Universidad de Magallanes
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Native avian predators for the world's Black-browed Albatross (Thalassarche melanophrys) breeding colony in inner waters of Tierra del Fuego, Chile
No full textThe breeding season is the most vulnerable period in the early stages of the life cycle of seabirds, due to the exposure of their eggs and chicks to the impact by predators. Most of the studies on predator-prey relationships between the Black-browed albatross (Thalassarche melanophrys) and other predators like raptors, were carried out in breeding colonies located in oceanic and highly isolated areas, such as Antarctic islands. However, breeding colonies located in the Sub-Antarctic fjords have not been studied. The geographical position of the study colony makes it susceptible to a wider spectrum of predators than the oceanic islands. Therefore, it is unknown how predation dynamics affect the reproductive success of this species. Here, we show for the first time the identity and activity of avian native predators on the colony in the inner waters of southern Tierra del Fuego, Chile. This study covered seventeen field visits between 2017 and 2020 to monitor the reproductive activity of this colony. In this study, we identified the interaction between predators, the breeding activity and success of albatrosses using direct census and camera traps. Across the study, the number of breeding pairs ranged from 64 (2017) to three (2019) breeding pairs of the Black-browed albatross. Terrestrial birds with occurrence on the colony were the Andean condor, Southern caracara, Chimango caracara and the Turkey vulture. Our results showed that the main avian predator species affecting the breeding success of the Black-browed albatross, were both the Andean condor and the Southern caracara. The Black-browed albatross is a conservation target in this area since of the colony of Islote Albatros is currently part of the Seno Almirantazgo Marine protected area. Therefore, baseline informations on species interactions are fundamental for its management particularly when native predators like the Andean condor are also threatened species globally
Distribution of dinoflagellate cyst assemblages in surface sediments of Magellan fjords and channels (Patagonia, Chile) with a focus on harmful species: An overview on environmental scenario
No full textSeveral dinoflagellate species form benthic resting cysts in their life cycle. In order to study the composition, abundance and distribution of cyst assemblages, with a focus on harmful species, thirty-one surface sediment samples from the Magellan fjords and channels system were analysed. In situ (temperature, salinity, inorganic nutrients, dissolved oxygen, organic matter, and chlorophyll-a) and five-year (salinity, temperature, dissolved oxygen, and chlorophyll-a) measurement data were analysed to obtain an overview on environmental scenario. A total of 56 cyst morphotypes were recorded, some of which were identified for the first time for the Chilean coast (Dactylodinium cf. arachnoides, Impagidinium cf. velorum, Archaeperidinium sp., Protoperidinium haizhouense, Pro-toperidinium sinuosum, Protoperidinium tricingulatum, and Dubridinium cf. ulsterum). In vitro germination of cysts allowed the vegetative form of the species of the order Suessiales to be determined. Total cyst concentrations were highly variable, ranging from 145 to 5453 cysts mL-1 of wet sediment (mean 1246 +/- 1061 cysts mL-1), with the lowest cyst values in the area adjacent to the Southern Patagonian Ice Field. Pentapharsodinium dalei and Protoperidinium conicoides generally dominated (%) the cyst assemblages. The harmful species Alexandrium cat-enella and Alexandrium ostenfeldii were not abundant and sparsely distributed, while Protoceratium reticulatum was widespread and highly abundant with Gonyaulax spinifera in Inutil Bay (Magellan Strait). Cluster and nMDS analyses performed with cyst concentrations of the 56 taxa in the 31 stations formed seven cyst assemblage clusters, reflecting high environmental variability. Canonical correspondence analyses performed with cyst concentrations and in situ and long-term environmental data showed different ecological signals, demonstrating that in situ parameters must be used carefully when studying cysts in surface sediments
Flora de la Reserva Natural Pingüino Rey (Tierra del Fuego, Chile): criterios y narrativas para la selección de plantas carismáticas
No full textThe King Penguin Nature Reserve (KPNR) in Bahía Inútil (Strait of Magellan, Chile), protects the only King Penguin nesting colony (Aptenodytes patagonicus) that exists in Chile, and represents one of the most visited ecotourism resources in Chilean Tierra del Fuego Island. The vegetation in the area is dominated by the Patagonian steppe, a desert landscape where tiny plants stand out, with showy flowers and whose food, ritual and medicinal use was well known by the hunter-gatherer Selk'nam people. Despite the important milestone that the KPNR represents, the tourist information offered there is restricted to the King penguin, omitting the potential narratives that can be elaborated from the vegetal landscape and ethnographic memory. In this study, the vascular flora of the KPNR was inventoried, and an exhaustive review of scientific literature was carried out to evaluate the potential of this biodiversity in the elaboration of a complementary narrative for ecotourism. On the basis of aesthetic, ecological, distributional, ethnobotanical and historical criteria, 12 of the 85 registered species were selected for the preparation of narratives. In this study, we propose that the selected criteria may be useful to elaborate a story, but the quality of the content will depend on the available scientific research. Also, we suggest that narratives integrating charismatic plants, their ethnobotanical uses, ecological and historical context, can be complementary tools to improve the contents of ecotourism in the KPNR, interpreting the natural history of the area and thus, enrich the visitor's experience for a better knowledge of a heritage until now, undervalued
Holocene hydroclimate variability along the Southern Patagonian margin (Chile) reconstructed from Cueva Chica speleothems
No full textPatagonia is ideally situated to reconstruct past migrations of the southern westerly winds (SWWs) due to its southerly maritime location. The SWWs are an important driver of Southern Ocean upwelling and their strength and latitudinal position changed during the Holocene, leading thus to different responses of the vegetation to past climate changes along the Chilean continental margin. A new speleothem record from Cueva Chica (51 degrees S) is investigated to reconstruct past climatic changes throughout the Holocene in conjunction with other marine and paleoenvironmental records of the region and better constrain the regional paleoclimatic evolutions of SWWs. Samples comprising both a flowstone core and a stalagmite were radiometrically dated (U-Th & 14C) to construct age-depth models for the highly-resolved proxy profiles (delta 13C, delta 18O, chemical composition). The Cueva Chica record provides a highly-resolved isotopic and elemental curves for the last 12 ka, albeit with a hiatus from 5.8 to 4 ka BP. The multi-proxy analysis suggests three climatic regimes throughout the Holocene in Southern Patagonia: i) an early Holocene wet period (with the exception of two dry excursions at 10.5 ka and 8.5 ka BP), ii) a mid-Holocene dry period and iii), a return to generally wet conditions over the late Holocene. The global drivers for these tri-phased climatic regimes are likely related to oceanic and South polar feedbacks. The early Holocene was the warmest period and might be attributable to changes in global ocean circulation which involved a rise in air T degrees and a strength in SWW from 50 degrees S, and therefore higher precipitations over landmass. After 9 ka BP, an intensified deglaciation dynamic along the Antarctic Peninsula is concordant with increasing summer insolation in the Southern hemisphere, leading to a poleward shift of the SWWs in response to global warming and thus to a reduction in moisture supply from the Pacific onto the Patagonian shore. After 5 ka BP, a gradual SST decline is consistent with an equatorward shift of the SWWs in response to a cooling Southern hemisphere. The SWW storm tracks extended to lower latitudes, inducing a return to wetter conditions with highly variable moisture patterns along the Patagonian landmass. Clumped isotope (Delta 47) analyses at lower resolution reflect the degree of kinetic isotope fractionation at the time of carbonate deposition, especially during the dry interval around 8.5-5.5 ka BP. Reduced kinetic isotope fractionation is observed since at least 2.6 ka BP, a period marked by (slightly) wetter conditions
Differential neutralizing antibody responses elicited by CoronaVac and BNT162b2 against SARS-CoV-2 Lambda in Chile (vol 7, pg 524, 2022)
No full textIn the version of this article initially published, an additional affiliation, Millennium Institute on Immunology and Immunotherapy, Santiago, Chile, was not listed for Mónica L. Acevedo, Claudia P. Cortes, Fernando Valiente-Echeverría and Ricardo Soto-Rifo. The error has been corrected in the HTML and PDF versions of the article
Denervation Drives YAP/TAZ Activation in Muscular Fibro/Adipogenic Progenitors
No full textLoss of motoneuron innervation (denervation) is a hallmark of neurodegeneration and aging of the skeletal muscle. Denervation induces fibrosis, a response attributed to the activation and expansion of resident fibro/adipogenic progenitors (FAPs), i.e., multipotent stromal cells with myofibroblast potential. Using in vivo and in silico approaches, we revealed FAPs as a novel cell population that activates the transcriptional coregulators YAP/TAZ in response to skeletal muscle denervation. Here, we found that denervation induces the expression and transcriptional activity of YAP/TAZ in whole muscle lysates. Using the Pdgfra(H2B:EGFP/+) transgenic reporter mice to trace FAPs, we demonstrated that denervation leads to increased YAP expression that accumulates within FAPs nuclei. Consistently, re-analysis of published single-nucleus RNA sequencing (snRNA-seq) data indicates that FAPs from denervated muscles have a higher YAP/TAZ signature level than control FAPs. Thus, our work provides the foundations to address the functional role of YAP/TAZ in FAPs in a neurogenic pathological context, which could be applied to develop novel therapeutic approaches for the treatment of muscle disorders triggered by motoneuron degeneration
Nature-Based Solutions (Nbs) For Addressing Water Scarcity In The Mediterranean Ecoregion Of Chile Soluciones De Base Natural (Sbn) Para Conflictos De Escasez Hídrica En La Ecorregión Mediterránea De Chile
No full textNatural-based Solutions (NbS) allow us to face socio-environmental challenges and risks through the protection, restoration and sustainable management of ecosystems, provi-ding human well-being and increasing biodiversity. In the last decade, the Mediterranean Ecoregion of Chile (EMC, 29-37ºS) has experienced a continuous drought and numerous water conflicts associated with the development of industrial activities in areas that pro-vide ecosystem services of water supply and regulation. In this context, the use of NBS in water scarcity conflicts in the CME was evaluated as a way to support the design of public policies that incorporate this approach. For this, conflicts associated with water scarcity in the CME were collected and NBS were identified to face similar conflicts in other regions of the world. Three categories of NBS were identified: (i) watershed restoration and green infrastructure, (ii) ancestral and natural infrastructure, and (iii) integrated agricultural practices. This analysis indicates that the simultaneous use of these three strategies can contribute to the resolution of water conflicts in CME. NBS are projected as an efficient and integrating option to face the problems of water scarcity, since they are considered within national policies and designed according to the environmental conditions and social context of each sector in conflict
Isotope geochemistry as a natural tag of fish in Patagonian freshwater environments: The invasive Chinook salmon case
No full textPatagonian aquatic environments have been invaded since the end of the last century by different species of salmonids. Knowing the natal origin and homing/straying rate of the salmonids in colonised environments is essential to under-standing the dispersal mechanisms and developing management plans. In the last two decades, Chinook salmon Oncorhynchus tshawytscha showed the greatest natural dispersal capacity in Patagonia. The main goal of this study was to evaluate the environmental strontium isotope ratio (87Sr/86Sr) as a potential natural tag to infer the natal origin and ontogenetic habitat use of salmonids in Patagonia, specifically Chinook salmon. 87Sr/86Sr ratio was determined in water samples from 26 sites distributed in 14 Atlantic and Pacific basins in low and high water seasons. Environmental 87Sr/86Sr showed greater spatial than temporal variation, revealing great potential as a tool to infer the natal origin and life history of several migratory fish species in Patagonia. Otolith core-to-edge 87Sr/86Sr profiles were also analysed in 108 Chinook salmon from six basins. A cluster analysis based on the Unweighted Pair Group method (UPGMA) and Euclidean distances without prior classification grouped the sampled rivers into five main groups with significantly dif-ferent (p < 0.05) isotopic ratios, sometimes integrated basins with different slopes (Atlantic or Pacific). The cluster analysis based on the natal 87Sr/86Sr period in otolith (similar to natal origin) showed clear segregation between the Atlantic and Pacific samples. A mismatch between water and otolith natal 87Sr/86Sr ratio was detected in some Atlantic basins (e.g. De las Vueltas River in Santa Cruz Basin) and Pacific (e.g. Liquine Basin) and, which could be explained either by straying behaviours or by large geochemical variability between tributaries, within river systems. Our results showed that 87Sr/86Sr is a useful natural tag to trace the life history of migratory fishes in Patagonia, especially for in-vasive species such as Chinook salmon
Una propuesta para el desarrollo del turismo cultural en Tierra del Fuego
No full textLa ex Fábrica de Cal de Porvenir, establecida por el croata Natalio Foretich a principio de siglo XX en Tierra del Fuego, constituye el único vestigio de la actividad industrial asociada a la producción de cal en el territorio. Situada a orillas de la bahía, su actual vacancia y frágil estado de conservación contrasta drásticamente con su ostensible valor patrimonial y con las aspiraciones turísticas de la comuna. En consecuencia, el presente trabajo presenta los lineamientos generales de un proyecto de arquitectura desarrollado en el contexto de un ejercicio académico conducente a la obtención de grado, orientado a la rehabilitación del inmueble y su inserción como nuevo Centro de Interpretación en un circuito turístico que contribuya al avance del turismo cultural de la zona, promoviendo, al mismo tiempo, el uso social de un patrimonio local
Going up the Andes: patterns and drivers of non-native plant invasions across latitudinal and elevational gradients
No full textThe Andes mountain range in South America has a high level of endemism and is a major source of ecosystem services. The Andes is increasingly threatened by anthropogenic disturbances that have allowed the establishment of non-native plants, mainly in the lower elevation areas. However, synergies between climate change and anthropogenic pressure are promoting the spread of non-native plants to higher elevation areas. In this article, we evaluate and identify the main non-native plants invading Andean ecosystems, and assess their taxonomic families, growth forms and distribution patterns. Based on a systematic literature review, we identified the importance of climatic and anthropogenic factors as drivers of non-native species establishment in Andean ecosystems and the main impacts of non-native plants in the Andes. We then identified research gaps across each biogeographic region in the Andes. Finally, we highlight key elements to better tackle the problem of non-native plant invasions in Andean ecosystems, including the need for a systematic monitoring of invasion patterns and spread (e.g. MIREN protocol) and a common policy agenda across international borders for the prevention and management of non-native plants in this highly vulnerable region