Magallanes Region Research Articles

Livestock guarding dogs shape activity patterns of sympatric mesocarnivores in sheep ranches of the Patagonia region

Predation of livestock by wild carnivores is a source of human-wildlife conflict. Livestock Guarding Dogs (LGDs) are one of the most effective non-lethal methods used. LGDs could impact wildlife due to their possible top predator role; their effect on mesocarnivores has been studied mainly in terms of space use, however, temporal effects may also exist. Our study sought to determine the possible effects of LGD presence on the activity patterns of the native foxes Lycalopex griseus and L. culpaeus in southern Chile. Activity patterns were estimated from fox detections with camera traps set on ranches with and without LGDs in Isla Riesco, Magallanes region, Chile, between 2016 and 2018. We quantified the activity patterns of each fox species in presence/absence of LGDs, and under different conditions including breeding vs non-breeding season, moon phase and vegetation cover. Both species modified their daily activity pattern, avoiding times of day of high LGD activity; nevertheless, these modifications did not change the temporal interaction between the native foxes. Activity patterns of foxes without LGDs did not differ from those in natural areas. The effect of LGDs on fox activity patterns was stronger than other ecological variables (breeding season, moon phase or vegetation cover). Since LGDs change the activity patterns of foxes, they cannot be seen as a totally innocuous predation control tool; however, carnivores’ temporal avoidance of areas with a fear-evoking agent like LGDs would result in fewer livestock-predators encounters, thus reducing sheep predation risk. LGDs appear to exert non-lethal effects upon carnivores that would contribute to reduced predation rates and may help decrease producers’ economic losses, as well as the retaliatory hunting of wild carnivores. Thus, our results support that LGDs could be contributing to the co-existence with native predators in areas destined for livestock production.

Optimizing culture medium to facilitate rapid Renibacterium salmoninarum growth

This study presents significant improvements in the culturing of Renibacterium salmoninarum, the causative agent of bacterial kidney disease (BKD) in salmonids. Our goal was to improve R. salmoninarum cultivation and its detection in salmon farming by adjusting to 1.5%wv−1 NaCl into kidney disease medium-2 (KDM2), which significantly expedited growth without further effects from varying NaCl concentrations. The reductions in incubation periods of cultivation, this approach enhances early and accurate bacterial and disease surveillance, enabling prompt intervention. The modified medium significantly accelerated R. salmoninarum growth, achieving an optical density at 600 nm of 0.5 within 5–6 days post-incubation, marking a notable improvement over traditional KDM2. Exploring a range of NaCl concentrations in solid and liquid media revealed distinct growth patterns of R. salmoninarum across various strains. Among these, 1.5%wv−1 NaCl proved highly effective in promoting rapid pathogen proliferation while preserving essential components roles in the medium, with an average of 75% of reduction in incubation times in plate agar culture media. Strains isolated from salmon organs in the Los Lagos and Magallanes region exhibited high pathogenicity, leading to 80–100% mortality within 30 days, underscoring the wide-ranging efficacy of NaCl in enhancing growth, irrespective of geographic origins. Moreover, the modified media, enriched with NaCl, demonstrated no compromise in the pathogenicity of R. salmoninarum strains. These results highlight the potential of NaCl supplementation, supporting its addition in the media of R. salmoninarum. This inclusion could expedite biomass growth within shortened timeframes, stimulate microbial aggregates, and enhance bacterial multiplication within the medium. These findings affirm the utility of KDM2-NaCl in enhancing R. salmoninarum effective cultivation and detection, offering cost-effective strategies for managing infections and supporting targeted interventions in the salmon industry.

On the distribution and habitat use of the sub-Antarctic fly Hyadesimyia clausa Bigot (Diptera, Tachinidae) according to citizen science.

Hyadesimyia clausa Bigot is a morphologically striking tachinid that inhabits the Sub-Antarctic Ecoregion of the Magallanes Region in Chile and Tierra del Fuego province in Argentina. Much of the distributional information about this species is restricted to the Cape Horn islands, which have extreme environmental conditions, but the species' natural history, range limits, and habitat use have never been described or confirmed. Our goals were to describe the distributional limits of this sub-Antarctic fly with the help of citizen science and use this information type to describe this tachinid's habitat use and potential biological interactions with nonvascular and vascular flora. We found that citizen science significantly increased our understanding of the extent of occurrence, expanding the known distributional range by 195 km to the north and 153 km to the west. On the contrary, the values for the area of occupancy were not significant, but the occupancy overlap between different records was very low. We confirmed that H. clausa's habitat uses peatlands and although we have not provided evidence of pollination or movement of spores, we hypothesized, that the walking activity of H. clausa could help move sperm from mosses and pollen from the flowers of vascular plants, so they could act as potential pollinators. Citizen science can reduce and eliminate some scientific knowledge shortfalls and propose new ecological questions that could increase our knowledge of extreme ecosystems.

A unique Late Cretaceous fossil wood assemblage from Chilean Patagonia provides clues to a high‐latitude continental environment

AbstractFossil plants, including large trunks, stems, some branches, and twigs, were collected from the Maastrichtian (68.9 Ma), upper Dorotea Formation in the Magallanes–Austral Basin, 16 km north of the Cerro Guido–Las Chinas complex in the southern Chilean Magallanes region. These fossil trunks range from 0.2 to 2.2 m in length. Petrographic slides were made in three sections (transverse, radial and tangential) and analysed under a light microscope to study the permineralized fossils. The woods and stems belong to Austroginkgoxylon gen. et sp. nov., Agathoxylon antarcticum, Podocarpoxylon paradoxi sp. nov., Podocarpoxylon mazzonii, Palmoxylon subantarcticae and Notomalvaceoxylon magallanense gen. et sp. nov. The growth rings of gymnosperms and anatomical characters of angiosperms were analysed to obtain palaeoecological data. Interactions between gymnosperm roots growing into the secondary xylem of an angiosperm (nurse logs) are recorded. The data obtained from the fossil woods suggest warm and humid conditions in this southern South American locality during the Late Cretaceous, providing a unique opportunity to study continental environments at high southern latitudes, which are poorly represented on a global scale.

Causal analysis of escapement of farmed salmonids in southern Chile

Escaped salmonids are considered among the most serious threats to the aquatic environment. One hundred and nine escape incidents were reported in Chile from 2004-2021, representing some 8.53 million escaped salmonids. Of this total, 5.73 million were Atlantic salmon Salmo salar (67.2%), 0.83 million coho salmon Oncorhynchus kisutch (9.8%), and 1.96 million were rainbow trout O. mykiss (23.0%). It is estimated that 70.1% of the escaped salmonids were recorded in the Los Lagos Region, 23% in the Aysén Region, and 4.6% in the Magallanes Region. In total, 80.5% of the escapes were recorded from seawater facilities, while freshwater units accounted for 19.5%. The highest percentage of escaped salmon recorded in seawater over 2004-2021 was 1.71% of harvested salmonids in 2013. Some 39.5% of the escapes in 2015-2021 were attributed to rupturing of net cages, mainly due to adverse climatic conditions. The additional regulations introduced in 2020 by the Chilean authority, has helped to minimize the escape of farmed salmonids. As a consequence, just one escape event was reported in 2021, corresponding to 3.85% of the total number of escapees recorded from 2004-2021.

Sporotrichosis Outbreak Due to Sporothrix brasiliensis in Domestic Cats in Magallanes, Chile: A One-Health-Approach Study

To describe a S. brasiliensis outbreak in domestic and feral cats detected in the Magallanes region of southern Chile. Between the months of July and September 2022, three cats presented with suppurative subcutaneous lesions located mainly on the head and thoracic limbs. The cytology revealed the presence of yeasts with morphological characteristics suggestive of Sporothrix spp. The histopathology confirmed pyogranulomatous subcutaneous lesions associated with the presence of the same yeasts. The fungal culture followed by the partial gene sequence and analysis of the ITS region confirmed the diagnosis of the S. brasiliensis as the causative agent. The cats were treated with itraconazole associated in one case with potassium iodide. The evolution of the patients was favorable in all cases. An outbreak caused by S. brasiliensis was detected in domestic and feral cats in austral Chile. The correct identification of this fungus and antifungigram is essential for treatment decisions and for designing dissemination control and prevention programs under a one health approach that consider the health of people, animals, and the environment.

Historical ecology and current abundance of the translocated Chilla or Grey fox Lycalopex griseus on the large Tierra del Fuego Island shared by Argentina and Chile

AbstractIn 1951, a batch of 24 young animals of both sexes of Chilla or Grey fox Lycalopex griseus from continental Magallanes region, Chile – and perhaps also from adjacent continental Argentina – were released at Onaisin (65 km ESE Porvenir town, 53°18′S) on Tierra del Fuego Island in southernmost South America, to control a European rabbit (Oryctolagus cuniculus) irruption that was considered detrimental to sheep (Ovis aries) ranching. Up to now, no attention has been paid to the temporal course of that introduction. Here we provide a historical account of the presence of foxes on the Tierra del Fuego Archipelago, starting with Charles Darwin account of 1839 until present. We also review the regulatory framework concerning hunting of those foxes and tally their culling for export of pelts. Finally, we provide estimates of the abundance of Chilla foxes on Tierra del Fuego Island for the period 1999–2007 and for 2021, and highlight their current spread. These translocated foxes have become an abundant and functional part of both steppe and forest ecosystems on the Fuegian archipelago, even though they are killed by hunters, without spatial, temporal, or numerical limits. We conclude that interesting scientific opportunities are being missed regarding the population genetics of a species that may have left founding effects and genetic bottlenecks in Tierra del Fuego, and perhaps some peculiar continental markers among the island population. We also raise the question whether this introduced native species may be deemed invasive, calling for research to determine its impact in its new environment.

On the presence of Aegorhinus nodipennis (Hope, 1834) (Coleoptera: Curculionidae) in Magallanes Region, Chile

The presence of the weevil Aegorhinus nodipennis (Hope, 1834) in Magallanes Region, Chile is reported for the first time. The significance of the record as well as its relationship with the recent interception on Argentinean Tierra del Fuego is discussed.

A bug’s tale: revealing the history, biogeography and ecological patterns of 500 years of insect invasions

The arrival of Europeans to the Americas triggered a massive exchange of organisms on a continental scale. This exchange was accelerated by the rapid increase in the movement of people and goods during the 20th century. In Chile, scientific and technical literature contains hundreds of records of non-native insect species established in different parts of the territory, from the hyperarid Atacama Desert to the Magallanes Region. Here, we analyse temporal trends, taxonomic diversity, biogeographic origin and main impacts of these species on different sectors in Chile from the European arrival to the present. Our task includes a review of old records in museum catalogues, libraries, collections, expedition records and catalogues. Almost 600 species of non-native insects have been reported to be established in Chile. Introductions started with the very arrival of Europeans to the central valley of Chile and underwent a huge acceleration in the second half of the 20th century. The order Hemiptera was the most prevalent amongst non-native insects. Most species are linked to agriculture and forestry. Species are of Palearctic origin in more than 50% of the records. In terms of temporal trends, the rate of established non-native species shows an abrupt increase at the beginning of the 1950s. This change may be associated with the strong development in agriculture and forestry in Chile after World War II and the increase in intercontinental air traffic. We believe that the understanding of past patterns of introductions is an important component in the design of current policies to minimise the impact of invasive insects.

The role of the huemul (Hippocamelus bisulcus) in Patagonian maritime hunter-gatherer strategies: The case of Diego Portales Island and Última Esperanza inland sea (Chile)

The biodiversity of animal species in the Última Esperanza inland sea (Magallanes region, Chile) provides an exceptional opportunity to study the economic and organizational strategies of maritime hunter-gatherer groups in the Fuego-Patagonian archipelago. The consumption of huemul (Hippocamelus bisulcus) in Southern South America is well documented since the Middle Holocene, although its role in the subsistence strategies of maritime hunter-gatherers varies depending on the geographical and environmental area. The aim of this paper is to assess the implications of huemul exploitation on organizational strategies by Late Holocene maritime hunter-gatherer groups from the Última Esperanza inland sea (Magallanes region, Chile). In this work we present the results of a zooarchaeological analysis of the huemul assemblage from the sites of Bahía Easter 1 and Bahía Easter 2 (Diego Portales Island, Última Esperanza, Chile). The results show the high importance of huemul in the maritime hunter-gatherer diet, and provide new insights into the hunting and transport strategies of this prey. Furthermore, the integration of the data within the local and regional archaeological record allowed us to identify similarities at the scale of the inland sea, where huemul was frequently exploited both in island and coastal environments in contrast to what is documented in the neighboring Skyring Sea and Otway Sea.

Distribution of phycotoxins in Última Esperanza Province during the PROFAN expedition 2019

Harmful Algae Blooms pose an increasing threat to the public health and economic stability of Southern Chile, particularly to the aquaculture industries. This fieldwork performed during the PROFAN expedition from 12th to 22nd November 2019 extends the knowledge on the distribution of marine toxin-producing species in the difficult to access Última Esperanza Province in the Magallanes Region. Paralytic Shellfish Poisoning toxins with high relative abundances of saxitoxin and lipophilic toxins dominated by yessotoxins, pectenotoxins and domoic acid were detected at nearly each sampling station. The respective toxin-producing organisms are mainly from the genus Alexandrium and Dinophysis. Furthermore, the first detection of pinnatoxin-G (PnTx-G) in Chilean waters strongly indicates the presence of the dinoflagellate Vulcanodinium rugosum.

Functional characterization of patients with cerebral palsy living in the Magallanes region and the Chilean Antarctic

To functionally characterize patients with Cerebral Palsy (CP) living in the Magallanes Re gion and the Chilean Antarctic. Descriptive-retrospective observational study of patients with cerebral palsy, registered in the Outpatient Rehabilitation Program of the Corporación de Rehabilitación Club de Leones Cruz del Sur de Punta Arenas between 1986 and 2018. Patients with CP were clinically categorized and then functionally characterized according to gross motor skills (GMFCS), manual ability (MACS), feeding ability (EDACS), and communication function (CFCS). 106 patients were included. Regarding the clinical classification, the most common type of CP was bilateral spastic paralysis, with the highest percentage of functional involvement in each of the evaluated areas, followed by unilateral spastic paralysis, while cases of dystonic CP and other non-classifiable types presented were less frequent. According to the clinical subclassification, spastic diplegia was more frequent, especially affecting manual and communication skills level I compared with hemiplegia, while cases of mixed and unclassifiable quadriplegia were less frequent with greater overall involvement of level I feeding skills. The observed results of CP in the Magalla nes Region and the Chilean Antarctic are similar to studies available in the literature. The complete evaluation and classification of patients with CP enable a better understanding of the pathology for future studies.

Association of Physical Fitness, Screen Time, and Sleep Hygiene According to the Waist-to-Height Ratio in Children and Adolescents from the Extreme South of Chile.

Objective: To analyze the perception of physical fitness, screen time, and self-reported sleep hygiene in children and adolescents (CA) from the extreme south of Chile and its associations with waist-to-height ratio (WtHr). Material and methods: An observational cross-sectional study was conducted in a sample of 594 schoolchildren from 5th to 8th grade of primary education, belonging to municipal educational establishments in the Magallanes region, Chile. Cardiorespiratory fitness was assessed through the 20-m shuttle run test, muscle strength through handgrip and the standing broad jump test, physical fitness perception through the International Fitness Scale, and central obesity through the waist-to-height index. In addition, sleep hygiene and screen time were measured. Results: More than 92% of CA spent more than two hours a day watching or using screens. In addition, CA with excess central adiposity had a lower perception of physical fitness, and lower muscle strength and cardiorespiratory fitness compared to CA with normal values of adiposity. Conclusions: CA of the present study spent a high number of hours watching or using screens and had poor sleep quality. In addition, excessive central adiposity was associated with lower physical fitness.

Participação ocupacional e inclusão social da comunidade LGBTIQ+ na região de Magalhães e Antártica Chilena

Abstract Introduction People of sexual diversity have been violated in their human rights and marginalized from participating in some spaces, and occupations as a result of prejudices and social constructions that have been imposed as the predominant culture throughout history. Objective To know the perception of people from the LGBTIQ+ community, about their social inclusion and occupational participation in the different spaces of daily life in the Magallanes and Chilean Antarctica region. Method Semi-structured interviews were applied to LGBTIQ+ people between 20 and 40 years old, the stories were interpreted through content analysis, using qualitative methodology with a descriptive approach. Results Different opinions are obtained about the occupational participation of LGBTIQ+ people, pointing out some positive experiences of acceptance, however, experiences of discrimination and violence predominate, as well as situations of injustice or occupational deprivation as a result of prejudices and beliefs, both social and personal (occupational awareness), According to the reports, needs and proposals are collected to achieve occupational participation and full inclusion. Conclusion The occupational participation and social inclusion of the LGBTIQ+ community are affected by discrimination, prejudice, and beliefs of people in the Magallanes region, showing that progress is still required, and generate spaces for training and re-education related to sexual and gender diversity, deconstructing the prejudices and beliefs that persist in the region.

Molecular Detection of Echinococcus granulosus Sensu Stricto in Environmental Dog Faecal Samples from the Magallanes Region, Patagonia, Chile

Echinococcus granulosus is endemic in the Magallanes region and other areas of Chile. After a successful control programme implemented between 1979 and 2004, dogs’ prevalence decreased from 70% to 0.5%. Since the end of the programme, no prevalence study of canine echinococcosis has been performed in this region. Dog faecal samples were collected from epidemiological units for DNA isolation and polymerase chain reaction (PCR) to detect E. granulosus. In addition, dog owners were required to answer a questionnaire for a risk factor analysis. We collected 1069 environmental dog faecal samples from 267 urban, 241 periurban, and 61 rural epidemiological units. E. granulosus was found in 11/61 (18%) and 1/241 (0.4%) epidemiological units from rural and periurban areas, respectively. The Ultima Esperanza province showed the highest prevalence with eight out of 16 units with faeces positive to E. granulosus showing a main spatial cluster of canine echinococcosis. None of the risk factors investigated showed a statistical significance with positive units. This study shows the active transmission of the parasite in the Magallanes region, especially in the Ultima Esperanza province, with a possible re-emergence of the parasite. Further studies focusing on the incidence in humans are required together with the reestablishment of the compulsory deworming of dogs.

Toxic Alexandrium catenella expanding northward along the Chilean coast: New risk of paralytic shellfish poisoning off the Bío-Bío region (36° S)

In Chile, the toxic dinoflagellate A. catenella shows an apparent oceanic range expansion from south to the north since its first detection in 1972 in the Magallanes Region (56° S). Until 2017, A. catenella detections were restricted to a geographic area between Magallanes to Los Rios Regions (40° S). The establishment of a monitoring program in the offshore Pacific coast allowed the detection of A. catenella between 2018 and 2019 in northern areas off the Bío-Bío Region (36°S). Monoclonal cultures established from the Bío-Bío coast were genetically identified, and PSTs screened. Phylogenetic analyses determined that the Bío-Bío isolates aggregated in Group I ribotype (previously A. tamarense or A. fundyense) and the presence of PSTs analogs were confirmed. It is the northernmost detection of the toxic dinoflagellate A. catenella in the Pacific coast of Chile. These results have important implications for species monitoring and governmental management in the Bío-Bío Region.

Mutation in a SARS-CoV-2 Haplotype from Sub-Antarctic Chile Reveals New Insights into the Spike's Dynamics.

The emergence of SARS-CoV-2 variants, as observed with the D614G spike protein mutant and, more recently, with B.1.1.7 (501Y.V1), B.1.351 (501Y.V2) and B.1.1.28.1 (P.1) lineages, represent a continuous threat and might lead to strains of higher infectivity and/or virulence. We report on the occurrence of a SARS-CoV-2 haplotype with nine mutations including D614G/T307I double-mutation of the spike. This variant expanded and completely replaced previous lineages within a short period in the subantarctic Magallanes Region, southern Chile. The rapid lineage shift was accompanied by a significant increase of cases, resulting in one of the highest incidence rates worldwide. Comparative coarse-grained molecular dynamic simulations indicated that T307I and D614G belong to a previously unrecognized dynamic domain, interfering with the mobility of the receptor binding domain of the spike. The T307I mutation showed a synergistic effect with the D614G. Continuous surveillance of new mutations and molecular analyses of such variations are important tools to understand the molecular mechanisms defining infectivity and virulence of current and future SARS-CoV-2 strains.

Paleogeography and biogeography of the Gondwanan final breakup and its terrestrial vertebrates: New insights from southern South America and the “double Noah's Ark” Antarctic Peninsula

The Mesozoic plate tectonic and paleogeographic history of the final break up of West Gondwana had a profound effect on the distribution of terrestrial vertebrates in South America. As the supercontinent fragmented into a series of large landmasses (South America, Antarctica, Australia, New Zealand, the Indian subcontinent, and Madagascar), particularly during the Late Jurassic and Cretaceous, its terrestrial vertebrates became progressively isolated, evolving into unique faunal assemblages. The episodic nature of South American mammalian Cenozoic faunas became apparent in its modern formulation after George Gaylord Simpson's seminal works on this topic. Two aspects add complexity to this generally accepted scheme: first, the fact that South America is not (and was not) a biogeographic unit, as the Neotropical Region does not include its southernmost tip (the Andean Region, including Patagonia and the southern Andes). Second, and intimately linked with the first one, that South America was not an island continent during the Late Cretaceous and the beginning of the Cenozoic, being its southernmost portion closely linked with West Antarctica up to the late Paleocene at least. Here we stress on this second aspect; we summarize a series of recent, detailed paleogeographical analyses of the continental breakup between Patagonia (including the Magallanes Region) and the Antarctic Peninsula crustal block, beginning with the opening of the Atlantic Ocean in the Early Cretaceous and running up to the Early Paleogene with the expansion of the Scotia Basin. In second place, we comment on the implications of these distinct paleogeographic and paleobiogeographic scenarios (before and after their geographic and faunistic isolation) for the evolution of South American terrestrial mammalian faunas. Summarizing, (1) we recognize a West Weddellian terrestrial biogeographic unit with the assemblage of the southern part of South America (Patagonia and the Magallanes Region) and the Antarctic Peninsula (and probably Thurston Island) crustal block of West Antarctica, spanning from the Late Cretaceous (Campanian) through the Early Paleogene (Paleocene); (2) we suggest that the Antarctic Peninsula acted as a double "Noah's Ark” regarding, first, the probable migration of some non-therian lineages into southern South America; later, the migration of metatherians to Australasia.

New araphid species of the genus Pseudostaurosira (Bacillariophyceae) from southern Patagonia

ABSTRACT We describe five new araphid diatom species belonging to the genus Pseudostaurosira. These new taxa were found in modern and fossil material collected from five southern Patagonian waterbodies (49–52°S), four from the Santa Cruz province, Argentina and one from the Magallanes Region, Chile. When observed under light and scanning electron microscopy, each species differs by a single or a combination of valve character(s). Pseudostaurosira australopatagonica sp. nov. has unique volae that are profusely, dichotomously branched, internally anastomosed, and affixed to the virgae. Pseudostaurosira hyalopatagonica sp. nov. has fusiform valves with cuneate, elongate ends, narrow valves and round to slightly elliptical areolae. Pseudostaurosira catalinae sp. nov. has broadly fusiform valves with cuneate to subrostrate ends; volae form a circular to elliptical ring at the centre of the areolar opening and, externally covering the mantle areolae, it has a watch glass-like flap. Pseudostaurosira tehuelcheana sp. nov. has lanceolate valves with broadly rounded apices, solid incipient conical spines and marginal, transapically elongate areolae occluded by profusely branched volae. Pseudostaurosira zolitschkae sp. nov. is a relatively large-valve species with subrostrate apices, hollow spines, marginal areolae sometimes separated by a thin vimen. The volae in this latter, new taxon, only originate from a position parallel to the transapical axis of the valve, an origin that is uncommon within the genus. We discuss the validity of describing species based on morphological data and highlight the importance of increasing taxonomic resolution on isolated regions such as Patagonia.

Depopulation and rural shrinkage in Subantarctic Biosphere Reserves: envisioning re-territorialization by young people

Landscape-scale conservation at the regional level is an important challenge for Biosphere Reserves (BRs), especially those located in areas suffering from depopulation and rural shrinkage. This is the case of the BRs of the southernmost part of Chile, in the Magallanes region. An analysis of the implications of deterritorialization (the radical reduction or disappearance of inhabitants, their traditional ecological practices, and their material and affective links with the territory) is lacking in the literature, particularly in relation to the migration of young people towards other human settlements. This is a critical situation for BRs because there is a tight link between depopulation and the sustainability of socio-ecological systems. Here we discuss, on the one hand, the limitations and negative impacts of repopulation attempts by extractive industries and, on the other, the possibilities of involving rural youth in initiatives that encourage the re-territorialization of ecological practices and knowledge that have been developed by generations of local inhabitants, as a way of promoting bioculturally sustainable modes of re-inhabiting these territories.