antarctic, jurisdiction, law, biotechnology, borders, scientific research, antarctic biological prospection, Antarctic Treaty, lack of definitions and incompatibilities	Pese a que las partes de la Reunión Consultiva del Tratado Antártico de 2009 consideraron que la bioprospección antártica estaba regulada de forma adecuada por la legislación antártica vigente, el presente artículo demuestra que existen problemas jurídicos respecto de la definición de conceptos fundamentales así como posibles incompatibilidades con principios básicos del Tratado Antártico que aún no están resueltas, de manera que haya claridad jurídica para realizar actividades de bioprospección en la Antártida.
10					2014	Molecular systematics of the deep-sea bamboo corals (Octocorallia: Isididae: Keratoisidinae) from New Zealand with descriptions of two new species of Keratoisis	Dueñas, LF., Alderslade, P., & Sánchez, JA.	Antarctica, Large sub-unit rRNA 16S, Octocoral, Taxonomy, igr4, mtMutS.	Bamboo corals belong to a species rich and abundant group of octocorals that occur throughout the world’s oceans, primarily in the deep-sea. Their study through morphological, ecological and evolutionary approaches has been problematic because of the extreme environments many of them inhabit and therefore the difficulty of obtaining good quality samples. However, new undescribed species have been commonly collected as part of invertebrate by-catch studies from commercial fisheries. In this study we describe two new species of deep-sea bamboo corals from New Zealand waters, including the Ross Sea (Antarctica) using morphological and molecular approaches. For the morphological description we used macro-structural characters such as branching pattern, color and polyp arrangement, along with axis architecture and sclerite shape and arrangement. The new species fit in the subfamily Keratoisidinae and the genus Keratoisis. Keratoisis magnifica n.sp. is characterized by having big, highly armed conical polyps and K. peara n.sp. has long, smooth internodes with an unusual nacreous lustre. Additionally, we amplified three mitochondrial genes (16S, igr4 and mtMutS), and obtained optimal topologies through maximum likelihood and Bayesian approaches. The resulting molecular phylogenies corroborated the status of the new taxa and elucidated their relationships to closely related species. Additionally, we show further genetic evidence that branching pattern, as previously thought, could be an unreliable character not only for Lepidisis/Keratoisis, but also for other genera within the Keratoisidinae.
11					2015	Un modelo hidrodinámico del estrecho de Gerlache (Antártida) para el verano del hemisferio sur	Lonin, S.	Estrecho Gerlache, modelo hidrodinámico, témpanos de hielo.	La Primera Expedición Científca de Colombia en la Antártida fue realizada durante el verano del hemisferio sur (enero-febrero de 2015) en el área del estrecho de Gerlache, ubicado en la península Antártica. La información oceanográfca e hidrográfca recolectada durante el crucero permitió implementar un modelo hidrodinámico bajo las condiciones de deshielo con el fn de estudiar los procesos hidrofísicos en el área de estudio con posterior aplicación del modelo a las predicciones del tiempo y el movimiento de los témpanos de hielo. Se formula el modelo hidrodinámico, haciendo énfasis en la descripción matemática de una compleja morfología, con presencia de sistemas de fordos, islas y pasillos angostos. Se analizó el régimen de la marea astronómica, siendo de mayor importancia en la dinámica del estrecho en comparación con las corrientes termohalinas y la deriva de viento para este período del año.
12					2015	Avistamiento de Hielos sobre el Mar en la Bahía de Fildes y el Estrecho de Gerlache durante el Verano Austral 2015	Trujillo, J., Ramírez Cárdenas, J., Vargas, M., Adames Prada, R., & Murillo Gómez, N.	Hielo-Marino, Carta-de-hielos, Verano-Austral	Durante la Primera Expedición Científica de Colombia a la Antártica, desde el buque ARC “20 de Julio” y desde el helicóptero ARC 255, se tomaron registros fotográficos de los hielos avistados sobre el mar. Los hielos fotografiados se identificaron y clasificaron usando la terminología de hielos avalada por la Organización Marítima Mundial (OMM), la Carta de Hielos Antárticos del Servicio Hidrológico y Oceanográfico de la Armada de Chile (SHOA) y el Manual de hielo del Servicio de Hielo Canadiense (MANICE por sus siglas en inglés de Manual of Ice). Se corrobora el comportamiento de la dinámica de deshielo propia del verano austral en la Bahía de Fildes y el Estrecho de Gerlache.
13					2015	Characterization of the Antarctic sea urchin (Sterechinus neumayeri) transcriptome and mitogenome: a molecular resource for phylogenetics, ecophysiology and global change biology	Dilly, G., Gaitán-Espitia, J., & Hofmann, G.E.	Antarctica, Sterechinus neumayeri, echinoids, mitogenome, ocean acidification, transcriptomics.	This is the first de novo transcriptome and complete mitochondrial genome of an Antarctic sea urchin species sequenced to date. Sterechinus neumayeri is an Antarctic sea urchin and a model species for ecology, development, physiology and global change biology. To identify transcripts important to ocean acidification (OA) and thermal stress, this transcriptome was created pooling, and 13 larval samples representing developmental stages on day 11 (late gastrula), 19 (early pluteus) and 30 (mid pluteus) maintained at three CO2 levels (421, 652, and 1071 μatm) as well as four additional heat-shocked samples. The normalized cDNA pool was sequenced using emulsion PCR (pyrosequencing) resulting in 1.34M reads with an average read length of 492 base pairs. 40 994 isotigs were identified, averaging 1188 bp with a median coverage of 11×. Additional primer design and gap sequencing were required to complete the mitochondrial genome. The mitogenome of S. neumayeri is a circular DNA molecule with a length of 15 684 bp that contains all 37 genes normally found in metazoans. We detail the main features of the transcriptome and the mitogenome architecture and investigate the phylogenetic relationships of S. neumayeri within Echinoidea. In addition, we provide comparative analyses of S. neumayeri with its closest relative, Strongylocentrotus purpuratus, including a list of potential OA gene targets. The resources described here will support a variety of quantitative (genomic, proteomic, multistress and comparative) studies to interrogate physiological responses to OA and other stressors in this important Antarctic calcifier.
14					2015	Colombia: ¿Miembro Consultativo del Tratado Antartico?	Guzmán, D. A	Tratado Antártico, relaciones internacionales	Las relaciones internacionales de Colombia durante el siglo XX, fueron marcadas esencialmente por dos doctrinas, la doctrina réspice polum, que se alineaba de forma casi irreflexiva a la política exterior de los Estados Unidos y la cual hasta los años noventa, estuvo particularmente marcada por la lucha anticomunista; y la doctrina réspice similia2 (Tokatlian, 2000), que trató de acercarse más a los países latinoamericanos. A pesar que bajo estas dos doctrinas Colombia participó en diferentes escenarios internacionales y suscribió varios tipos de tratados mundiales y regionales, su protagonismo fue escaso, debido en gran parte a la ausencia de intereses nacionales permanentes que guiaran los objetivos de una política exterior consistente. Una de las participaciones internacionales de Colombia, en las cuales hasta hace pocos años no ejerció ninguna acción efectiva, es en el Tratado Antártico (TA).
15					2015	Distinct composition signatures of archaeal and bacterial phylotypes in the Wanda Glacier forefield, Antarctic Peninsula	Pessi, I.S., Osorio-Forero, C., Gálvez, E.J., Simões, F.L., Simões, J.C., Junca, H., Macedo, A.J.	Microbial diversity, Next-generation sequencing, Recently deglaciated environments	Several studies have shown that microbial communities in Antarctic environments are highly diverse. However, considering that the Antarctic Peninsula is among the regions with the fastest warming rates, and that regional climate change has been linked to an increase in the mean rate of glacier retreat, the microbial diversity in Antarctic soil is still poorly understood. In this study, we analysed more than 40 000 sequences of the V5-V6 hypervariable region of the 16S rRNA gene obtained by 454 pyrosequencing from four soil samples from the Wanda Glacier forefield, King George Island, Antarctic Peninsula. Phylotype diversity and richness were surprisingly high, and taxonomic assignment of sequences revealed that communities are dominated by Proteobacteria, Bacteroidetes and Euryarchaeota, with a high frequency of archaeal and bacterial phylotypes unclassified at the genus level and without cultured representative strains, representing a distinct microbial community signature. Several phylotypes were related to marine microorganisms, indicating the importance of the marine environment as a source of colonizers for this recently deglaciated environment. Finally, dominant phylotypes were related to different microorganisms possessing a large array of metabolic strategies, indicating that early successional communities in Antarctic glacier forefield can be also functionally diverse.
16					2015	Propuesta Preliminar para la Instalacion de una Base Temporaria olombiana en la Antartida	Urrego-Niño D., Torres-Parra R.R, Ricardo Melendez D.	Base Temporaria Colombia, Marambio	Como parte de este proyecto se desarrollaron actividades en dos bases Argentinas: Marambio (Anexo P), permanente y Petrel (Anexo Q), temporaria. Esta investigación permitió caracterizar los tipos de infraestructuras antárticas, organización y principales aspectos logísticos a tener en cuenta en estas bases. Se analizó la importancia de las bases para sostener de manera segura las investigaciones que se desarrollan en el continente blanco, que finalmente son la razón de su existencia. Se incluyó un análisis del procedimiento argentino para la aprobación y ejecución de proyectos de investigación científica en la Antártida, como referencia al procedimiento que se desarrolla en el Programa Antártico Colombiano
17					2015	Análisis comparativos de corte y soldadura submarina aplicada en ambientes extremos de bajas temperaturas vs los utilizados en el trópico, cuyos resultados permitirán el posible desarrollo de nuevas técnicas, procedimientos y herramientas	Patiño Reyne A	Soldadura, Ambientes Extremos, Bajas Temperaturas	Un buzo de la Armada colombiana investigó en una base argentina las características generales del buceo en aguas polares, para definir los elementos necesarios, protocolos de seguridad y otros requerimientos básicos para desarrollar actividades submarinas en la Antártida, temas de gran importancia para el manejo de emergencias y averías de buques. Con la información recolectada se establecen las bases para continuar con otras fases del proyecto de forma eficiente y segura (Anexo C)
18					2016	Genetic differentiation between humpback whales (Megaptera novaeangliae) from Atlantic and Pacific breeding grounds of South America	Cypriano-Souza, A ., Engel, M. H., Caballero, S., Olavarría, C., Flórez-González, L., Capella, J., Steel, D., Sremba, A., Aguayo, A., Thiele, D., Baker, C. S., Bonatto, S. L.	Megaptera novaeangliae, population genetic structure, microsatellites, mtDNA, migration, individual assignment.	Humpback whales wintering in tropical waters along the Atlantic and Pacific coasts of the South American continent are thought to represent distinct populations or “stocks.” Here we present the first analysis of genetic differentiation and estimates of gene flow between these breeding stocks, based on both mitochondrial DNA (mtDNA) control region sequences (465 bp) and 16 microsatellite loci from samples collected off Brazil (n = 277) and Colombia (n = 148), as well as feeding areas near the western Antarctic Peninsula (n = 86). We found significant differentiation between Brazilian and Colombian breeding grounds at both mtDNA (FST = 0.058) and microsatellite (FST = 0.011) markers and corroborated previous studies showing genetic similarity between humpbacks from Colombia and those from Antarctic Peninsula feeding areas. Estimates of long-term gene flow between Brazil and Colombia were low to moderate, asymmetrical, and mostly mediated by males. Assignment procedures detected some cases of interchange and individuals of admixed ancestry between breeding grounds, indicating limited mixing of individuals between these stocks. Overall, results highlight the differentiation of humpback whale breeding populations with adjacent feeding grounds. This appears to be a remarkable example of fidelity to seasonal habitat in the absence of any contemporary barriers.
19					2016	Expression pattern of heat shock proteins during acute thermal stress in the Antarctic sea urchin, Sterechinus neumayeri	González, K., Gaitán-Espitia, J., Font A., Cárdenas, C., & González-Aravena, M.	HSP, Thermal tolerance, Chaperones, Ocean warming, Sea urchin	Antarctic marine organisms have evolved a variety of physiological, life-history and molecular adaptations that allow them to cope with the extreme conditions in one of the coldest and most temperature-stable marine environments on Earth. The increase in temperature of the Southern Ocean, product of climate change, represents a great challenge for the survival of these organisms. It has been documented that some Antarctic marine invertebrates are not capable of generating a thermal stress response by means of an increase in the synthesis of heat shock proteins, which could be related with their low capacity for acclimatization. In order to understand the role of heat shock proteins as a compensatory response in Antarctic marine species to projected scenarios of increased seawater temperatures, we assessed the expression of the genes Hsp90, Grp78, Hyou1 and Hsc70 in the Antarctic sea urchin Sterechinus neumayeri under three thermal treatments (1 °C, 3 °C and 5 °C), for a period of exposure of 1, 24 and 48 h.
20					2016	The Antarctic Circumpolar Current as a diversification trigger for deep-sea octocorals	Dueñas, L.F., Tracey, D.M., Crawford, A.J., Wilke, T., Alderslade, P., & Sánchez, J.A.	Antarctic Circumpolar Current, Gene flow, Primnoid octocorals, Southern Ocean, Deep-sea, Statistical phylogeography	Background: Antarctica is surrounded by the Antarctic Circumpolar Current (ACC), the largest and strongest current in the world. Despite its potential importance for shaping biogeographical patterns, the distribution and connectivity of deep-sea populations across the ACC remain poorly understood. In this study we conducted the first assessment of phylogeographical patterns in deep-sea octocorals in the South Pacific and Southern Ocean, specifically a group of closely related bottlebrush octocorals (Primnoidae: Tokoprymno and Thourella), as a test case to study the effect of the ACC on the population structure of brooding species. We assessed the degree to which the ACC constitutes a barrier to gene flow between northern and southern populations and whether the onset of diversification of these corals coincides with the origin of the ACC (Oligocene-Miocene boundary). Results: Based on DNA sequences of two nuclear genes from 80 individuals and a combination of phylogeographic model-testing approaches we found a phylogenetic break corresponding to the spatial occurrence of the ACC. We also found significant genetic structure among our four regional populations. However, we uncovered shared haplotypes among certain population pairs, suggesting long-distance, asymmetrical migration. Our divergence time analyses indicated that the separation of amphi-ACC populations took place during the Middle Miocene around 12.6 million years ago, i.e., after the formation of the ACC. Conclusion: We suggest that the ACC constitutes a semi-permeable barrier to these deep-sea octocorals capable of separating and structuring populations, while allowing short periods of gene flow. The fluctuations in latitudinal positioning of the ACC during the Miocene likely contributed to the diversification of these octocorals. Additionally, we provide evidence that the populations from each of our four sampling regions could actually constitute different species.
21					2016	Phylogenomics and historical biogeography of the monocot order Liliales: out of Australia and through Antarctica	Givnish, T.J., Zuluaga, A., Marques, I., Lam, V.K.Y., Gomez, M.S., Iles, W.J.D., Ames, M., Spalink, D., Moeller, J.R., Briggs, B.G., Lyon, S.P., Stevenson, D.W., Zomlefer, W., Graham, S.W.		We present the first phylogenomic analysis of relationships among all ten families of Liliales, based on 75 plastid genes from 35 species in 29 genera, and 97 additional plastomes stratified across angiosperm lineages. We used a supermatrix approach to extend our analysis to 58 of 64 genera of Liliales and calibrated the resulting phylogeny against 17 fossil dates to produce a new timeline for monocot evolution. Liliales diverged from other monocots 124 Mya and began splitting into separate families 113 Mya. Our data support an Australian origin for Liliales, with close relationships between three pairs of lineages (Corsiaceae/Campynemataceae, Philesiaceae/Ripogonaceae, tribes Alstroemerieae/Luzuriageae) in South America and Australia or New Zealand reflecting teleconnections of these areas via Antarctica. Long-distance dispersal (LDD) across the Pacific and Tasman Sea led to re-invasion of New Zealand by two lineages (Luzuriaga, Ripogonum); LDD allowed Campynemanthe to colonize New Caledonia after its submergence until 37 Mya. LDD permitted Colchicaceae to invade East Asia and Africa from Australia, and re-invade Africa from Australia. Periodic desert greening permitted Gloriosa and Iphigenia to colonize Southeast Asia overland from Africa, and Androcymbium–Colchicum to invade the Mediterranean from South Africa. Melanthiaceae and Liliaceae crossed the Bering land-bridge several times from the Miocene to the Pleistocene.
22					2016	Orchid historical biogeography, diversification, Antarctica and the paradox of orchid dispersal	Givnish, T.J., Spalink, D., Ames, M., Lyon, S.P., Hunter, S.J., Zuluaga, A., Doucette, A., Caro, G.G., McDaniel, J., Clements, M.A., Arroyo, M.T.K., Endara, L., Kriebel, R., Williams, N.H., Cameron, K.M.	Asparagales, Bi SSE, BioGeo BEARS, long-distance dispersal, Neotropics, Southeast Asia	Aim: Orchidaceae is the most species-rich angiosperm family and has one of the broadest distributions. Until now, the lack of a well-resolved phylogeny has prevented analyses of orchid historical biogeography. In this study, we use such a phylogeny to estimate the geographical spread of orchids, evaluate the importance of different regions in their diversification and assess the role of long-distance dispersal (LDD) in generating orchid diversity. Location: Global. Methods: Analyses use a phylogeny including species representing all five orchid subfamilies and almost all tribes and subtribes, calibrated against 17 angiosperm fossils. We estimated historical biogeography and assessed the importance of different regions for rates of speciation, extinction and net species diversification. We evaluated the impact of particular LDD events on orchid diversity by asking how many species evolved in the new range subsequent to those events. Results: Orchids appear to have arisen in Australia 112 Ma (95% higher probability distribution: 102.0–120.0 Ma), then spread to the Neotropics via Antarctica by 90 Ma (HPD: 79.7–99.5 Ma), when all three continents were in close contact and apostasioids split from the ancestor of all other orchids. Ancestors of vanilloids, cypripedioids and orchidoids+epidendroids appear to have originated in the Neotropics 84–64 Ma. Repeated long- and short-distance dispersal occurred through orchid history: stochastic mapping identified a mean total of 74 LDD events or 0.8 Ma−1. Across orchid history, Southeast Asia was the most important source and maximally accelerated net diversification; across epidendroids, the Neotropics maximally accelerated diversification. Main conclusions: Our analysis provides the first biogeographical history of the orchids, implicating Australia, the Neotropics and Antarctica in their origin. LDD and life in the Neotropics – especially the Andes – had profound effects on their spread and diversification; > 97% of all orchid species are restricted to individual continents.
23					2017	Efectos del ejercicio aeróbico en la composición corporal, resistencia cardiovascular, ciclo circadiano, síndrome T3 Polar en la primera misión de Colombia a la Antártida	Castro-Herrera, J.	Composición corporal, ejercicio, temperaturas extremas.	En el verano austral 2014-2015 se desarrolló la Primera Expedición de Colombia a la Antártida. Con el propósito de ser país consultivo en el Sistema del Tratado Antártico, la Fuerza Aérea Colombiana se vinculó con un proyecto en ciencias de la salud que pretendía determinar los cambios fisiológicos cardiorrespiratorios, la composición corporal, el síndrome T3 Polar y la calidad del sueño, que se presentan en la aclimatación aguda al frío extremo, en un grupo de expedicionarios de la Antártida, con ejercicio aeróbico durante cuatro semanas de entrenamiento. Se valoraron, en Colombia y en la Antártida, 36 sujetos que aleatoriamente se dividieron en dos grupos; uno realizó ejercicio y otro se mantuvo sedentario. A los participantes se les aplico el índice clínico de Zulewsky, la escala de Epworth, el cuestionario de Pittsburg, consumo máximo de oxígeno y composición corporal. De los 36 sujetos, el 80% son hombres y solo el 20% son mujeres, todos en un promedio de edad de 33.5 años. Los que realizaron ejercicio disminuyeron 4% el IMC, disminuyeron 30% la probabilidad de padecer hipotiroidismo, el 48% mejoraron la calidad de sueño, el 51% disminuyeron la probabilidad de somnolencia diurna y aumentaron el 7% el consumo máximo de oxígeno. El grupo control de sedentarios aumentó 10 % de grasa y disminuyó 10 % su condición cardiovascular. Lo anterior muestra que el ejercicio es un mecanismo protector en la exposición a temperaturas extremas y disminuye la probabilidad de desarrollar patologías metabólicas y cardiovasculares. El sedentarismo, más el frío extremo, deteriora rápidamente las funciones, dando lugar a enfermedades de cualquier tipo.
24					2017	Colombia En El Continente Blanco [Colombia in the White Continent]	Espinel-Bermúdez, J.	Antártida, vinculación, miembro consultivo y política	Se pretende mostrar la importancia que tiene la Antártica para Colombia. En principio, se evidencia la repercusión geoestratégica, científica y económica de este continente, así como la conexión existente entre este lugar y el resto del Planeta; con base en ello es preciso dar conocer la trascendencia del Sistema de Tratado Antártico y el estatus de vinculación de Colombia a esta organización. El alcance que ha tenido la Política Nacional de los Océanos (en adelante PNOEC) para el país al crear y mantener el Programa Antártico Colombiano es relevante y cuyo objetivo primario es llegar a ser miembro consultivo del Tratado, siendo necesario a la vez considerar el papel que juega la Armada Nacional en la PNOEC y la invaluable oportunidad que brinda el Continente Blanco en beneficio de la Nación.
25					2017	COLOMBIA Y ANTÁRTICA: Enlazadas por el mar y su biodiversidad	Fonseca González, I., & Londoño-Mesa, M.
26					2017	“Todo listo para volver a la Antártida” [Everything Ready to Return to Antarctica]	Correa-Escobar, M.
27					2017	Mercury concentrations in wild humpback whales (Megaptera novaeangliae) sampled in the Colombian Pacific and in Antarctic Peninsula	Angel-Romero, P., Barragán-Barrera, D., Botero-Acosta, N., Riet-Sapriza, F., Caballero, S., & Luna-Acosta, A.	“Total	Mercury, Humpback
28					2017	Revisiting the andean tropical glacier behavior during the Antarctic cold reversal	Jomelli, V,., Martin, L., Blard, P.H., Favier, V., Vuillé, M., & Ceballos, J.L.	Tropical glaciers, ACR, Younger Dryas, Cosmogenic nuclides	The sensitivity of tropical glaciers to paleoclimatic conditions that prevailed during the Antarctic cold reversal (ACR, ca. 14.5-12.9 ka) has been the subject of a wide debate. In 2014 a paper suggested that tropical glaciers responded very sensitively to the changing climate during the ACR (Jomelli et al., 2014). In this study, we reexamine the conclusions from this study by recalculating previous chronologies based on 226 10Be and 14 3He ages respectively, and using the most up-to date production rates for these cosmogenic nuclides in the Tropical Andes. 53 moraines from 25 glaciers were selected from the previous analysis provided by Jomelli et al. (2014) located in Colombia, Peru and Bolivia. We then focused on two distinct calculations. First we considered the oldest moraine and its uncertainty for every glacier representing the preserved evidence of the maximum glacier extents during the last deglaciation period, and binned the results into 5 distinct periods encompassing the Antarctic cold reversal and Younger Dryas (YD) chronozones: pre-ACR, ACR, ACR-YD, YD and post-YD respectively. Results revealed a predominance of pre-ACR and ACR ages, accounting for 60% of the glaciers. Second we counted the number of moraines per glacier according to the different groups. 21 moraines (40%) of the selected glaciers belong to the pre-ACR-ACR chronozones while 3 moraines only (5%) were dated to the YD and YD-Holocene groups. The rest was assigned to the ACR-YD. These results suggest that moraine records are a very good proxy to document the ACR signal in the Tropical Andes.
29					2017	Climate change effects on Antarctic benthos: a spatially explicit model approach	Torre L., Tabares P.C.C., Momo F., Meyer J.F.C.A., Sahade R.	Bioinformatics, Climate models, EcosystemsIce, MATLAB, Sedimentation, Sediments	Resumen: The Antarctic Peninsula is one of the regions on the Earth with the clearest evidence of recent and fast air warming. This air temperature rise has caused massive glacier retreat leading to an increased influx of glacier meltwater which entails hydrological changes in coastal waters, increasing sediment input and ice-scouring impact regime. It has been hypothesized that an increase of sediment load due to glacier retreat resulted in a remarkable benthic community shift in Potter Cove, a small inlet of the South Shetland Islands. In order to test this hypothesis, we developed an explicit spatial model to explore the link between sedimentation and ice-scouring increase upon four of the most conspicuous benthic species. This is a valuable novel approach since disturbances are strongly dependent of the space. The model takes into account sediment and population dynamics with Lotka-Volterra competition, a sediment-dependent mortality term and a randomized ice-scouring biomass removal. With the developed algorithm, and using a MATLAB environment, numerical simulations for scenarios with different sedimentation and ice-impact rates were undertaken in order to evaluate the effect of this phenomenon on biological dynamics. Comparing simulation results with biological data, the model not only recreates the spatial community distribution pattern but also seems to be able to recreate the shifts in abundance under sedimentation enhancement, pointing out its importance as a structuring factor of polar benthic communities. Considering the challenges of Antarctic field work, this model represents a powerful tool for assessing, understanding, and predicting the effects of climate change on threatened Antarctic coastal ecosystems.
30					2017	Genetic differentiation between humpback whales (Megaptera novaeangliae) from Atlantic and Pacific breeding grounds of South America	Cypriano-Souza, A.L., Engel, M.H., Caballero, Susana., Olavarría, C., Flórez-González, Lilian., Capella, J., Steel, D., Sremba, A., Aguayo, A., Thiele, D., Baker, C.S., & Bonatto, S.L.	Individual assignment, Megapteranovaeangliae, microsatellites, migration, mtDNA, population, genetic structure.	Humpback whales wintering in tropical waters along the Atlantic and Pacific coasts of the South American continent are thought to represent distinct populations or “stocks.” Here we present the first analysis of genetic differentiation and estimates of gene flow between these breeding stocks, based on both mitochondrial DNA (mtDNA) control region sequences (465 bp) and 16 microsatellite loci from samples collected off Brazil (n = 277) and Colombia (n = 148), as well as feeding areas near the western Antarctic Peninsula (n = 86). We found significant differentiation between Brazilian and Colombian breeding grounds at both mtDNA (FST = 0.058) and microsatellite (FST = 0.011) markers and corroborated previous studies showing genetic similarity between humpbacks from Colombia and those from Antarctic Peninsula feeding areas. Estimates of long-term gene flow between Brazil and Colombia were low to moderate, asymmetrical, and mostly mediated by males. Assignment procedures detected some cases of interchange and individuals of admixed ancestry between breeding grounds, indicating limited mixing of individuals between these stocks. Overall, results highlight the differentiation of humpback whale breeding populations with adjacent feeding grounds. This appears to be a remarkable example of fidelity to seasonal habitat in the absence of any contemporary barriers.
31					2017	Tendencias del nivel medio del mar en el litoral del Pacífico Sur Oriental	Manuel Contreras Lopez, Jimmy Cevallos y Ricardo Torres	Colombia,Ecuador Peru, Chile	Twenty-three long records were gathered from tidal stations based within the Colombian Pacific basin (2 stations), Ecuador (5), Peru (1) and Chile (15). Twenty-one records cover over 30 years, representing the effect of contemporary climate change. A linear trend is fitted to all series by the least squares method. The slope of these lines is interpreted as the rate of sea level change at each location. The resulting rates are not homogenous, varying from negative (-4.0 mm/year) to positive (+5.7 mm/year). The positive rates are interpreted as approximations to a rise in mean sea level produced by climate change, while the negative rates were interpreted as the effect of tectonic processes occurring in interseismic periods. In this way, in those locations where negative sea-level change rates are found, the fixed land reference is rising faster than sea level.
32					2018	An initial approximation to the meteo-marine conditions of south bay (Doumer island) and comparison of the meteorological behavior between Doumer and Anvers islands, Antarctica (austral summer 2016-2017)	Villegas, N., Málikov, I., & Cárdenas, C.	Western Antarctic Peninsula, Palmer Archipelago, meteorology, seawater temperature	In order to contribute to the meteo-marine knowledge of the Western Antarctic Peninsula (WAP), the behavior of some atmospheric characteristics of South Bay is described and meteorological differences were identified in two islands of the Palmer Archipelago (south of the Gerlache Strait). The data was obtained during the III Colombian Antarctic Expedition in the Austral summer 2016-2017. The series of air temperature, relative humidity, dew point temperature, wind direction and wind speed at Doumer Island were compared with those recorded at Anvers Island and with sea temperature behavior at 10 m depth in South Bay (Doumer Island). It was concluded that although Anvers and Doumer Islands are neighboring, the behavior of meteo-marine variables in the Austral summer 2016-2017 differs.
33					2018	Hielo. Bitácora de una expedicionaria antártica	Posada-Swafford, A.		Desde hace casi quince años una de las principales periodistas científicas colombianas ha realizado expediciones a la Antártida, el enorme continente de hielo que ha sido uno de los territorios más enigmáticos de la geografía del mundo, y que alberga al Polo Sur. Explorado por grandes aventureros como Roald Amundsen y Robert Scott, quienes protagonizaron un reto de dimensiones épicas para ver cuál de los dos llegaba primero al punto más central de una de las antípodas, este territorio es aún una gran incógnita que fascina a científicos y a viajeros. Posada-Swaἀord, con la paciencia de quien recolecta historias y anécdotas, datos útiles y leyendas, centenas de apuntes y objetos (piedras, plumas de pingüino, insignias de expediciones, etcétera), construyó una bitácora única en la que quedan consignadas sus reflexiones sobre el país del hielo que amenaza con desaparecer por el calentamiento global.
34					2018	An overview of Colombia’s Antarctic programme	Sanchez, W.A.	Colombia, navy, Antarctica, Latin America, 20 de Julio	This paper provides an overview of the history and growth of Colombia’s Antarctic programme and how it has rapidly progressed in recent years. The country carried out its first Antarctic expedition with a domestically manufactured vessel during the 2014–2015 austral summer. Annual expeditions have continued since then, and in early 2018 the government announced its intention to acquire a new vessel and establish a seasonal base by 2025 at the latest in a location yet to be determined. This rapid succession of achievements demonstrates Colombia’s seriousness about its Antarctic programme. Nevertheless, a major challenge will be to secure funding for its Antarctic programme, thus 2018 will be a critical year as the country will hold general elections, and it will be imperative for the next administration to consider the programme a priority in order to maintain its momentum. It is important to understand the intention and objectives of non-claimant nations with growing Antarctic programmes and for the international community to harness this interest so that they can carry out meaningful contributions in order to protect Antarctica.
35					2018	Detenerse a respirar en el fin del mundo: Colombia en Antártida	López, N.	Arte, Antártida, conservación, programa antártico colombiano.	El Proyecto Colombiano de Arte en Antártida (PCAA) acerca la Antártida, su importancia y sus problemáticas, a un público general. La meta es consolidar un programa artístico y cultural que haga visible, a nivel nacional e internacional, la participación de Colombia en las misiones que se llevan a cabo en el continente blanco, mientras crea conciencia sobre el inmenso valor que este representa para la vida en el planeta. Se aspira a que en 2035 el pcaa se haya institucionalizado dentro del circuitoartístico de Colombia. En ensayo fotográfico hace un recorrido por intervenciones sutiles: recolectar agua de los hielos que se descongelan, tomar el pulso del corazón antártico, atrapar aire frío y luego repartirlo por el mundo.
36					2018	Tardígrados (Tardigrada: Panarthropoda) de Bahía Fildes en la Isla Rey Jorge, Península Antártica	Marín-Muñoz, G., & Londoño-Mesa, M.
37					2018	Zooplancton gelatinoso (Cnidaria, Tunicata) del Pacífico Oriental Tropical y la Península Antártica	RestrepO, L., Quan-Young, L., & Londoño-Mesa, M.
38					2018	First record of Juncaceicola as endophytic fungi associated with Deschampsia antarctica Desv.	Andrade, G.A.K., Cañón, E.R.P., Alves, R.P., Schmitz, D., Schünemann, A.L., de Albuquerque, M.P., Putzke, J., Pereira, A.B., Victoria, F.C.	Antarctic, Fungi Isolation, Mycodiversity, Phylogeny Taxonomy	In the current study, we present the molecular characterization of an endophyte fungus associated with the leaves of Deschampsia antarctica Desv. (Poaceae), a monocot species native to Antarctica. The isolate was obtained from 90 leaf fragments from two distinct collection sites, both located on Half Moon Island, South Shetland Islands and Maritime Antarctica. The internal transcribed spacer region (ITS) was sequenced and the endophytic fungus was identified as belonging to the genus Juncaceicola Tennakoon, Camporesi, Phook and K.D. Hyde (99% nucleotide sequence identity). When compared to all fungi of the genus Juncaceicola deposited in data base, our isolate showed greater proximity with Juncaceicola typharum, however, because it presents a low bootstrap value to be considered a new species, we treat it as Juncaceicola cf. typharum. Moreover, the identification of our isolate as belonging to the genus Juncaceicola makes this the first occurrence of a species of this genus to be associated with the leaves of Antarctic plants. This work is considered as a starting point for other studies with fungi of this genus associated with leaves of Deschampsia antarctica, as it presents results from two collection points on a single Antarctic island, suggesting that new sites and new Antarctic islands should be explored.
39					2018	Geographic and temporal patterns of non-lethal attacks on humpback whales by killer whales in the eastern South Pacific and the Antarctic Peninsula	Capella, J.J., Félix, F., Flórez-González, Lilian., Gibbons, J., Haase, B., Guzman, H.M.	Eastern South Pacific, Humpback whale, Killer whale, Megaptera novaeangliae, Migration, Non-lethal attacks, Orcinus orca, Rake scars	The role and impact of killer whales Orcinus orca as predators of baleen whales has been emphasized by studies of humpback whales Megaptera novaeangliae. In this study, rake marks on the fluke were used as a proxy for predatory attacks in a sample of 2909 adult humpback whales and 133 calves from 5 breeding and 2 feeding locations in the eastern South Pacific and the Antarctic Peninsula. The goal of this study was to evaluate how often, at what age, where, and when humpback whales were more susceptible to attacks. Overall, 11.5% of adults and 19.5% of calves had rake marks on their flukes. Significant differences were found in the prevalence of scars in calves when comparing breeding (9%) vs. feeding areas (34%) (Χ 2 = 10.23, p < 0.01). Multi-year sighting analysis of scar acquisition in 120 adults (82% site fidelity) and 37 calves in the Magellan Strait showed no new marks after the initial sighting for the subsequent 15 yr. This finding indicates that rake marks were most probably acquired when whales were calves, which supports the belief that scar acquisition is a once in a lifetime event. The odds of having rake marks increased with time but with a significantly higher rate in calves (Χ 2 = 5.04, p < 0.05), which suggests an increase in predation pressure over time. Our results support the earlier hypothesis that killer whale attacks occur mostly on calves, near breeding sites, and during the first migration to feeding areas.
40					2018	Distribucion Espacial de la Varibale densidad de los estrechos de Gerlache y Bransfield durante el verano austral entre 1979-2019.	Torres Ramirez F. J	Tratado Antartico, Gerlache, Bransfield, Densidad, Control de Calidad, Verano Austral	Colombia ha realizado expediciones a la Antártica desde el año 2014, con el objetivo de contribuir al conocimiento sobre el continente blanco y materializar los intereses nacionales sobre el mismo. El presente estudio aporta al entendimiento de la dinámica oceanográfica en los estrechos de Gerlache y Bransfield a partir del análisis conjunto de información de temperatura, salinidad y presión recolectada con equipos CTD durante las expediciones antárticas realizadas por Colombia entre los años 2014 y 2019, complementada con información de 40 años obtenida del World Ocean Database. Este análisis permitió a través de un control de calidad previo, calcular y graficar la distribución horizontal de la variable densidad a diferentes profundidades estándar durante el verano austral entre 1979 a 2019, para así entender la distribución de la variable mencionada en el área de estudio. Se analizó el comportamiento de la densidad, demostrando a través de los resultados que, este parámetro se da en razón a las variaciones de la salinidad y no de la temperatura como ocurre en latitudes bajas. A diferencia de estudios previos realizados en la península Antártica para un año particular, en la presente investigación se seleccionó un periodo de 40 años del verano austral (meses de enero, febrero y marzo), con miras a conocer la distribución horizontal de la variable densidad para diferentes profundidades estándar y a determinar las condiciones esperadas, las cuales son un indicador de comportamiento a nivel general en el área de estudio.
41					2019	Effects of an Explosive Polar Cyclone Crossing the Antarctic Marginal Ice Zone	Vichi, M., Eayrs, C., Alberello, A., Bekker, A., Bennetts, L., Holland, D., de Jong, E., Joubert, W., MacHutchon, K., Messori, G, Mojica, J., Onorato, M., Saunders, C., Skatulla, S., & Toffoli, A.		Antarctic sea ice shows a large degree of regional variability, which is partly driven by severe weather events. Here we bring a new perspective on synoptic sea ice changes by presenting the first in situ observations of an explosive extratropical cyclone crossing the winter Antarctic marginal ice zone (MIZ) in the South Atlantic. This is complemented by the analysis of subsequent cyclones and highlights the rapid variations that ice-landing cyclones cause on sea ice: Midlatitude warm oceanic air is advected onto the ice, and storm waves generated close to the ice edge contribute to the maintenance of an unconsolidated surface through which waves propagate far into the ice. MIZ features may thus extend further poleward in the Southern Ocean than currently estimated. A concentration-based MIZ definition is inadequate, since it fails to describe a sea ice configuration which is deeply rearranged by synoptic weather.
42					2019	How are we getting there? The present and future of South America’s Antarctic fleet	Sanchez, W.A.	Polar Vessels, Shipyards, Peru, Chile, Argentina, Brazil, Icebreaker	While South America is geographically close to Antarctica, more so than some countries that claim Antarctic territory, it is nevertheless important to maintain modern and operational platforms, particularly vessels, via which South American states can travel to this region. In recent years, Peru has obtained a new polar vessel, while Chile is domestically manufacturing a new icebreaker and Brazil is looking to purchase a new polar ship. Nevertheless, countries like Argentina and Uruguay, due to limited funds, do not appear to have plans to acquire new polar vessels to replace their current, ageing naval platforms. Certainly, governments can also utilise aircraft to transport personnel and equipment to Antarctica as well as to carry out some scientific tests and search-and-rescue operations. However there are particular advantages to possessing a vessel in the inventory of any country’s Antarctic program, since it can transport heavy equipment, and perform subsurface tests out at sea. Polar vessels also carry smaller craft and a helicopter, which multiplies the ship’s capabilities. This essay aims to discuss the current operational status of South America’s polar platforms, with a specific focus on ships, and what are their future. We will analyse the region’s ships and compare them to other nations that have Antarctic programmes (e.g. Australia, the People’s Republic of China and the United States), in order to have an idea of how South American states are doing in comparison to other programs. As we look at South America’s present and attempt to predict the region’s future in Antarctica, we will discuss issues like cooperation amongst South American Antarctic programs, and the future of regionally manufactured naval platforms for polar use.
43					2019	Water cherenkov detector optimization for space weather studies in antarctic	Otiniano L.; Peña J.; Vega J.; Valera V.B.; Castromonte C.	Cerenkov counters, Cosmic rays, Data handling, Electromagnetic shielding, Geomagnetism, Particle detectors	During the last two Peruvian summer campaigns in the Antarctica (2018 and 2019), two separate prototype water Cherenkov detectors of the LAGO project have been tested. As at high latitudes the lower geomagnetic shielding allows for the observation of cosmic rays lower than those at middle latitudes, the installation of a detector in the Antarctica is important for the development of the LAGO space weather program. The objectives fulfilled in the second summer campaign were: a general improvement of the design of the detectors, wi-fi data transmission, autonomous operation, the elimination of light leaking and the optimization of the geometry for better separation of the electromagnetic / muonic components measured in the detector. A comparison between the data obtained in the two Antarctic campaigns is shown, making emphasis in the measured flows and the strategy of using a second trigger level in the acquisition stage in order to perform a pre-processing of the data. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).
44					2019	Zooplankton composition and taxonomic abundance from South Pacific until Antarctic Peninsula 2016-2017	López L.H.M.; Franco-Herrera Andres.	Antarctica, Connectivity, South Pacific, Zooplankton	With the purpose of contributing to the knowledge of the zooplankton associated with the water masses present along a latitudinal gradient from Peru to the Antarctic Peninsula, 14 samples were obtained, with a conical net of 250 μm mesh size and 60 cm of mouth diameter, towed from 0 to 200 m water depth, within the III Scientific Expedition of Colombia to Antarctica “Almirante Padilla” (Austral Summer 2016-2017). The results allowed to determine a total of 75 family/morphotypes (f/m), belonging to 32 orders. The orders Calanoida (20%) and Perciformes (12%) predominated in this study. Fish eggs and larvae, in addition to bivalves, and cypris, salps and other gelatinous organisms contributed with 54% of importance. In relation to density, the families of the subclass Copepoda, Calanidae, Paracalanidae, Clausocalanidae, Oncaeidae and Eucalanidae were the most representative. Calanidae family showed the highest density across the latitudinal gradient, with values between 1594 ind • 100 m-3 and 6057 ind • 100 m-3. The highest densities of zooplankton were for the South Pacific, where differences were found with respect to the densities in the Antarctic stations (Mood: 1.4 p-value: 0.24 α: 0.05 and 95% confidence). However, the cluster analysis showed an association between stations in relation to abundance of zooplankton in this study and found a Pearson correlation of 0.95 with this it can be concluded that if there is a ecological connectivity between the mesozooplankton community along the South Pacific, which is attributed to the system of currents that plays an important role in the distribution of this community, as well as events of deep water upwellings that allow to find cosmopolitan families. © 2019 INVEMAR. All rights reserved.
45					2019	Mesozooplankton biomass and epipelagic copepod assemblages in the Gerlache Strait (Antarctica) during the 2015 austral summer	Giraldo A.; Críales-Hernández M.I.; Jeréz-Guerrero M.; Mojica-Moncada Diego	Aetideus armatus, Antarctic Peninsula, Bellingshausen Sea, Oithona similis, Zooplankton	Mesozooplankton biomass and epipelagic copepod assemblage composition and distribution were studied in the Gerlache Strait from January 17 to 22, 2015, as part of the first Colombian oceanographic expedition to the Antarctic. Mesozooplankton-integrated biomass was generally low (< 5 mgdry weight/m−2) in the outer area of the northern section of the Gerlache Strait (between Crocker Passage and Hughes Bay) although there was a notable increase southward, with the highest value (1.02 g dry weight / m−2) at the entrance of Wilhelmina Bay in the central zone of the Strait. The epipelagic copepod assemblage comprised 17 species belonging to 4 orders and 13 families. The dominant species by number was Oithona similis, followed by O. frigida, Ctenocalanus citer, Drescheriella glacialis, and Calanoides acutus. Aetideus armatus is reported for the first time in the western sector of the Antarctic Peninsula. Differences in the assemblages of copepods between the northern and southern section of the Gerlache Strait were established. Considering the previous results reported about hydrography and phytoplankton composition in Gerlache Strait and our analysis of the copepod assemblage structure, a scenario is suggested in which, at less during January 2015, each section of the Strait exhibited a particular copepod assemblage structure: a northern section was dominated by small-sized copepods while the southern section was dominated by small-sized and large-sized copepods.
46					2020	Hydrographic conditions during two austral summer situations (2015 and 2017) in the Gerlache and Bismarck straits, northern Antarctic Peninsula	Rafael Ricardo Torres Parra a, Ana Lucía Caicedo Laurido b, José David Iriarte Sánchez b	Antarctic peninsula; OMP analysis; θ-S diagram; Water masses	Hydrography in the Gerlache and Bismarck straits is described based on data collected in Januaries of 2015 and 2017, during austral summer. These straits are in the northern Antarctic Peninsula (NAP) continental shelf. In the study area, temperature in the surface mixed layer during January 2017 was warmer than recorded in other years, contemporaneous with an extreme decrease in Antarctic sea ice extent at the end of 2016. This was probably caused by warm water advected from the north into Gerlache Strait, a consequence of northeasterly surface winds over the NAP, forced by a Southern Annular Mode (SAM) negative phase. Optimum multiparameter analysis indicated that relatively warm, salty and low-oxygenated modified Circumpolar Deep Water (mCDW) intrudes over the NAP continental shelf and dominates the Bismarck Strait, where it enters the Gerlache Strait, especially through its southern extremity. The mCDW mixes with relatively cold, fresh and recently ventilated modified High Salinity Shelf Water (mHSSW), producing temporal variations in water proportions. HSSW forms in the Weddell Sea and is advected southward along the deep basins of the Bransfield Strait, entering as bottom water into Gerlache Strait via its northern limit. There were two fronts in Gerlache Strait during both summers. First was a surface thermal front in the mixed layer represented by the 1 °C isotherm (~64.5°S), which separated colder waters toward Bismarck Strait. Second was a sub-pycnocline front, represented by the 0.4 °C and 220 μmol kg−1 dissolved oxygen contours below ~100 dbar, which separated mCDW toward Bismarck Strait from mHSSW on the northern side of the strait. This frontal position varies as a consequence of temporal variations in source water fractions. Moreover, changes in Ekman transport, forced by enhanced westerly winds associated with a SAM positive phase, appeared responsible for a major fraction of mCDW in Gerlache Strait during 2015 relative to 2017. The spatiotemporal variability of source water mixing in the water column structure of the Gerlache Strait might have implications for local biological and chemical cycles, and for regional climate feedbacks, because warm mCDW accelerates glacier retreat in the western Antarctic Peninsula.
47					2020	Beach litter distribution in Admiralty Bay, King George Island, Antarctica	Anfuso, G., Bolívar-Anillo, H., Asensio-Montesinos, F., Portantiolo Manzolli, R., Portz, L., & Villate Daza, D.	Wood fragments, Plastic items, Foam, Raman spectroscopy	In the Antarctic Peninsula, most important activities are touristic visits, from the second half of the 20th Century, and scientific investigation linked to 75 research stations. Beach litter content/abundance was investigated at 17 beaches in Admiralty Bay (King George Island, Antarctica) and the type of plastic material was determined by Raman spectroscopy. An average value of 0.16 items m−1 was observed. Wood items consisted of processed wood fragments representing 47.27% of the total. Foam represented 21%, hard plastic pieces 9.68% (consisting of polyvinyl chloride or high density polyethylene), metal 3.37%, rubber fragments 2.81%, foamed plastic pieces 2.66% (composed by polystyrene), the rest of categories representing less than 2% of the total. Wood debris and metal are essentially remnant objects of ancient whaling activities and research expeditions, polyurethane and expanded polystyrene materials have different origins and hard plastic, rubber, paper/cardboard and paint fragments seem mostly linked to present research activities.
48					2020	Colombia in the Antarctica: Approaches to a scientific/social investigation. A call to the academy/state/society	Lopera-Ramírez, L.	Antártida, proyecto de país, enfoque diferencial	La Antártida, para muchos desconocida, para otros épica, y para las grandes potencias del globo un lugar de posicionamiento geoestratégico sin precedentes, merece la atención no solo del andamiaje estatal como tal, sino de una triada donde a este se anejan la academia y la sociedad desde su expresión visionaria/participativa que permite entregar el valor necesario a un “proyecto país” con enfoque diferencial, direccionado a los intereses nacionales, desde el entendido que estos trascienden más allá de las fronteras, donde las relaciones internacionales y la política exterior de un estado permiten la gestión. Con el fin de adentrarnos en el objeto de estudio, es preciso contextualizar algunos aspectos que permitirán un recorrido entre la relevancia y la fastuosa historia del Continente Blanco. En principio, se hará referencia a la importancia estratégica, sus características y lo que sígnica para el hemisferio en conjunto con el majestuoso Océano Antártico que lo rodea.
49					2020	Diversity and Functioning of Antarctic Seaweed Microbiomes	Gaitán-Espitia, J., & Schmid, M.		Antarctic macroalgae are important primary producers and habitat-forming species that play fundamental roles in Antarctic coastal habitats and sustain important communities of benthic organisms, including a not well-known microbiota. Anthropogenic pressures, e.g., increasing ocean temperatures and extreme events, have threatened the ecological integrity of several seaweed species and also can modify the range shifts (e.g., introduction of Durvillaea antarctica in King George Island), cause local extinctions, and alter the structure of these associations in their natural habitats. However, understanding and prediction of the responses of seaweeds to changing environment and rapid anthropogenic-driven change cannot be done without considering the associated microbiome. These complex microbial communities are intricately involved in the host health, defense, growth, and development of seaweeds, thus with far-reaching implications for the ecology of the whole coastal ecosystem. For most Antarctic seaweeds, the microbiome comprises a stable core as well as microbes whose presence depends on local conditions and transient microbial associates that are responsive to biotic and abiotic processes across spatial and temporal scales. In this chapter, we will explore the ecological and genetic diversity of microbiomes in Antarctic seaweeds and their functional connections.
50					2020	Estructura y distribución de la comunidad microfitoplanctónica a lo largo del estrecho de Gerlache durante el verano austral 2018-2019	De La Hoz Barrientos, L., Cañón Páez, M., & Sánchez, D.	microfitoplancton, estructura, Antártica, estrecho de Gerlache	En el presente estudio se describe la estructura de la comunidad fitoplanctónica y su distribución en el estrecho de Gerlache durante el verano austral 2018-2019. Se realizaron arrastres verticales de 200 m a la superficie a través de una red bongo equipada con flujómetro. Las muestras se fijaron en lugol básico, en una relación 100:1. Muestras adicionales para el análisis de nutrientes y clorofila-a se tomaron a través de una roseta oceanográfica. Mediante un análisis de funciones empíricas ortogonales estandarizadas el estrecho de Gerlache fue regionalizado en cuatro regiones, usando los datos de riqueza y químicos. De las regiones identificadas se ubicaron dos en el norte, una en el centro y otra en el sur. En términos de riqueza se identificaron 40 taxones representados por 28 diatomeas, once dinoflagelados y un silicoflagelado. La mayor riqueza y abundancia se encontró en la región central, siendo las diatomeas el grupo dominante en todas las estaciones. Las especies Corethron criophilum y Porosira glacialis representaron el mayor aporte a la comunidad. Los dinoflagelados formaron el segundo grupo más distintivo en el área de estudio, representado por las especies Protoperidinium pyrum y Prorocentrum minimun. Por otra parte, los silicoflagelados con la especie Dictyocha sp. fueron el grupo con menor representatividad en el área; sin embargo, su mayor abundancia se observó en la región norte. Con base en investigaciones realizadas por otros autores en años anteriores para el mismo periodo climático se evidenciaron diferencias en la estructura de la comunidad, con dominancia de las diatomeas sobre los demás grupos identificados; dichos cambios pueden obedecer a las técnicas analíticas empleadas y a la variabilidad interanual.
51					2020	From Space to Earth: physical and biological impacts of glacier dynamics in the marine system by means of Remote Sensing at Almirantazgo Bay, Antarctica	Cárdenas, C., Casassa, G., Aguilar, X., Mojica, D., Johnson, E., & Brondi, F.	Antarctica, Radar tracking, Remote sensing, Spaceborne radar, Sea surface, Ocean temperature, MODIS	To determine the biological and physical mechanisms between Lange glacier and its pro-glacier marine system located in Almirantazgo bay, King George Island, Antarctica, specific variables were determined through remote sensing approaches shown in this work. These preliminary results will allow relating the dynamics of both systems, the glacier, and the marine ecosystem. The information for the estimation of surface flux velocity of the glacier was derived through Radar satellite images (Sentinel-1) by means of offset tracking, the bathymetry was derived from a Multi-beam Echo Sounder, and the Digital Elevation Modell was obtained by means of a Remotely Piloted Aircraft; Finally, the biological parameters were derived from MODIS and OLCI images for the analysis of satellite data to have a first insight to the characteristics of the marine system. This information will help to build the first frame needed to study through remote sensing approaches, the mechanisms that govern the interface among “Lang Glacier” and the “Almirantazgo Bay” at King George Island, Antarctica.
52					2020	Installing a prototype wind turbine to produce energy in Antarctica to allow a permanent Colombian scientific base to be established	Lozano-Jiménez, C.	Wind energy, renewable energy, Marambio Station, Seymour Island, Colombia Antarctic Program	This study was performed to support an expeditionary team of Colombian scientists seeking to promote and undertake research in various scientific fields in Antarctica. The work was part of the Colombian Antarctic program, which comprises various projects intended to lead to a permanent Colombian scientific base being established in the Antarctic. The first step involved installing a Colombian-made wind turbine to produce electricity at a permanent base. The aeolian turbine was designed to provide sufficient electricity to illuminate and heat a small base. The turbine was constructed using readily accessible materials but taking the Madrid Protocol environmental regulations into consideration. The project was performed at the Argentinian Antarctic Marambio Station on Seymour Island, off the Antarctic Peninsula. An initial field study performed in 2015 was the first of three phases of the project. In the initial phase, local meteorological data were gathered to support development of a prototype turbine and to allow a design to be selected that was robust enough for the extreme environmental conditions. The wind turbine was then constructed in Colombia. The second phase involved transporting the turbine to Antarctica and installing it at the Marambio Station in 2018. Finally, the physical conditions of structural and electronic components of the turbine were carefully inspected at the beginning of 2020 (after the turbine had operated continually for ~2 years) to allow repairs to be made and any necessary re-engineering to be performed.
53					2020	Projected shifts in the foraging habitat of crabeater seals along the Antarctic Peninsula	Hückstädt, L., Piñones, A., Palacios, D., McDonald, B., Dinniman, M., Hofmann, E., BurnsM J., Crocker, D., & Costa, D.		Crabeater seals exhibit extreme dietary specialization, feeding almost exclusively on Antarctic krill. This specialization has inextricably linked habitat use, life history and evolution of this pinniped species to the distribution of its prey. Therefore, the foraging habitat of crabeater seals can be used to infer the distribution of Antarctic krill. Here, we combined seal movements and diving behaviour with environmental variables to build a foraging habitat model for crabeater seals for the rapidly changing western Antarctic Peninsula (WAP). Our projections show that future crabeater seal foraging habitat and, by inference, krill distribution will expand towards offshore waters and the southern WAP in response to changes in circulation, water temperature and sea ice distribution. Antarctic krill biomass is projected to be negatively affected by the environmental changes, which are anticipated to manifest as a decrease in krill densities in coastal waters, with impacts on the land-/ice-based krill predator community, particularly in the northern WAP.
54					2020	Stereo-Photogrammetric Measurement Of Spatio-Temporal Velocity Fields At Lange Glacier, King George Island	Ellen Schwalbe, Robert Koschitzki, Erling Johnson, Diego Fernando Mojica Moncada, Benjamin Schröter, Carlos Cardenas, Gino Casassa & Hans-Gerd Maas	Cameras, Antarctica, Image sequences, Ice, Surface treatment, Radar tracking, Remote sensing	A network consisting of six cameras was set up on both sides of Lange Glacier on King George Island, Antarctica, for a period of two years to monitor changes in the glacier’s motion behaviour. The cameras were observing spatio-temporal glacier surface velocity vector fields as well as the position of the glacier front. Velocity field information was obtained from image sequences by applying subpixel accuracy photogrammetric image sequence analysis techniques. Georeferencing in a superordinate coordinate system was performed via integrated photogrammetric-geodetic network adjustment. As a result, velocity fields were determined with maximum glacier surface velocities in the order of 1.5 meter per day. The results of terrestrial camera image sequence processing can be used as validation and calibration reference for satellite image based glacier velocity dynamics calculations. Moreover, the very high temporal resolution of the image sequences taken at 20 minute time intervals can also be used to analyse highly dynamic processes.
55					2020	Latitudinal gradients of haemosporidian parasites: Prevalence, diversity and drivers of infection in the Thorn-tailed Rayadito (Aphrastura spinicauda)	Cuevas, E., Vianna, J.A., Botero-Delgadillo, E., Doussang, D., González-Acuña, D., Barroso, O., Rozzi, R., Vásquez, R.A., Quirici, V.	Haemoproteus, Haemosporidian parasites, Latitudinal gradient Leucocytozoon, Plasmodium, South American temperate forests	Latitudinal gradients are well-suited systems that may be helpful explaining distribution of haemosporidian parasites and host susceptibility. We studied the prevalence, diversity and drivers of haemosporidian parasites (Leucocytozoon, Plasmodium and Haemoproteus) along a latitudinal gradient (30°–56° S), that encompass the total distribution (~3,000 km) of the Thorn-tailed Rayadito (Aphrastura spinicauda) in the South American temperate forests from Chile. We analyzed 516 individuals from 18 localities between 2010 and 2017 and observed an overall prevalence of 28.3% for haemosporidian parasites. Leucocytozoon was the most prevalent parasite (25.8%). We recorded 19 distinct lineages (13 for Leucocytozoon, five for Plasmodium, and one for Haemoproteus). Differences in haemosporidian prevalence and diversity by genus and type of habitat were observed in the latitudinal gradient. Further, we support the existence of a latitudinal associate distribution of Leucocytozoids in South America, where prevalence and diversity increase toward higher latitudes. Distribution of Leucocytozoon was associated with sub-antarctic habitat (higher latitude) and explained by cold temperature and high precipitation. On the other hand, we lacked to find a latitudinal associate pattern for Plasmodium and Haemoproteus, however low prevalence and high diversity were recorded in areas considered as a hotspot of biodiversity in Central Chile. Our findings confirmed the importance of habitat and climatic variables explaining prevalence, diversity and distribution of haemosporidian parasites in a huge latitudinal gradient, belonging the distribution of the Thorn-tailed Rayadito in the world’s southernmost forests ecosystems.
56					2020	Humpback whales extend their stay in a breeding ground in the Tropical Eastern Pacific	Avila I.C., Dormann, C.F.; García, C., Payán, L.F., & Zorrilla, M.X.	breeding site, Cetacea, Colombian Pacific, conservation, environmental changes, G-stock, Gorgona National Park, Megaptera novaeangliae, migration time	During the austral winter, G-stock humpback whales, Megaptera novaeangliae, migrate to the Tropical Eastern Pacific to breed. To analyse if the whale migration times have changed over time, we analysed 31 years (1988-2018) of arrival and departure times to Gorgona National Park, Colombia, an important breeding site. During this period, whales have significantly changed their arrival time, coming now earlier, but their departure time has not changed significantly. Hence, humpback whales now stay 1 month longer than 31 years ago. Humpbacks arrived in Gorgona at the earliest during the beginning of May and stayed at the most until late December. The change observed in the arrival time to breeding grounds could be related to ice sheet mass changes in autumn in Antarctica and increase in population size over the past decades but we were unable to determine which factor is more important in explaining the observed trend. Management decisions in Colombia need to account for a longer stay, specifically restricting anthropogenic activities from 1May to 31December. We urge other researchers to review their data, in case this shift is evident in other regions and management plans need to be updated.
57					2020	Hydrographic conditions during two austral summer situations (2015 and 2017) in the Gerlache and Bismarck straits, northern Antarctic Peninsula	Parra, T., Caicedo Laurido A.L., Iriarte Sánchez, J.D.	Antarctic peninsula, OMP analysis, Water masses, θ-S diagram	Hydrography in the Gerlache and Bismarck straits is described based on data collected in Januaries of 2015 and 2017, during austral summer. These straits are in the northern Antarctic Peninsula (NAP) continental shelf. In the study area, temperature in the surface mixed layer during January 2017 was warmer than recorded in other years, contemporaneous with an extreme decrease in Antarctic sea ice extent at the end of 2016. This was probably caused by warm water advected from the north into Gerlache Strait, a consequence of northeasterly surface winds over the NAP, forced by a Southern Annular Mode (SAM) negative phase. Optimum multiparameter analysis indicated that relatively warm, salty and low-oxygenated modified Circumpolar Deep Water (mCDW) intrudes over the NAP continental shelf and dominates the Bismarck Strait, where it enters the Gerlache Strait, especially through its southern extremity. The mCDW mixes with relatively cold, fresh and recently ventilated modified High Salinity Shelf Water (mHSSW), producing temporal variations in water proportions. HSSW forms in the Weddell Sea and is advected southward along the deep basins of the Bransfield Strait, entering as bottom water into Gerlache Strait via its northern limit. There were two fronts in Gerlache Strait during both summers. First was a surface thermal front in the mixed layer represented by the 1 °C isotherm (~64.5°S), which separated colder waters toward Bismarck Strait. Second was a sub-pycnocline front, represented by the 0.4 °C and 220 μmol kg−1 dissolved oxygen contours below ~100 dbar, which separated mCDW toward Bismarck Strait from mHSSW on the northern side of the strait. This frontal position varies as a consequence of temporal variations in source water fractions. Moreover, changes in Ekman transport, forced by enhanced westerly winds associated with a SAM positive phase, appeared responsible for a major fraction of mCDW in Gerlache Strait during 2015 relative to 2017. The spatiotemporal variability of source water mixing in the water column structure of the Gerlache Strait might have implications for local biological and chemical cycles, and for regional climate feedbacks, because warm mCDW accelerates glacier retreat in the western Antarctic Peninsula.
58					2020	Beach litter distribution in Admiralty Bay, King George Island, Antarctica	Anfuso G., Bolívar-Anillo, H.J., Asensio-Montesinos, F., Portantiolo Manzolli, R., Portz L., & Villate Daza, D.A.	Foam, Plastic items, Raman spectroscopy, Wood fragments	In the Antarctic Peninsula, most important activities are touristic visits, from the second half of the 20th Century, and scientific investigation linked to 75 research stations. Beach litter content/abundance was investigated at 17 beaches in Admiralty Bay (King George Island, Antarctica) and the type of plastic material was determined by Raman spectroscopy. An average value of 0.16 items m−1 was observed. Wood items consisted of processed wood fragments representing 47.27% of the total. Foam represented 21%, hard plastic pieces 9.68% (consisting of polyvinyl chloride or high density polyethylene), metal 3.37%, rubber fragments 2.81%, foamed plastic pieces 2.66% (composed by polystyrene), the rest of categories representing less than 2% of the total. Wood debris and metal are essentially remnant objects of ancient whaling activities and research expeditions, polyurethane and expanded polystyrene materials have different origins and hard plastic, rubber, paper/cardboard and paint fragments seem mostly linked to present research activities.
59					2021	Interannual Climate Variability in theWest Antarctic Peninsula under Austral Summer Conditions	Santamaría-del-Ángel, E., Cañon-Páez, M., Sebastiá-Frasquet, M., González-Silveira, A., Gutierrez, A., Aguilar-Maldonado, J., López-Calderón, J., Camacho-Ibar, V, Franco-Herrera, F., & Castillo-Ramírez, A.	climate variability, West Antarctic Peninsula (WAP), SST, multi-sensor LAC imagery, five-year warm cycle, Southern Annular Mode (SAM)/Antarctic Oscillation (AAO), Southern Oscillation Index (SOI), WAP marine ecoregions, Group on Earth Observations (GEO).	This study aimed to describe the interannual climate variability in the West Antarctic Peninsula (WAP) under austral summer conditions. Time series of January sea-surface temperature (SST) at 1 km spatial resolution from satellite-based multi-sensor data from Moderate Resolution Imaging Spectrometer (MODIS) Terra, MODIS Aqua, and Visible Infrared Imager Radiometer Suite (VIIRS) were compiled between 2001 and 2020 at localities near the Gerlache Strait and the Carlini, Palmer, and Rothera research stations. The results revealed a well-marked spatial-temporal variability in SST at the WAP, with a one-year warm episode followed by a five-year cold episode. Warm waters (SST > 0 °C) reach the coast during warm episodes but remain far from the shore during cold episodes. This behavior of warm waters may be related to the regional variability of the Antarctic Circumpolar Current, particularly when the South Polar Front (carrying warm waters) reaches the WAP coast. The WAP can be divided into two zones representing two distinct ecoregions: the northern zone (including the Carlini and Gerlache stations) corresponds to the South Shetland Islands ecoregion, and the southern zone (including the Palmer and Rothera stations) corresponds to the Antarctic Peninsula ecoregion. The Gerlache Strait is likely situated on the border between the two ecoregions but under a greater influence of the northern zone. Our data showed that the Southern Annular Mode (SAM) is the primary driver of SST variability, while the El Niño Southern Oscillation (ENSO) plays a secondary role. However, further studies are needed to better understand regional climate variability in the WAP and its relation with SAM and ENSO; such studies should use an index that adequately describes the ENSO in these latitudes and addresses the limitations of the databases used for this purpose. Multi-sensor data are useful in describing the complex climate variability resulting from the combination of local and regional processes that elicit different responses across the WAP. It is also essential to continue improving SST approximations at high latitudes.
60					2021	Site Selection of the Colombian Antarctic Research Station Based on Fuzzy-Topsis Algorithm	Jairo R. Coronado-Hernández, Wilson A. Rios-Angulo, Camilo Segovia, Diana Urrego-Niño & Alfonso R. Romero-Conrado	Site selection, Fuzzy TOPSIS, Antarctic station.	By 2025 the Republic of Colombia aims to be an advisory member of the Antarctic Treaty System (ATS) and the installation of a scientific station is necessary to upscale the scientific capabilities. The aim of this paper is showing the results of the implementation of a Fuzzy TOPSIS algorithm for site selection of the Colombian Antarctic Scientific Station. A three-phase methodology was proposed, and the obtained results allowed to identify the optimum location for the station, considering key success factors and regulatory constraints.
61					2021	Identification of phytoplankton blooms in the Gerlache strait, West Antarctic Peninsula	Cañon Paez, M., & Santamaría del Ángel, E.	Coeficientes de absorción, Índice Bio-optico de florecimientos fitoplanctonicos, Índice de tamaño, Estrecho de Gerlache, fitoplancton	Con la finalidad de identificar florecimientos fitoplanctónicos, se utilizó el índice de propiedades ópticas inherentes (POIíndice) en muestras de agua de la superficie y el máximo de clorofila-a (MPC) que fueron tomadas en la Tercera (enero de 2017) y en la Cuarta Expedición (enero 2018) de Colombia a la Antártida en el Estrecho de Gerlache (EG). El POIíndice se calculó partir de las anomalías espaciales estandarizadas de los coeficientes de absorción del fitoplancton, el detritus y la materia orgánica disuelta coloreada (CDOM) usando la longitud de onda 443. Además se calculó el índice de tamaño del fitoplancton mediante la razón Azul/Rojo y este se relacionó con el POIsíndice para determinar la estructura de tamaño del fitoplancton responsable de los florecimientos. En 2017 se identificó a cuatro estaciones en condiciones de florecimiento, siendo dos superficiales y dos subsuperficiales; a tres en condiciones de descenso del florecimiento y a doce en condiciones de no florecimiento, con una estructura de tamaño diversa donde predominaron poblaciones del micro, nano y del picofiplancton. En 2018 dos estaciones se identificaron en condiciones de florecimiento, siendo uno superficial y otro subsuperficial; a dos en condiciones de descenso del florecimiento y nueve en condiciones de no florecimiento, la estructura de tamaño que domino los florecimientos fue el microfitoplancton. Con el POIsíndice, se observaron en las dos expediciones condiciones susbsuperficiales de florecimientos, probándose además su efectividad para florecimientos generados por condiciones naturales o estacionales en diferentes profundidades de la columna de agua.
62					2021	Contributions to the knowledge of macroalgae of the Gerlache Strait – Antarctica	Rincón Díaz, N., Macaya, E., & Guzmán Henao, S.	Macroalgas, Antártica, Estrecho de Gerlache, Rhodophyta, Ochrophyta, Cambio climático.	Esta investigación es un aporte al conocimiento de algunas especies de macroalgas marinas que fueron recolectadas durante las expediciones científicas “Almirante Padilla” (2016-2017) y “Almirante Campos” (2018-2019), en las que participó el Instituto de Investigaciones Marinas y Costeras-Invemar con el proyecto: Biodiversidad y Condiciones Oceanográficas del Estrecho de Gerlache “Biogerlache-Antártica”. Se realizaron recolectas usando draga tipo Shipek y videos subacuáticos con un ROV (Remote Operated Vehicle). Se identificaron seis especies, cuatro Rhodophyta y dos Ochrophyta-Phaeophyceae. Se incluye información sobre la profundidad y zonación donde las macroalgas fueron halladas, y su relación con registros previos para el área de estudio.
63					2021	Flujos de sedimento glaciomarino en pequeñas bahías de la costa de Danco, península Antártica	Rodrigo, C., Varas-Gómez, A., Grisales, C., Quintana-Saavedra, D., & Molares, R.	Ambiente glaciomarino, plumas de sedimentos, turbidez, variables oceanográficas, glaciar de marea.	El calentamiento atmosférico global y el aumento de las temperaturas oceánicas pueden contribuir a la aceleración del derretimiento de los glaciares e influir en la generación y en las características físicas de flujos de sedimentos en bahías y fiordos de la península Antártica. Durante la Primera Expedición Científica de Colombia a la Antártica, llevada a cabo entre enero y febrero de 2015, se midieron variables hidrográficas (temperatura, salinidad, presión y turbidez) en la columna de agua, desde muy cerca del frente glaciar principal hacia costa afuera, en 5 bahías de la costa de Danco, península Antártica occidental. Se identificaron plumas de sedimento glaciomarino provenientes del glaciar de marea en todas las bahías, sin embargo, con extensiones espaciales variables así también en la concentración de sedimentos, siendo aquellas de la zona central de la costa de Danco, las más extensas y concentradas. Por comparación con años anteriores, en este trabajo se registró en promedio mayores concentraciones de partículas. El mayor flujo de sedimentos glaciomarinos se podría asociar con un mayor derretimiento glaciar, entre otros posibles factores.
64					2021	Relatos del confín del mundo (y del Universo). En busca de Antártida, el último lugar de la Tierra. Una ventana al cosmos	Soler, J.		En el extremo sur de nuestro planeta se esconde un territorio que fue desconocido para los humanos durante la mayor parte de su historia: Antártida. Durante siglos, los más audaces exploradores cruzaron los océanos y protagonizaron extraordinarias hazañas en búsqueda de sus costas. Cuando sus barcos lograron sortear el embate del frío lacerante, el embrujo de sus días sin noche y la amenaza de los enormes témpanos, el que ha sido llamado “el último lugar de la Tierra” se convirtió en una obsesión. Como los astronautas en los tiempos modernos, los humanos atravesaron una nueva frontera y se internaron como hormigas en este inconmensurable desierto de hielo para coronar con sus banderas el punto más austral del mundo. Esta es su historia.
65					2021	Peligros de la operación aérea en la Antártida para gestionar la seguridad operacional de la Fuerza Aérea Colombiana	Tabares Gómez, W.	Antártida, evaluación de riesgos, panorama de riesgos, seguridad operacional.	La actividad aérea en la Antártida es considerada de riesgo, debido a las bajas temperaturas del ambiente y las condiciones topográficas. La Fuerza Aérea Colombiana (FAC) ha realizado operaciones en el territorio antártico desde 2015, y proyecta su incremento en un futuro cercano. Por lo anterior, el objetivo de este artículo fue identificar los peligros de la operación aérea en la Antártida para gestionar la seguridad operacional de la FAC. Para tal fin, se realizó un estudio transversal mixto no experimental durante la misión antártica de la FAC en el verano austral 2019-2020, y se utilizó la metodología de panorama de riesgos operacionales vigente en la FAC. El panorama de riesgos obtenido mostró a la salida de pista el congelamiento y los factores humanos como los de mayor riesgo para la operación, situación que coincide con lo reportado en la literatura. Con la información recolectada se elaboró una herramienta para mitigación del riesgo operacional de la FAC en misiones polares. Finalmente, para la gestión del riesgo de las operaciones aéreas de la FAC en la Antártida, se concluyó que el núcleo fundamental radica en la capacitación permanente del personal involucrado en operaciones polares, las cuales se encuentran entre las de mayor riesgo dentro de la actividad aérea. Además, se recomienda actualizar o revisar el panorama de riesgos al menos una vez cada seis meses, con el fin de investigar las últimas tendencias meteorológicas predominantes en el continente blanco, ya que el calentamiento global y el cambiante clima podrían arrojar fenómenos que no se hayan identificado en el presente estudio.
66					2021	Annotated and illustrated list of echinoderms collected during the Colombian scientific expeditions to the Antarctica (2016-2019)	Borrero-Pérez G.H. & Yepes-Gaurisas D.	Asteroidea, Biogerlache project, Crinoidea, Holothuroidea, Ophiuroidea.	In order to contribute to the base line of knowledge that is being built of the Gerlache Strait and the adjacent areas, the echinoderms collected during the Scientific Expeditions from Colombia to Antarctica carried out between 2016 and 2019 as part of the project “Biodiversity and oceanographic conditions of the Gerlache Strait, Biogerlache-Antartica” are presented. Eleven stations between 54 and 523 m deep were sampled, using sediment dredgers that captured incidentally some individuals from the mega and macro-epifauna, which were separated, reviewed and identified. Twentynine (29) individuals were obtained in five of the sampled stations, belonging to 13 morphotypes. Ophiuroidea was the richest class (five morphotypes), followed by Holothuroidea (four), Asteroidea (two) and Crinoidea (two). Morphological and distribution comments are presented, as well as general and detailed images of each morphotype. Among the contributions to the inventory of echinoderms in the area, it is highlighted the sea cucumber genus Taeniogyrus Semper, 1867 that is registered for the first time for the Antarctic peninsula and the crinoid species Anthometrina adriani (Bell, 1908) that extends its geographical distribution, confined to the high-Antarctic shelf, up to the Gerlache Strait (64° 39 ‘S).
67					2021	Epipelagic euphausiids assemblage in the Gerlache Strait (Antarctic Peninsula) during January 2015	Rivera-Gómez, M., Giraldo, A., Mojica-Moncada, D.F.	Antarctic Ocean, Austral summer, Euphausiacea, Salinity, Temperature.	The spatial distribution of the epipelagic Euphausiids was investigated during the first Colombian Scientific Expedition to Antarctica “Expedición Caldas” in the Gerlache Strait during the austral summer of 2015. Surface zooplankton was collected at 20 oceanographic stations with a simple conical net of 0.6 m in diameter mouth and 200 μm of mesh net. Four euphausiid species were collected in 70 % of the sampling stations: Euphausia crystallorophias Holt and Tattersall 1906, Euphausia superba Dana 1850, Thysanoessa sp. and Thysanoessa macrura Sars 1883. Euphausia crystallorophias was the most abundant species with maximum density of 818 ind 1000 m-3 associated with the entrance of the Wilhelmina Bay, in the central area of the Gerlache Strait. The northern and southern sectors of the strait had significant differences in surface temperature and salinity associated with significant differences in the composition of the euphausiid species assemblages between both sectors. Although E. crystallorophias was the numerically dominant euphausiid species in the Gerlache Strait, E. superba was mostly distributed in the northern sector while Thysanoessa sp. was only distributed in the southern sector.
68					2021	Ornithogenic Factor of Soil Formation in Antarctica: A Review	Abakumov, E.V., Parnikoza, I.Y., Zhianski, M., Yaneva, R., Lupachev, A.V., Andreev, M.P., Vlasov, D.Y., Riano, J., & Jaramillo, N.	Antarctic soil formation, biogeochemistry, ornithochory, ornithogenic and non-ornithogenic, soils.	The role of ornithogenic factor in the formation of soils and soil cover patterns in continental and maritime Antarctica is considered. The results of long-term soil studies at key sites in coastal oases of East Antarctica (Larsemann Hills, the Haswell Islands) and on the Subantarctic islands (King George Island, Livingston Island, the Argentine Islands) are summarized. The influence of the penguin rookeries on the morphology and physicochemical properties of soils is shown. These rookeries determine the vast spatial zones of biogeochemical influence on the environment around themselves. Special attention is paid to the phenomenon of ornithochory, which is maintained by the flying seabirds (skuas, albatrosses, terns, petrels, etc.) and is manifested in redistribution of vegetation, soil material, and meso- and microbiota to the areas that were previously free of vegetation and soil cover (periglacial areas, fresh moraines, rocky outcrops, etc.).
69					2021	Submeso-scale mixing features in the Gerlache Strait Bays (Antarctica)	Mojica, J.Freddy., Holland, D.M. & Monroy, J.	Antarctic Ocean dynamics, Diapycnal mixing, Gerlache Strait, Mixing, Sea ice.	Measurements of turbulence in the ocean are sparse, especially in environments such as Antarctica. Here we map the spatial distribution of diapycnal diffusivities and the water column characteristics across the three main bays in the Gerlache Strait on the western side of the Antarctic Peninsula. The measurements were recorded during the Fifth Colombian Antarctic Expedition, 2018-2019, using a Vertical Microstructure Profiler in free fall for the first 400 m depth, to record fluctuations of vertical shear at dissipation scales (10-3 – 103 m). Diapycnal diffusivities are higher by 1-2 orders of magnitude in the Gerlache mainstream compared with the interior bays, with values from O (log10kρ = -3 m2s-1) to O (log10kρ = -5 m2s-1) respectively over the upper 400 m. The highest mixing values were recorded in the southern section of Gerlache Strait (Flandes Bay) compared to the northern one (Charlotte Bay), indicating better well-mixed water in the south. Observed Hot Spots of higher turbulence levels may be associated with the interaction of the entrance of the Upper Circumpolar Depth Water, the Antarctic Surface Water, and the Weddell Sea Deep Waters with resident waters and topography.
70					2021	Water Cherenkov detector optimization for space weather studies in Antarctic	Otiniano, L., Peña, J., Vega, J., Valera, V.B. & Castromonte, C.		During the last two Peruvian summer campaigns in the Antarctica (2018 and 2019), two separate prototype water Cherenkov detectors of the LAGO project have been tested. As at high latitudes the lower geomagnetic shielding allows for the observation of cosmic rays lower than those at middle latitudes, the installation of a detector in the Antarctica is important for the development of the LAGO space weather program. The objectives fulfilled in the second summer campaign were: a general improvement of the design of the detectors, wi-fi data transmission, autonomous operation, the elimination of light leaking and the optimization of the geometry for better separation of the electromagnetic/muonic components measured in the detector. A comparison between the data obtained in the two Antarctic campaigns is shown, making emphasis in the measured flows and the strategy of using a second trigger level in the acquisition stage in order to perform a pre-processing of the data.
71					2021	Characterization of radionuclides in the marine sediments of Orca Seamount, Admiralty Bay, and Mackellar Cove	Poma-Llantoy, V.R., Mendoza-Hidalgo, P.A., & Ricaurte-Villota, C.	137Cs, 40K, Antarctic, Radiation monitoring, Radioactive contamination.	Contamination by radioactive elements and their transfer through the trophic chain can have harmful effects on ecosystems and human health, therefore its continuous monitoring is important. The present study aimed to characterize the concentration of radionuclides of natural and anthropogenic origin in marine sediments from three areas in the northwest of Antarctica, Orca Seamount, Admiralty Bay and Mackellar Inlet, in order to evaluate possible risk levels, sources and transportation routes. Measurements were made using a high-resolution Canberra spectrometer and methodological precision and accuracy was assessed by analyzing reference materials certified by the International Atomic Energy Agency (IAEA), SOIL-6 and Moss SOIL-447. The results showed a low concentration of 137Cs activity in the marine sediments, decreasing towards the deep zone, validating the atmospheric pathway as the main transport route for this radionuclide of anthropic origin. The activity concentration of radionuclides of natural origin 226Ra and 40K, confirm the volcanic origin of the region, corroborating the geological evolution stages of the sector, and the changes in the source of material to the mantle. The calculated radiation hazard indexes showed that current activity concentrations of radioactive elements do not pose a health risk. It is important in the future to improve the understanding of the relationship between hydrothermalism in the area and the activity concentration of radionuclides of natural origin.
72					2021	Study of the Lange Glacier and its impact due to temperature increase in Admiralty Bay, King George Island, Antarctica	Mojica-Moncada, D.F., Cárdenas, C., Mojica-Moncada, J.F., Brondi, F., Barragán-Barrera, D.C., Marangunic, C., Holland, D., Herrera, A.F., & Casassa, G.	Antarctica, Calving flux, Climate change, Lange Glacier, Melting.	In the western Antarctic Peninsula one of the areas the highest warming in the southern hemisphere has been identified. To characterize this tendency, we selected the Lange Glacier (LG) on King George Island, to evaluate: 1) LG surface temperature and dynamics using stakes with temperature data loggers; 2) LG submerged thickness and sea parameters through bathymetry (BT) and 29 CTD stations in front of LG; 3) glacier front (GF) using BT and a Digital Elevation Model (DEM); 4) change in GF position using DEM and historical data of GF width; 5) Calving flux (QC). Our findings showed 85 % of temperatures were above the 0 °C melting point (mean = 5.0 ± 5.2 °C). The stakes had an average ice loss of 9.3 ± 1.3 cm. The LG mean dynamics was 8.8 ± 1.5 m (0.40 ± 0.70 m/day), corroborated by Sentinel-1 satellite images (Offset Tracking = 0.43 ± 0.01 m/day). An intrusion of external waters warmer in the LG bay was identified, which destabilizes the water column due to convection processes. Our findings together indicated a continuous glacial melt that increases its dynamics due to the increase in temperature, with a contribution of fresh water to the Admiralty Bay. Based on historical results and this study, the LG retracement was estimated in 2,492 m between 1956 and 2019.
73					2021	Benthic polychaetes collected in the III expedición “Admiral Padilla” Austral Summer 2016-2017, to the north of the Antarctic Peninsula	Arteaga-Flórez, C. & Bolaño-Lara, M.	Annelida, Biodiversity, Biogerlache, Macrofauna, Marine benthos.	Polychaeta represents the most diverse class in the phylum Annelida, mainly composed by marine organisms, with some terrestrial and freshwater representatives. The present work records the information of the benthic polychaetes, which were collected in four stations in the northern sector of the Antarctic Peninsula, in the III Expedición “Admiral Padilla” verano austral 2016-2017, including taxonomy, relative abundance and frequency of occurrence by family. A total of 326 individuals were quantified, distributed in 12 families: Apistobranchidae, Capitellidae, Cirratulidae, Dorvilleidae, Maldanidae, Nereididae, Orbiniidae, Paraonidae, Serpulidae, Sigalionidae, Spionidae and Syllidae, and the suborder Terebelliformia. Cirratulidae, and Paraonidae were predominant in terms of abundance and frequency. A previous taxonomic analysis has shown morphological variability in the families Cirratulidae, Dorvilleidae, Maldanidae, Paraonidae and Syllidae, and the suborder Terebelliformia. The samples were processed, and deposited at the Marine Natural History Museum of Colombia (MHNMC) – Makuriwa from the Marine and Coastal Research Institute “José Benito Vives de Andréis – Invemar.
74					2021	General description of some meteo-marine variables of surface waters adjacent to the Palmer Archipelago, Antarctic Peninsula, during 1979-2018 based on Era5 data	Duarte, M.A.H., Villegas Bolaños, Nancy., & Perdomo, A.E.C.	Bismarck Strait, Climatology, Gerlache Strait, Sea ice cover, Trends.	A spatial and temporal description of meteo-marine parameters for 1979-2018 period of the marine region surrounding the Palmer Archipelago, located West of the Antarctic Peninsula (WAP), is presented. The used information was extracted from the ERA5 reanalysis. Air Temperature (Ta), Total Precipitation (TP) and Sea Surface Temperature (SST) showed a general increase over the last 40 years in the study region. The highest increase of Ta, TP and SST values were recorded north of Gerlache Strait, followed by Bismarck Strait. It was evidenced that Sea Ice Cover (SIC) has decreased mostly north of Palmer Archipelago. The existence of a local differentiation of meteo-marine conditions around the Palmer Archipelago was identified. The climatology of five reference points in the region showed more visible differences during the austral winter in Ta and SIC, these were appreciated during the austral summer in SST and a bimodal behavior was recorded in Pr. The rate of change during the 1979-2018 period for Ta was 0.011 ºC/year, for Pr it was 0.008 mm/year, for SST it was 0.004 ºC/year and for SIC it was -0.003 fraction/year.
75					2021	Glacimarine sediment flows in small bays on the danco coast, Antarctic Peninsula	Rodrigo, C., Varas-Gómez, A., Grisales, C., Quintana-Saavedra, D., & Molares, R.	Glacimarine environment, Oceanographic Variable, Sediment plume, Tidewater Glacier, Turbidity	Global atmospheric warming and rising ocean temperatures can contribute to the acceleration of glacier melting and influence the generation and physical characteristics of sediment flows in bays and fjords of the Antarctic Peninsula. During the First Scientific Expedition of Colombia to the Antarctic, carried out between January and February 2015, hydrographic variables (temperature, salinity, pressure and turbidity) were measured in the water column, from very close to the main glacier front towards the offshore, on 5 bays of the Danco Coast, Western Antarctic Peninsula. Glacimarine sediment plumes from the tidewater glacier were identified in all bays, however, with varying spatial extensions as well as the concentration of sediments, being those of the central area of the Danco Coast, the most extensive and concentrated. By comparison with previous years, in this work higher average particle concentrations were recorded. The greater flow of glaciomarine sediments could be associated with greater glacial melting, among other possible factors.
76					2021	Identification of phytoplankton blooms in the Gerlache Strait, West Antarctic Peninsula	Cañón, Páez M.L. & Santamaria del Ángel, E.	Absorption coefficients, Gerlache Strait, Inherent optical properties index, Phytoplankton, Size index	In order to identify phytoplankton blooms, the inherent optical properties index (IOPIndex) was used in surface water samples and the maximum chlorophyll-a (MPC) that were taken in the Third (January 2017) and in the Fourth Expedition (January 2018) from Colombia to Antarctica in the Gerlache Strait (EG). The IOPIndexis calculated from the standardized spatial anomalies of the phytoplankton, detritus and colored dissolved organic matter (CDOM) absorption coefficients using wavelength 443. In addition, the phytoplankton size index was calculated using the Blue / Red ratio and this related to the IOPIndexto determine the size structure of the phytoplankton responsible for the blooms. In 2017, four stations were identified under bloom conditions, where two were superficial blooms and two subsurface bloom; to three in conditions of decrease of the bloom and to twelve in conditions of non-bloom, with a structure of diverse size where populations of the micro, nano and the picophytoplankton predominated. In 2018, two stations were identified in bloom conditions, being one superficial bloom and the other subsurface bloom; to two in conditions of decrease in bloom and nine in conditions of non-bloom, the size structure that dominated the blooms was microphytoplankton. With the IOPIndex, subsurface bloom conditions were observed in both expeditions, also proving their effectiveness for blooms generated by natural or seasonal conditions at different depths of the water column.
77					2021	Benthic molluscs collected in Western Antarctica during the “Caldas”, “Admiral Padilla” and “Admiral Campos” expeditions, southern summers 2014-2015, 2016-2017 and 2018-2019	Osorno-Arango, A., & Cantera-Kintz, J.	Bransfield Strait, Gerlache Strait, Mollusca, Southern Ocean, West Antarctica.	This research is part of the results of the three first expeditions of Colombia to West Antarctica and it focused on the systematics and taxonomic diversity of the benthic community of molluscs collected between 5 and 400 m deep. The Sampling sites where mollusks were collected were located along the Gerlache and Bransfield straits, around the Palmer Archipelago and the South Shetland Islands, adjacent to the Antarctic Peninsula. The list of identified species that are deposited in the Museum of Marine Natural History of Colombia – Makuriwa, of the Institute of Marine and Coastal Research “José Benito Vives de Andréis” -Invemar, is presented. This inventory consisted of 15 specimens distributed in 10 taxa, of which 7 were shelled gastropods (including 5 microgastropods) and 3 were bivalves. Four microgastropods were placed in greater taxonomic categories due to the low knowledge of these taxa in the region (Anatoma sp., Cingulopsoidea sp., Truncatelloidea sp. and Eatoniella sp.). The other gastropod species (3) were Margarella antarctica, Prosipho turritus and Nacella concinna. The bivalves found were Philobrya sublaevis, Adacnarca nitens and Thracia meridionalis. The identified species have previously been recorded in West Antarctica. Some of them, like the bivalves, show a circumantarctic distribution. Nacella concinna was the most abundant taxon. In coherence with the general objective of the “BioGerlache-Antarctica” project, the results generate contributions to the biological inventories of Antarctica, contributing to expand the information to define possible conservation areas in the future.
78					2021	Migratory connections among breeding grounds off the Eastern Pacific and feeding areas in the Antarctic Peninsula based on genotype matching	Caballero, S., Steel, D., Pallin, L., Botero-Acosta, Natalia., Felix, F., Olavarría, C., Diazgranados, M.C., Bessudo, S., Friedlander, A., & Baker, C.S.	Genotyping, Megaptera novaeangliae, Microsatellite, Migratory connectivity, Southeastern Pacific.	We analysed 114 DNA samples collected in different locations within the stock G breeding grounds, including Ecuador and the northern and southern Pacific of Colombia. We genotyped 15 microsatellite loci, sexed all samples, and performed genotype comparisons. Genotype comparisons were done using a DNA register of previously genotyped individuals from the Colombian breeding ground and the Antarctic Peninsula feeding Area. We confirmed connectivity between feeding grounds in Antarctic Peninsula and breeding grounds in Colombia and Ecuador using microsatellite loci. We found recaptures within each sampling location in the same year, but we also found a few recaptures in the same locations between years both in breeding and feeding grounds. Interestingly, we found recaptures between breeding and feeding grounds using samples collected 20 years apart, providing some information about longevity in this stock. Further comparisons with other data sets (Brazil, North Pacific) are needed to understand the migratory connectivity of this stock.
79					2021	Insights into the genetic diversity of the leopard seal (Hydrurga leptonyx), inferred from mitochondrial DNa analysis, at Danco Coast, antarctic Peninsula	Hernández-Ardila, L.V., Barragán-Barrera, D.C., Negrete, J., Poljak, S., Riet-Sapriza, F.G., & Caballero, Susana.	Antarctica, Control Region, MtDNA, Pinnipeds, Seal.	The leopard seal (Hydrurga leptonyx) is a genetically low-studied species. In order to conduct the first genetic diversity assessment of this species in Danco Coast (Antarctic Peninsula), 423 bp of the mitochondrial DNA Control Region (mtDNA-CR) was sequenced from 13 blood samples collected in Primavera Base (62°15’S, 58°39’W) during the 2011-2012 austral summer. Our results showed high haplotype diversity (h = 0.99), with various divergent haplotypes. Our findings suggest that leopard seals in the Danco Coast could represent different phylogroups; however, including more genetic markers are needed to confirm this hypothesis.
80					2021	Copepods, hydromedusae and siphonophores: Diversity and distribution in the Gerlache Strait, Antarctic Peninsula	Dorado-Roncancio, E.F, & Cedeño-Posso, C.	Antarctic Ocean, Dimophyes arctica, Diversity, Metridia gerlachei, Zooplankton	Project Biodiversity and oceanographic conditions of the strait of Gerlache “Biogerlache-Antarctica”, aims to carry out the characterization of the Antarctic fauna of the strait, generating new contributions to the biological inventories of Antarctica. Present work focuses on the biodiversity of the zooplanktonic community, specifically on copepods, hydromedusae and siphonophorae collected during the III Antarctic Expedition of Colombia “Admiral Padilla” (2016-2017). Sampling was carried out in seven oceanographic stations located along the Gerlache strait, with vertical trawls between the maximum depth of the station and the surface. 4100 organisms belonging to 38 species of the phylum Arthropoda (Orders Calanoid and Cyclopoid) and 10 species of the phylum Cnidaria (Subclasses Hydroidolina and Trachylina) were identified. Copepods families with the greatest richness of genera are Aetideidae and Metridinidae, with Metridia gerlachei, Chiridius polaris and Gaetanus tenuispinosus being frequent species in more than 50 % of the stations. Identified species are common to the Antarctic Peninsula (Bellingshausen Sea, Scotia Sea and the Weddell Sea), also the range of four copepods are extended for the epipelagic and mesopelagic waters of the Gerlache Strait. Other frequent species are the hydromedusae Arctapodema sp. and Solmundella bitentaculata and the siphonophores Dimophyes arctica and Diphyes antarctica, the latter being collected in both polygastric and eudoxic forms (the dominant form in all stations).
81					2022	Redescription of Microspio moorei (Gravier, 1911) (Annelida: Spionidae) with inclusion of a taxonomic key for all the species of the genus	Fonseca González, I., Londoño-Mesa, M., & Delgado-Blas, V.	Annelida, Taxonomy, Antarctic Peninsula, morphological variation, Programa Antártico Colombiano.	Microspio moorei (Gravier, 1911), described from Admiralty Bay, King George Island (Antarctic Peninsula), has not been recorded since the original description, based on a single specimen, the holotype. Thus, subsequent comments and observations about the species have been made based only on the original description and with no information on morphological variations of the species. A re-description of this species is presented based on new material collected from a bay near the type locality, with detailed descriptions and illustrations of morphological characters. A key to all species of Microspio Mesnil, 1896 is provided. This research was part of the Colombian Antarctic Program, in collaboration with the Chilean Antarctic Institute (INACH).
82					2022	Iceberg Motion in the Gerlache Strait	Dr Serguei Lonin	gerlache strait; hydrodynamic model; icebergs.	The First Colombian Scientific Expedition to the Antarctic was carried out during the summer period of the South Hemisphere (January-February 2015) in the Gerlache Strait located by the Antarctic Peninsula. One of the most important investigation tasks during the expedition was the need of having a short-term forecast system of icebergs’ trajectories which would help to improve navigation safety for tourist and oceanographic vessels in the region. This paper characterizes the main mechanisms of iceberg’s motion, their mathematical representation, and discusses some possible improvements to the way that iceberg dynamics are described.
83					2022	Swell Conditions at Potential Sites for the Colombian Antarctic Research Station	Lonin, S., Ríos-Angulo, W. & Coronado, J.	Antarctic Station, Bransfield Strait, South Shetland Island, swell, wave model.	The objective of this paper was to characterize swell conditions in the coastal zone of the South Shetland Islands, where our preliminary analyses evaluated potential locations for the Colombian scientific station. The Simulating Waves Nearshore (SWAN) spectral model was implemented for the Bransfield Strait. The boundary conditions were selected by a cluster analysis of the wave climate from global hindcasting obtained with the WAVEWATCH III model. Some comparisons between the model and wavemeter measurements were made. The results demonstrated that optimal sea state conditions for the scientific base are present in the South Bay, Livingston Island.
84					2022	Spatial distribution of meso- and macro-zooplankton in the Bransfield Strait and around Elephant Island, Antarctic Peninsula, during the 2019–2020 austral summer	Criales-Hernandez, I., Jerez-Guerrero, M., Latandret-Solana, S., Gomez-Sanchez, M.	Zooplankton, Copepoda, Euphausia superba, Salpa thompsoni, Antarctic peninsula.	The Antarctic Peninsula is a region of the world where drastic impacts of climate change have been observed over the past few years, leading the communities inhabiting this area to adapt to new conditions. This is reflected in changes to the composition and abundance of pelagic species, especially zooplankton, which constitute the main food source for the trophic web supporting the ecosystem in this region. In this study, we compared the composition, abundance, and spatial distribution of meso- and macro-zooplankton and how they relate to the oceanographic conditions of the Bransfield Strait and the area surrounding Elephant Island, Antarctic Peninsula, during the 2019–2020 austral summer. The community was represented by three groups: small-sized copepods such as Oithona similis and Ctenocalanus citer, salps such as Salpa thompsoni, and the Euphausiacea. Euphausiacea showed an important decrease in composition and abundance and was only represented by Euphausia superba and Thysanoessa macrura. An increase in the abundance and distribution of S. thompsoni was observed over the entire study area, as well as positive SST anomalies, which possibly favored the increase in the S. thompsoni population, as well as the decrease and displacement of Euphausiacea adults and juveniles. If, as climate models predict, increases in temperatures keep occurring, our results reflect the scenario that will prevail for zooplankton in the Antarctic Peninsula, with effects on distribution and abundance that will lead to the dominance of species that are more successful in warmer conditions
85					2022	Estudio de riesgos en escenarios naturales colombianos con potencial uso para misiones espaciales análogas	Campos Chaparro, C., Corzo Zamora, M., Alvarado Yepes, A., Sequeda Ramón, J., Bejarano Cifuentes, I., & Malpica Hincapié, D.	Desierto, Ecosistema, Escenarios, Innovación, Riesgo.	Las misiones análogas espaciales son una alternativa económica para la realización de investigación y entrenamiento para misiones espaciales frente al espacio en sí. Este método es utilizado por las diferentes agencias y organizaciones del sector espacial alrededor del mundo y ha permitido durante más de 50 años desarrollar los programas de entrenamiento e investigación para las diferentes misiones. Este proyecto tiene como objetivo determinar los tipos de escenarios y misiones análogas que se pueden realizar operativamente en Colombia y la Antártica. Se realizaron cuatro fases: estudio descriptivo observacional basado en revisión bibliográfica y webgrafía, salidas de campo, análisis DOFA de cada escenario y levantamiento del panorama de riesgo. Se concluye con los riesgos identificados para las cuatro áreas de estudio visitadas, 1) Antártica Isla Rey Jorge, 2)Desierto de la Tatacoa, 3) Desierto de Villa de Leyva, 4) Nevado del Ruíz y sus medidas de mitigación.
86					2022	Presence of perchlorate in marine sediments from Antarctica during 2017–2020	Acevedo‑Barrios, R., Rubiano‑Labrador, C., & Miranda‑Castro, W.	Selective electrode, Endocrine disruptor, Environmental fate, South Shetland Islands, Toxicology, Occurrence assessment.	Perchlorate of natural origin is a persistent pollutant that affects thyroid function by inhibiting iodine uptake, and this pollutant is frequently detected in different ecosystems at concentrations that can harm human health. In this study, we measured the perchlorate concentrations in 3,000 marine sediment samples from January to March in 2017, 2018, 2019, and 2020 during the 3rd, 4th, 5th, and 6th Colombian Scientific Expeditions to Antarctica. The sampling zones were located at 15 different points on the South Shetland Islands and Antarctic Peninsula, and they were measured using a selective perchlorate electrode. The concentration data indicate that perchlorate reached a minimum concentration of 90 ppm on Horseshoe Island and a maximum concentration of 465 ppm on Deception Island, suggesting a spatial variation in perchlorate concentrations that can be attributed to the natural formation of this pollutant due to volcanic eruptions. Additionally, homogeneous distribution of perchlorate was not observed in Antarctica.
87					2022	Perchlorate‑reducing bacteria from Antarctic marine sediments / Bacterias reductoras de perclorato de sedimentos marinos antárticos	Acevedo‑Barrios, R., Rubiano‑Labrador, C., Navarro‑Narvaez, D., Escobar‑Galarza, J., González, D., Mira, S., Moreno, D., Contreras, A., & Miranda‑Castro, W.	Extremophiles, Halotolerant bacteria, Psychrotolerant microorganism, Psychrophilic bacteria, Perchlorate biodegradation, Toxicity.	Perchlorate is a contaminant that can persist in groundwater and soil, and is frequently detected in different ecosystems at concentrations relevant to human health. This study isolated and characterised halotolerant bacteria that can potentially perform perchlorate reduction. Bacterial microorganisms were isolated from marine sediments on Deception, Horseshoe and Half Moon Islands of Antarctica. The results of the 16S ribosomal RNA (rRNA) gene sequence analysis indicated that the isolates were phylogenetically related to Psychrobacter cryohalolentis, Psychrobacter urativorans, Idiomarina loihiensis, Psychrobacter nivimaris, Sporosarcina aquimarina and Pseudomonas lactis. The isolates grew at a sodium chloride concentration of up to 30% and a perchlorate concentration of up to 10,000 mg/L, which showed their ability to survive in saline conditions and high perchlorate concentrations. Between 21.6 and 40% of perchlorate was degraded by the isolated bacteria. P. cryohalolentis and P. urativorans degraded 30.3% and 32.6% of perchlorate, respectively. I. loihiensis degraded 40% of perchlorate, and P. nivimaris, S. aquimarina and P. lactis degraded 22%, 21.8% and 21.6% of perchlorate, respectively. I. loihiensis had the highest reduction in perchlorate, whereas P. lactis had the lowest reduction. This study is significant as it is the first finding of P. cryohalolentis and. P. lactis on the Antarctic continent. In conclusion, these bacteria isolated from marine sediments on Antarctica offer promising resources for the bioremediation of perchlorate contamination due to their ability to degrade perchlorate, showing their potential use as a biological system to reduce perchlorate in high-salinity ecosystems.
88					2022	Pseudomonas strains from the Livingston Island, Antarctica: a source of cold-active hydrolytic enzymes / Cepas de Pseudomonas de la isla Livingston, Antártida: una fuente de enzimas hidrolíticas activas en frío	Rubiano Labrador Carolina; Acevedo Barrios Rosa; García Lázaro Alba; Ward Bowie Lilia, Támara Acosta Ana Karina; Mercado Molina Blanca	Amylase, cellulose, extracellular enzymes, polar environments, protease.	Pseudomonas spp. is considered one of the most successful bacterial genera due to its plasticity and metabolic versatility, which has allowed it to colonize different ecosystems, including Antarctica. The ability of Pseudomonas to adapt and survive in the hostile conditions of the Antarctic makes them a reservoir of enzymes that can be used in different biotechnological applications; however, research on this genus in Antarctica is still in its infancy. Therefore, the aim of this study was to isolate and characterise cold-adapted Pseudomonas from Livingston Island, Antarctica, and explore their ability to produce cold-active hydrolytic enzymes. In the present study, we isolated seven cold-adapted bacteria related to the genus Pseudomonas. The isolated strains have the ability to produce hydrolytic enzymes. These results demonstrate that cold-adapted Pseudomonas from Antarctica are a promising source of cold-active enzymes with biotechnological potential.
89					2022	Variation in blubber cortisol levels in a recovering humpback whale population inhabiting a rapidly changing environment	Pallin L.J.; Botero-Acosta Natalia.; Steel D.; Baker C.S.; Casey C.; Costa D.P.; Goldbogen J.A.; Johnston D.W.; Kellar N.M.; Modest M.; Nichols R.; Roberts D.; Roberts M.; Savenko O.; Friedlaender A.S.		Glucocorticoids are regularly used as biomarkers of relative health for individuals and populations. Around the Western Antarctic Peninsula (WAP), baleen whales have and continue to experience threats, including commercial harvest, prey limitations and habitat change driven by rapid warming, and increased human presence via ecotourism. Here, we measured demographic variation and differences across the foraging season in blubber cortisol levels of humpback whales (Megaptera novaeangliae) over two years around the WAP. Cortisol concentrations were determined from 305 biopsy samples of unique individuals. We found no significant difference in the cortisol concentration between male and female whales. However, we observed significant differences across demographic groups of females and a significant decrease in the population across the feeding season. We also assessed whether COVID-19-related reductions in tourism in 2021 along the WAP correlated with lower cortisol levels across the population. The decline in vessel presence in 2021 was associated with a significant decrease in humpback whale blubber cortisol concentrations at the population level. Our findings provide critical contextual data on how these hormones vary naturally in a population over time, show direct associations between cortisol levels and human presence, and will enable comparisons among species experiencing different levels of human disturbance.
90					2022	Evolutionary and Biogeographical History of Penguins (Sphenisciformes): Review of the Dispersal Patterns and Adaptations in a Geologic and Paleoecological Context	Pelegrín J.S., & Hospitaleche C.A.	Aves, paleobiogeography, penguins, phylogenies, Sphenisciformes.	Despite its current low diversity, the penguin clade (Sphenisciformes) is one of the groups of birds with the most complete fossil record. Likewise, from the evolutionary point of view, it is an interesting group given the adaptations developed for marine life and the extreme climatic occupation capacity that some species have shown. In the present contribution, we reviewed and integrated all of the geographical and phylogenetic information available, together with an exhaustive and updated review of the fossil record, to establish and propose a biogeographic scenario that allows the spatialtemporal reconstruction of the evolutionary history of the Sphenisciformes, discussing our results and those obtained by other authors. This allowed us to understand how some abiotic processes are responsible for the patterns of diversity evidenced both in modern and past lineages. Thus, using the BioGeoBEARS methodology for biogeographic estimation, we were able to reconstruct the biogeographical patterns for the entire group based on the most complete Bayesian phylogeny of the total evidence. As a result, a New Zealand origin for the Sphenisciformes during the late Cretaceous and early Paleocene is indicated, with subsequent dispersal and expansion across Antarctica and southern South America. During the Eocene, there was a remarkable diversification of species and ecological niches in Antarctica, probably associated with the more temperate climatic conditions in the Southern Hemisphere. A wide morphological variability might have developed at the beginning of the Paleogene diversification. During the Oligocene, with the trends towards the freezing of Antarctica and the generalized cooling of the Neogene, there was a turnover that led to the survival (in New Zealand) of the ancestors of the crown Sphenisciform lineages. Later these expanded and diversified across the Southern Hemisphere, strongly linked to the climatic and oceanographic processes of the Miocene. Finally, it should be noted that the Antarctic recolonization and its hostile climatic conditions occurred in some modern lineages during the Pleistocene, possibly due to exaptations that made possible the repeated dispersion through cold waters during the Cenozoic, also allowing the necessary adaptations to live in the tundra during the glaciations.
91					2022	Swell Conditions at Potential Sites for the Colombian Antarctic Research Station	Lonin S., Rios-Angulo, W.A., & Coronado, J.	Antarctic Station, Bransfield Strait, South Shetland Islands, Swell, Wave model.	The objective of this paper was to characterize swell conditions in the coastal zone of the South Shetland Islands, where our preliminary analyses evaluated potential locations for the Colombian scientific station. The Simulating Waves Nearshore (SWAN) spectral model was implemented for the Bransfield Strait. The boundary conditions were selected by a cluster analysis of the wave climate from global hindcasting obtained with the WAVEWATCH III model. Some comparisons between the model and wavemeter measurements were made. The results demonstrated that optimal sea state conditions for the scientific base are present in the South Bay, Livingston Island.
92					2022	Perchlorate-reducing bacteria from Antarctic marine sediments	Acevedo-Barrios, R., Rubiano-Labrador, C., Navarro-Narvaez, D., Escobar-Galarza, J., González, D., Mira, S., Moreno, D., Contreras, A., & Miranda-Castro, W.	Extremophiles, Halotolerant bacteria, Perchlorate biodegradation, Psychrophilic bacteria, Psychrotolerant microorganism, Toxicity.	Perchlorate is a contaminant that can persist in groundwater and soil, and is frequently detected in different ecosystems at concentrations relevant to human health. This study isolated and characterised halotolerant bacteria that can potentially perform perchlorate reduction. Bacterial microorganisms were isolated from marine sediments on Deception, Horseshoe and Half Moon Islands of Antarctica. The results of the 16S ribosomal RNA (rRNA) gene sequence analysis indicated that the isolates were phylogenetically related to Psychrobacter cryohalolentis, Psychrobacter urativorans, Idiomarina loihiensis, Psychrobacter nivimaris, Sporosarcina aquimarina and Pseudomonas lactis. The isolates grew at a sodium chloride concentration of up to 30% and a perchlorate concentration of up to 10,000 mg/L, which showed their ability to survive in saline conditions and high perchlorate concentrations. Between 21.6 and 40% of perchlorate was degraded by the isolated bacteria. P. cryohalolentis and P. urativorans degraded 30.3% and 32.6% of perchlorate, respectively. I. loihiensis degraded 40% of perchlorate, and P. nivimaris, S. aquimarina and P. lactis degraded 22%, 21.8% and 21.6% of perchlorate, respectively. I. loihiensis had the highest reduction in perchlorate, whereas P. lactis had the lowest reduction. This study is significant as it is the first finding of P. cryohalolentis and. P. lactis on the Antarctic continent. In conclusion, these bacteria isolated from marine sediments on Antarctica offer promising resources for the bioremediation of perchlorate contamination due to their ability to degrade perchlorate, showing their potential use as a biological system to reduce perchlorate in high-salinity ecosystems.
93					2022	Changes in rainfall seasonality inferred from weathering and pedogenic trends in mid-Miocene paleosols of La Tatacoa, Colombia	Salazar-Jaramillo, S., Śliwiński, M.G., Hertwig, A.T., Garzón, C.C., Gómez, C.F., Bonilla, G.E., Guerrero, J.	Mi-4 glacial event, Mid-Miocene paleosols, Paleotropics, Pebas system, Rainfall seasonality, Red beds.	The authigenic clay mineral assemblage of paleosol profiles and trends in their bulk geochemical evolution provide insight into the intensity of past chemical weathering regimes. These climate-sensitive weathering products can be used to interpret regional changes of the soil moisture regime, which in turn reflects upon the nature of rainfall seasonality (e.g., unimodal vs. bimodal). A conspicuous color change in the overbank deposits and paleosols of the mid-Miocene Honda Group of La Tatacoa, Colombia, is suggestive of a climatic transition which affected the fauna of La Venta – a mid-Miocene fossiliferous site and significant component of the South American Land Mammal Age (SALMA) classification. This study aims to determine how the paleopedology of this region records the climatic transition that modified the annual patterns of rainfall and soil moisture, forcing a change from the gray-colored paleosols hosted by the La Victoria Formation (~13.6 to ~13.1 Myr) to the red-beds of the Villavieja Formation (~13.1 to 12.0 Myr). In the La Victoria profile, the pedogenic fraction of the clay assemblage indicates that vermiculite, chlorite/HIV mixed-layered clays and high concentrations of base cations (Ca2+, Mg2+, Na+) developed in a poorly drained paleosol under reducing (low Eh) and above-neutral pH conditions. By contrast, the presence of kaolinite, goethite and hematite in the red-beds paleosols implies more oxidizing conditions (high Eh), whereas pedogenic vermiculite and smectite suggest a pH close to or mildly below neutral. A common detrital source (parent material) is inferred for both sets of paleosols. However, more intense chemical weathering towards aluminium rich clay in the Villavieja red-bed fossil soils indicates a change in soil humidity from a poorly drained soil environment of a seasonally flooded wetland system to an alternating regime of humidity and drought on a better drained floodplain. The variation in soil moisture is consistent with a change in seasonality from a unimodal rainfall regime in the case of the La Victoria paleosols to bimodal conditions in the case of the paleosols of the Villavieja Fm. After the establishment of a fully glaciated Antarctica and the global climate transition into the Mi-4 glacial stage at ~13.1 Ma, an increased rate of continental weathering along the paleotropical fringe could have been caused by a stronger temperature gradient between the equator and South Pole, shifting the Intertropical Convergence Zone northward and the rainfall patterns with it.
94					2022	Redescription of Microspio moorei (Gravier, 1911) (Annelida: Spionidae) with inclusion of a taxonomic key for all the species of the genus	Fonseca-González, I., Londoño-Mesa, M.H., Delgado-Blas, V.H.	Antarctic Peninsula, morphological variation, Programa Antártico Colombiano, Taxonomy.	Microspio moorei (Gravier, 1911), described from Admiralty Bay, King George Island (Antarctic Peninsula), has not been recorded since the original description, based on a single specimen, the holotype. Thus, subsequent comments and observations about the species have been made based only on the original description and with no information on morphological variations of the species. A re-description of this species is presented based on new material collected from a bay near the type locality, with detailed descriptions and illustrations of morphological characters. A key to all species of Microspio Mesnil, 1896 is provided. This research was part of the Colombian Antarctic Program, in collaboration with the Chilean Antarctic Institute (INACH).
95					2022	Seismic properties of the permafrost layer using the HVSR method in Seymour-Marambio Island, Antarctica	Vargas C.A.; Solano J.M.; Gulisano A.M.; Santillana S.; Casallas E.A.	Antartic fluids’ saturation, H/V spectral ratio, Marambio, permafrost, seismic response.	Authors have calculated the H/V spectral ratios using seismic-noise recordings in the uppermost layers north of the Seymour-Marambio Island, Antarctic. Sixty-seven seismic site-response measurements near and far from the Argen-tinean Marambio Base runway suggest geotechnical works on the uppermost sedimentary layers due to maintenance, landing, and taxi of large loads and aircraft during decades could contribute to changes in their seismic dynamic response. Two horizontal images of Vp, Vs, and Vp / Vs ratios at 1.0 m and 35.0 m depth show lateral variations in the permafrost properties. Authors interpret that permafrost is emplaced in rocks with different porosities and contrasting fluids saturation at those depths. In shallow strata, the saturation of gases affects mainly the elastic properties. In dee-per strata, where the location of water reservoirs is detected, the primary mechanism of seismic dissipation is anelastic.
96					2022	Spatial distribution of meso- and macro-zooplankton in the Bransfield Strait and around Elephant Island, Antarctic Peninsula, during the 2019–2020 austral summer	Criales-Hernández, M.I., Jerez-Guerrero, M., Latandret-Solana, S.A., & Gómez-Sánchez, M.D.	Antarctic peninsula, Copepoda, Euphausia superba, Salpa thompsoni, Zooplankton.	The Antarctic Peninsula is a region of the world where drastic impacts of climate change have been observed over the past few years, leading the communities inhabiting this area to adapt to new conditions. This is reflected in changes to the composition and abundance of pelagic species, especially zooplankton, which constitute the main food source for the trophic web supporting the ecosystem in this region. In this study, we compared the composition, abundance, and spatial distribution of meso- and macro-zooplankton and how they relate to the oceanographic conditions of the Bransfield Strait and the area surrounding Elephant Island, Antarctic Peninsula, during the 2019–2020 austral summer. The community was represented by three groups: small-sized copepods such as Oithona similis and Ctenocalanus citer, salps such as Salpa thompsoni, and the Euphausiacea. Euphausiacea showed an important decrease in composition and abundance and was only represented by Euphausia superba and Thysanoessa macrura. An increase in the abundance and distribution of S. thompsoni was observed over the entire study area, as well as positive SST anomalies, which possibly favored the increase in the S. thompsoni population, as well as the decrease and displacement of Euphausiacea adults and juveniles. If, as climate models predict, increases in temperatures keep occurring, our results reflect the scenario that will prevail for zooplankton in the Antarctic Peninsula, with effects on distribution and abundance that will lead to the dominance of species that are more successful in warmer conditions.
97					2022	UHPLC-MS Metabolomic Fingerprinting, Antioxidant, and Enzyme Inhibition Activities of Himantormia lugubris from Antarctica	Areche, C., Parra, J.R., Sepulveda, B., García-Beltrán, O., & Simirgiotis, M.J.	Alzheimer, Antarctica, antioxidant, depsides, dibenzofurans, enzyme inhibition, Himantormia, native lichens, phenolics	Himantormia lugubris is a Chilean native small lichen shrub growing in the Antarctica re-gion. In this study, the metabolite fingerprinting and the antioxidant and enzyme inhibitory potential from this species and its four major isolated compounds were investigated for the first time. Using ultra-high performance liquid chromatography coupled to quadrupole-Orbitrap mass spec-trometry analysis (UHPLC-Q-Orbitrap-MS), several metabolites were identified including specific compounds as chemotaxonomical markers, while major metabolites were quantified in this species. A good inhibition activity against cholinesterase (acetylcholinesterase (AChE) IC50: 12.38 ± 0.09 µg/mL, butyrylcholinesterase (BChE) IC50: 31.54 ± 0.20 µg/mL) and tyrosinase (22.32 ± 0.21 µg/mL) enzymes of the alcoholic extract and the main compounds (IC50: 28.82 ± 0.10 µg/mL, 36.43 ± 0.08 µg/mL, and 7.25 ± 0.18 µg/mL, respectively, for the most active phenolic atranol) was found. The extract showed a total phenolic content of 47.4 + 0.0 mg of gallic acid equivalents/g. In addition, antioxidant activity was assessed using bleaching of DPPH and ORAC (IC50: 75.3 ± 0.02 µg/mL and 32.7 ± 0.7 μmol Trolox/g lichen, respectively) and FRAP (27.8 ± 0.0 μmol Trolox equivalent/g) ex-periments. The findings suggest that H. lugubris is a rich source of bioactive compounds with po-tentiality in the prevention of neurodegenerative or noncommunicable chronic diseases.
98					2022	Presence of perchlorate in marine sediments from Antarctica during 2017–2020	Acevedo-Barrios, R., Rubiano-Labrador, C., & Miranda-Castro W.	Endocrine disruptor, Environmental fate, Occurrence assessment, Selective electrode, South Shetland Islands, Toxicology.	Perchlorate of natural origin is a persistent pollutant that affects thyroid function by inhibiting iodine uptake, and this pollutant is frequently detected in different ecosystems at concentrations that can harm human health. In this study, we measured the perchlorate concentrations in 3,000 marine sediment samples from January to March in 2017, 2018, 2019, and 2020 during the 3rd, 4th, 5th, and 6th Colombian Scientific Expeditions to Antarctica. The sampling zones were located at 15 different points on the South Shetland Islands and Antarctic Peninsula, and they were measured using a selective perchlorate electrode. The concentration data indicate that perchlorate reached a minimum concentration of 90 ppm on Horseshoe Island and a maximum concentration of 465 ppm on Deception Island, suggesting a spatial variation in perchlorate concentrations that can be attributed to the natural formation of this pollutant due to volcanic eruptions. Additionally, homogeneous distribution of perchlorate was not observed in Antarctica.
99					2022	A phylogenetic study to assess the link between biome specialization and diversification in swallowtail butterflies	Gamboa, S., Condamine, F.L., Cantalapiedra, J.L., Varela, S., Pelegrín, J.S., Menéndez, I., Blanco, F., & Hernández Fernández, M.	bioclimatology, ecological specialization, macroecology, macroevolution, Papilionidae, resource-use, speciation.	The resource-use hypothesis, proposed by E.S. Vrba, states that habitat fragmentation caused by climatic oscillations would affect particularly biome specialists (species inhabiting only one biome), which might show higher speciation and extinction rates than biome generalists. If true, lineages would accumulate biome-specialist species. This effect would be particularly exacerbated for biomes located at the periphery of the global climatic conditions, namely, biomes that have high/low precipitation and high/low temperature such as rainforest (warm-humid), desert (warm-dry), steppe (cold-dry) and tundra (cold-humid). Here, we test these hypotheses in swallowtail butterflies, a clade with more than 570 species, covering all the continents but Antarctica, and all climatic conditions. Swallowtail butterflies are among the most studied insects, and they are a model group for evolutionary biology and ecology studies. Continental macroecological rules are normally tested using vertebrates, this means that there are fewer examples exploring terrestrial invertebrate patterns at global scale. Here, we compiled a large Geographic Information System database on swallowtail butterflies’ distribution maps and used the most complete time-calibrated phylogeny to quantify diversification rates (DRs). In this paper, we aim to answer the following questions: (1) Are there more biome-specialist swallowtail butterflies than biome generalists? (2) Is DR related to biome specialization? (3) If so, do swallowtail butterflies inhabiting extreme biomes show higher DRs? (4) What is the effect of species distribution area? Our results showed that swallowtail family presents a great number of biome specialists which showed substantially higher DRs compared to generalists. We also found that biome specialists are unevenly distributed across biomes. Overall, our results are consistent with the resource-use hypothesis, species climatic niche and biome fragmentation as key factors promoting isolation.
100					2023	Psychrobacter sp: perchlorate reducing bacteria, isolated from marine sediments from Margarita Bay, Antarctica	Rubiano Labrador, Carolina; Acevedo Barrios, Rosa; Jorgelina, Pasqualino, Isis Hernández Rocha; Puentes Martínez, Dainis; Chavarro-Mesa, Edisson; De la Parra-Guerra, Ana C.	Extreme environments, halotolerant bacteria, marine sediments, polar environments, toxicity.	Perchlorate (ClO4-) is an ion that occurs naturally in Antarctica, it is considered an emerging pollutant because it is a powerful endocrine disruptor that affects the functioning of the thyroid gland and the growth and development of humans and biota. The objective of this study was to characterize salt-tolerant bacteria that reduce (ClO4-) from marine sediments of Bahía Margarita, Antarctica, collected in the V Colombian Scientific Expedition to Antarctica “Almirante Tono” in 2019. The methodology used included three stages: [1] Isolation of the bacteria: for which broth and LB agar modified with seawater were used [2] Morphological and biochemical characterization of the isolated strains: through Gram staining, tests for catalase, oxidase and BBL Crystal; [3] Susceptibility tests (NaCl and ClO4-) and ClO4- reduction test using selective electrode. The bacterial isolates grew at 10 °C for 7 days, tolerated NaCl concentrations up to 20% v/v and (ClO4-) concentrations up to 10,000 mg/L; with pH variations between 6.5 to 12.0. This contaminant was reduced by the isolated strains in percentages between 18% and 41%. The morphological and biochemical characterization of the isolated strains indicated that they were related to the genus Psychrobacter. In conclusion, salt-tolerant bacteria isolated from marine sediments in Margarita Bay, Antarctica are promising resources for bioremediation of (ClO4-) pollution in ecosystems.
101					2023	Propiedades sísmicas del permafrost a través del método de relaciones espectrales horizontal/vertical en la isla Seymour-Marambio de la Antártida	Carlos A. Vargas, Juan M. Solano, Adriana M. Gulisano, Sergio Santillana & Edwin A. Casallas	Relaciones espectrales H/V; respuesta sísmica; permafrost; Marambio; Antártida; saturación de fluidos.	Authors have calculated the H/V spectral ratios using seismic-noise recordings in the uppermost layers north of the Seymour-Marambio Island, Antarctic. Sixty-seven seismic site-response measurements near and far from the Argentinean Marambio Base runway suggest geotechnical works on the uppermost sedimentary layers due to maintenance, landing, and taxi of large loads and aircraft during decades could contribute to changes in their seismic dynamic response. Two horizontal images of Vp, Vs, and Vp/ Vs ratios at 1.0 m and 35.0 m depth show lateral variations in the permafrost properties. Authors interpret that permafrost is emplaced in rocks with different porosities and contrasting fluids saturation at those depths. In shallow strata, the saturation of gases affects mainly the elastic properties. In deeper strata, where the location of water reservoirs is detected, the primary mechanism of seismic dissipation is anelastic.
102					2023	Sex-specific mercury levels in skin samples of southern elephant seals (Mirounga leonina) at Isla 25 de Mayo (King George Island), Antarctic Peninsula	Dalia C. Barragán-Barrera, Federico G. Riet Sapriza, Diego F. Mojica Moncada, Javier Negrete, Antonio Curtosi, Paco Bustamante, Susana Caballero, Andrea Luna Acosta	Antarctica, contamination, elephant seal, heavy metals, Hg, mercury, pinnipeds, South Shetland Islands.	The southern elephant seal (SES; Mirounga leonina) has a circumpolar distribution, breeding mainly on sub-Antarctic islands and making long trips between breeding or molting and foraging areas. Most individuals from colonies in the South Shetland Islands (western Antarctic Peninsula; WAP) are distributed in Antarctic Specially Protected Areas (ASPA). Despite these protected habitats, pollutants can reach such remote areas far away from emission sources, affecting local fauna. To assess possible mercury (Hg) contamination in SES, we analyzed skin samples collected from free-ranging molting individuals using the remote biopsy PAXARMS system in Isla 25 de Mayo/King George Island (62°15′S, 58°39′W; ASPA 132). Hairless skin samples were analyzed to determine total-Hg (THg) concentrations, which ranged between 145 ng/g and 1,915 ng/g (M = 730, SD = 388 ng/g), showing significant differences between sexes, with adult-females having higher concentrations (range = 306–1,915, M = 859, SD = 427 ng/g dw) than subadult-males (range = 145–1,645, M = 629, SD = 329 ng/g dw). These differences may be explained mainly by feeding-niche partitioning between sexes. Females prefer mesopelagic prey or prey associated with sea-ice in the WAP, which are enriched in methylmercury. These results provide insight regarding Hg contamination in top Antarctic predators like SES, and the need to monitor for potential effects of Hg contamination in Antarctic marine mammals.
103					2023	A surplus no more? Variation in krill availability impacts reproductive rates of Antarctic baleen whales	Pallin L.J.; Kellar N.M.; Steel D.; Botero-Acosta Natalia.; Baker C.S.; Conroy J.A.; Costa D.P.; Johnson C.M.; Johnston D.W.; Nichols R.C.; Nowacek D.P.; Read A.J.; Savenko O.; Schofield O.M.; Stammerjohn S.E.; Steinberg D.K.; Friedlaender A.S.	Antarctica, climate change, conservation, humpback whale, krill, pregnancy rates.	The krill surplus hypothesis of unlimited prey resources available for Antarctic predators due to commercial whaling in the 20th century has remained largely untested since the 1970s. Rapid warming of the Western Antarctic Peninsula (WAP) over the past 50 years has resulted in decreased seasonal ice cover and a reduction of krill. The latter is being exacerbated by a commercial krill fishery in the region. Despite this, humpback whale populations have increased but may be at a threshold for growth based on these human-induced changes. Understanding how climate-mediated variation in prey availability influences humpback whale population dynamics is critical for focused management and conservation actions. Using an 8-year dataset (2013–2020), we show that inter-annual humpback whale pregnancy rates, as determined from skin-blubber biopsy samples (n = 616), are positively correlated with krill availability and fluctuations in ice cover in the previous year. Pregnancy rates showed significant inter-annual variability, between 29% and 86%. Our results indicate that krill availability is in fact limiting and affecting reproductive rates, in contrast to the krill surplus hypothesis. This suggests that this population of humpback whales may be at a threshold for population growth due to prey limitations. As a result, continued warming and increased fishing along the WAP, which continue to reduce krill stocks, will likely impact this humpback whale population and other krill predators in the region. Humpback whales are sentinel species of ecosystem health, and changes in pregnancy rates can provide quantifiable signals of the impact of environmental change at the population level. Our findings must be considered paramount in developing new and more restrictive conservation and management plans for the Antarctic marine ecosystem and minimizing the negative impacts of human activities in the region.
104					2023	Baseline concentrations, spatial distribution and origin of trace elements in marine surface sediments of the northern Antarctic Peninsula	Delhaye L.J.; Elskens M.; Ricaurte-Villota C.; Cerpa L.; Kochzius M.	Contamination, FP-XRF, ICP-MS, Southern Ocean, Trace metals	increased human activity in the Antarctic Peninsula combined with accelerated melting of its glaciers highlights the importance of monitoring trace element concentrations. Surface sediment samples were collected around King George Island, Hope Bay and in the Bransfield Strait in February 2020 and were analysed by X-ray fluorescence spectroscopy and inductively coupled plasma mass spectrometry. The methods display a good correlation. Our results show clear distinctions between these regions for selected elements with high local heterogeneities. Hope Bay exhibited lower concentrations of Fe, Mn, Co, V, Zn while most stations in the Bransfield Strait and around King George Island showed moderate to significant enrichment in Cu, As and Cd. Twelve stations presented a moderate ecological risk. The consistency of our values supports a natural rather than anthropogenic origin, possibly related to volcanism and the geology of the area. However, our results suggest an increase in Cr that should be further investigated.
105					2023	Evidencing Fluid Migration of the Crust during the Seismic Swarm by Using 1D Magnetotelluric Monitoring	Vargas C.A.; Caneva A.; Solano J.M.; Gulisano A.M.; Villalobos J.	Antarctic Peninsula, apparent resistivity, earthquakes, electromagnetic anomalies, magnetotellurics, Orca submarine volcano, Seymour–Marambio Island.	We applied multi–temporal 1D magnetotelluric (MT) surveys to identify space–time anomalies of apparent resistivity ((Formula presented.)) in the upper lithosphere in the Antarctic Peninsula (the border between the Antarctic and the Shetland plates). We used time series over several weeks of the natural Earth’s electric and magnetic fields registered at one MT station of the Universidad Nacional de Colombia (RSUNAL) located at Seymour–Marambio Island, Antarctica. We associated resistivity anomalies with contrasting earthquake activity. Anomalies of (Formula presented.) were detected almost simultaneously with the beginning of a seismic crisis in the Bransfield Strait, south of King George Island (approximately 85.000 events were reported close to the Orca submarine volcano, with focal depths < 20 km and MWW < 6.9). We explained the origin of these anomalies in response to fluid migration near the place of the fractures linked with the seismic swarm, which could promote disturbances of the pore pressure field that reached some hundreds of km away.
106					2024	De novo transcriptome sequencing and annotation of the Antarctic polychaete Microspio moorei (Spionidae) with its characterization of the heat stress-related proteins (HSP, SOD & CAT)	Fonseca-González I.; Velasquez-Agudelo E.; Londoño-Mesa M.H.; Álvarez J.C.	Antarctic invertebrates, Climate change, Heat-stress proteins, Ocean warming, Protein structures, RNA-seq	We present a de novo transcriptome assembly for the non-model Antarctic polychaete worm Microspio moorei (Spionidae) collected during Antarctic field expedition in Fildes Bay, King George Island, Antarctic Peninsula, in 2017. Here, we report the first transcriptome reference array for Microspio spp. The gene sequences of the spionid worm were annotated from a wide range of functions (i.e., biological, and metabolic processes, catalytic processes, and catalytic activity). HSP70, HSP90 SOD and CAT families were compared to reported annelid transcriptomes and proteomes. The phylogenetic analysis using COI, 16S, and 18S markers effectively clusters the species within the family. However, it also casts uncertainty on the monophyletic nature of the Microspio genera, indicating the necessity for additional data and potentially requiring a reevaluation of its grouping. Within these protein families, 3D model software was used to create one representative of their protein structures. Structural predictions were compared with related reported annelids living at different temperatures and a human X-ray reference. We found structural differences (RMSE >1.8) between the human HSP proteins but no significant differences between the polychaete-predicted proteins (RMSE
107					2024	Sex-specific mercury levels in skin samples of southern elephant seals (Mirounga leonina) at Isla 25 de Mayo (King George Island), Antarctic Peninsula	Barragán-Barrera D.C.; Riet-Sapriza F.G.; Mojica-Moncada D.F.; Negrete J.; Curtosi A.; Bustamante P.; Caballero Susana.; Luna-Acosta A.	Antarctica, contamination, elephant seal, heavy metals, Hg, mercury, pinnipeds, South Shetland Islands	The southern elephant seal (SES; Mirounga leonina) has a circumpolar distribution, breeding mainly on sub-Antarctic islands and making long trips between breeding or molting and foraging areas. Most individuals from colonies in the South Shetland Islands (western Antarctic Peninsula; WAP) are distributed in Antarctic Specially Protected Areas (ASPA). Despite these protected habitats, pollutants can reach such remote areas far away from emission sources, affecting local fauna. To assess possible mercury (Hg) contamination in SES, we analyzed skin samples collected from free-ranging molting individuals using the remote biopsy PAXARMS system in Isla 25 de Mayo/King George Island (62°15′S, 58°39′W; ASPA 132). Hairless skin samples were analyzed to determine total-Hg (THg) concentrations, which ranged between 145 ng/g and 1,915 ng/g (M = 730, SD = 388 ng/g), showing significant differences between sexes, with adult-females having higher concentrations (range = 306–1,915, M = 859, SD = 427 ng/g dw) than subadult-males (range = 145–1,645, M = 629, SD = 329 ng/g dw). These differences may be explained mainly by feeding-niche partitioning between sexes. Females prefer mesopelagic prey or prey associated with sea-ice in the WAP, which are enriched in methylmercury. These results provide insight regarding Hg contamination in top Antarctic predators like SES, and the need to monitor for potential effects of Hg contamination in Antarctic marine mammals.
108					2024	Identification of tardigrades from the Half Moon Island, Antarctic	Rosa Acevedo-Barrios, Carolina Rubiano-Labrador, Hernando Altamar Mercado, Jorge Luis Villalba, Andrea Monroy-Licht, Liliana Carranza-López, María Angélica Leal, David Tovar.	Antarctica, biodiversity, occurrence, extreme environment, lichen.	Half Moon Island is one of the Antarctic Islands of South Shetland. With an area of about four-square kilometers, it has some elevated areas such as the Cerro Capa Negra or also called Morenita Hill, which presents rocks of volcanic origin, tonalites type. There are also several species of mosses and lichens, in which the presence of tardigrades was checked. The remarkable ability of tardigrades to withstand a wide range of stressors has sparked a renewed interest in studying their presence in Antarctica. Identification of tardigrades was carried out using optical equipment such as microscope, stereoscope and camera. The following species were found: Diphascon victoriae, Diphascon rudnicki, Hypsibius conwentzii, Hypsibius dujardini, Macrobiotus aradasi, Echiniscus spp. and Hexapodibius spp. These species allowed an analysis of the diversity in Cerro Capa Negra. Further evaluations are needed to better understand the presence of tardigrades in Antarctica.

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