Marcelo Gonzalez

Instituto Antartico Chileno | INACH · Departamento Científico

From December 2023 to March 2024, a surveillance program aiming to detect Highly Pathogenic Avian Influenza (HPAI) H5N1 was conducted on Antarctica territories, specifically at Fildes Peninsula (King George Island, Maritime Antarctic), and James Ross Island. At Fildes Peninsula, samples from marine birds and mammals were collected from four accessi...

Although Antarctica is the most isolated continent on Earth, its remote location does not protect it from the impacts of human activities. Antarctic metazoans such as filter-feeding invertebrates are a crucial component of the Antarctic benthos. They play a key role in the benthic-pelagic carbon flux in coastal areas by filtering particles and plan...

From December 2023 to March 2024, a surveillance program to detect HPAI H5N1 was performed on Antarctica Territory, at Fildes Peninsula (King George Island, Maritime Antarctic), and James Ross Island. At Fildes Peninsula, samples from marine birds and mammals from four sampling locations were collected, based on their accessibility and the presence...

Before December 2020, Antarctica had remained free of COVID-19 cases. The main concern during the pandemic was the limited health facilities available at Antarctic stations to deal with the disease as well as the potential impact of SARS-CoV-2 on Antarctic wildlife through reverse zoonosis. In December 2020, 60 cases emerged in Chilean Antarctic st...

It is generally acknowledged that microplastic pollutants are prevalent in ocean waters and sediments across a range of tropical, temperate, subpolar, and polar regions. The waters surrounding King George Island are significantly impacted by human activities, particularly those related to scientific stations, fishing, and tourism. Organisms, such a...

Environmental conservation requires identification of biological and ecological values, application of protection measures and, thereafter, regular and periodic sampling. The protection of Antarctic values is important for the conservation of the Antarctic environment. In Antarctica, multiple sites with unique values are provided with protection as...

Before December 2020, Antarctica had remained free of Covid-19 cases. The main concern during the pandemic was the limited health facilities available at Antarctic stations to deal with the disease, as well as the potential impact of SARS-CoV-2 on Antarctic wildlife through reverse zoonosis. In December 2020, 60 cases emerged in Chilean Antarctic s...

TThe filter feeder clam Laternula elliptica is a key species in the Antarctic ecosystem. As a stenothermal benthic species, it has a poor capacity for adaptation to small temperature variations. Despite their ecological importance and sensitivity to climate change, studies on their microbiomes are lacking. The goal of this study was to characterize...

Cryobacterium spp. are Gram-positive bacteria that inhabit diverse geographical locations, particularly extremely cold environments like the Polar Regions. However, strategies that enable them to survive in harsh Antarctic environments are not fully understood. In this study, we conducted a comparative genomic analysis of the Antarctic Cryobacteriu...

In understanding stress response mechanisms in fungi, cold stress has received less attention than heat stress. However, cold stress has shown its importance in various research fields. The following study examined the cold stress response of six Pseudogymnoascus spp. isolated from various biogeographical regions through a proteomic approach. In to...

The Antarctic toothfish (Dissostichus mawsoni) is the largest notothenioid species in the Southern Ocean, playing a keystone role in the trophic web as a food source for marine mammals and a top predator in deep-sea ecosystems. Most ecological knowledge on this species relies on samples from areas where direct fishing is allowed, whereas in areas c...

The changes implemented in 2005 in the development strategies of Antarctic science carried out by Chile have had a positive impact on the scientific productivity of the Chilean Antarctic Science Program (PROCIEN). We analysed scientometric indicators from between 2009 and 2019. The bibliographic data were extracted from the Web of Science database...

When an organism makes a long-distance transition to a new habitat, the associated environmental change is often marked and requires physiological plasticity of larvae, juveniles, or other migrant stages. Exposing shallow-water marine bivalves (Aequiyoldia cf. eightsii) from southern South America (SSA) and the West Antarctic Peninsula (WAP) to cha...

Most life forms on earth, including the cold-adapted bacteria from the polar regions, are being affected by global warming. To better understand how global warming may affect Antarctic bacteria, the heat-stress response of cold-adapted Cryobacterium sp. SO1 at the transcript level was determined in this study. A Cryobacterium sp. SO1 culture was gr...

Deception Island is well-known for harboring highly diverse microbial communities due to its unique volcanic environment in Antarctica. Most studies focused on bacteria, and relatively little was known about the fungal species on this island. The present study was aimed to determine the antimicrobial production and nutrient utilization profiles of...

A novel strain of Cryobacterium designated as SO2, was isolated from the Antarctic. Hence, this study was undertaken to gain further insight into the antimicrobial compounds and secondary metabolites produced by Cryobacterium sp. SO2. It was found that strain SO2 is a Gram-positive that exhibits an irregular rod shape, which formed yellow to orange...

Las nuevas tecnologías de secuenciación del ADN han permitido incrementar nuestro conocimiento de las comunidades de microorganismos que interactúan con su respectivo huésped. El equilibrio entre las comunidades bacterianas del huésped puede ser alterado por factores externos como los estresores ambientales. Muchos de los organismos antárticos que...

While diversity studies and screening for enzyme activities are important elements of understanding fungal roles in the soil ecosystem, extracting and purifying the target enzyme from the fungal cellular system is also required to characterize the enzyme. This is, in particular, necessary before developing the enzyme for industrial-scale production...

Plastic pollution represents an emerging environmental issue in terrestrial Antarctica, especially in the Antarctic Peninsula and Maritime Antarctica, which have been recently recognized as hot spots for plastic litter. In these regions, freshwater (FW) environments such as lakes host isolated ecosystems and species that can be severely affected by...

The occurrence and impact of contaminants of emerging concerns (CECs) have been investigated in Antarctica much less than in other parts of the world. Although legacy anthropogenic pollutants can reach Antarctica via long-range transport, CECs mainly originate from local sources. Here, we investigated the ability of a freshwater crustacean, the Ant...

The sponge microbiome, especially in Low Microbial Abundance (LMA) species, is expected to be influenced by the local environment; however, contrasting results exist with evidence showing that host specificity is also important, hence suggesting that the microbiome is influenced by host-specific and environmental factors. Despite sponges being impo...

The Western Antarctic Peninsula (WAP) is among the areas of the planet showing some of the most significant increases in air and water temperature. It is projected that increasing temperature will modulate coastal ecosystems at species ecological performance and molecular composition. The main way that the organisms can cope with large thermal vari...

Thirteen out of the 15 known Cryobacterium spp. were from extremely cold environments. However, the fundamental question on their cold adaptation strategies to survive in the cold has not been addressed adequately. Hence, this work was conducted to determine the Cryobacterium sp. SO1 cold adaptation strategies. Cryobacterium sp. SO1 that grew optim...

Members of the Picornaviridae family comprise a significant burden on the poultry industry, causing diseases such as gastroenteritis and hepatitis. However, with the advent of metagenomics, a number of picornaviruses have now been revealed in apparently healthy wild birds. In this study, we identified four novel viruses belonging to the family Pico...

Introduction: Embryonic and larval development in sea urchins is highly dependent on maternal nutritional status and on the environmental conditions of the seawater. Objective: To compare the development of Arbacia dufresnii in two different water temperatures and in progeny with varying maternal origins. Methods: We induced A. dufresnii females...

Members of the Picornaviridae comprise a significant burden on the poultry industry, causing diseases such as gastroenteritis and hepatitis. However, with the advent of metagenomics, a number of picornaviruses have now been revealed in apparently healthy wild birds. In this study, we identified four novel viruses belonging to the family Picornaviri...

-Marine plastic pollution is worse than expected, and we are starting to realize its full extent and severity. Solving the plastic pollution problem is not easy, as it requires the action and commitment of all sectors of our society. With a coastline extending over 4,000 km (from 18°S to 56°S), Chile is a maritime country, and since plastics are po...

Microbial symbionts of marine sponges play important roles for the hosts and also for their ecosystems. The unique tolerance of marine sponges to a wide diversity of microbial symbionts allows them to acquire a wide variety of “evolutionary solutions” to environmental challenges. Ice scour is one of the main forces structuring Antarctic benthic com...

Thermophilic microorganisms have always been an important part of the ecosystem, particularly in a hot environment, as they play a key role in nutrient recycling at high temperatures where most microorganisms cannot cope. While most of the thermophiles are archaea, thermophiles can also be found among some species of bacteria. These bacteria are ve...

In order to develop powerful predictions on the impact of climate change on marine organisms, it is critical to understand how abiotic drivers such as temperature can directly and indirectly affect marine organisms. Here, we evaluated and compared the physiological vulnerability of the leading-edge populations of two species of sea urchins Loxechin...

Although the cellular and molecular responses to exposure to relatively high temperatures (acute thermal stress or heat shock) have been studied previously, only sparse empirical evidence of how it affects cold-water species is available. As climate change becomes more pronounced in areas such as the Western Antarctic Peninsula, both long-term and...

Marine sponges host dense, diverse, and species-specific microbial communities around the globe; however, most of the current knowledge is restricted to species from tropical and temperate waters. Only recently, some studies have assessed the microbiome of a few Antarctic sponges; however, contrary to low mid-latitude sponges, the knowledge about t...

Introducción: El camarón hada Branchinecta gaini habita en las lagunas de la Península Antártica. Estas lagunas se caracterizan por presentar un amplio rango de temperaturas, las cuales pueden llegar a 10ºC en verano y-6ºC en invierno 1. Este crustáceo demuestra una gran flexibilidad fisiológica para sobrevivir en estos ambientes 2 , aunque hasta e...

Los contaminantes emergentes han alcanzado lugares prístinos como es Antártica. Los organismos habitantes de este lugar son centinelas de los cambios ambientales. El depredador tope de las tramas tróficas en los sistemas límnicos Branchinecta gaini depende del medio en el que se desarrolla, por lo que la influencia de contaminantes como NPs TiO 2 e...

Plastic debris has been recognised as a potential stressor for Antarctic marine organisms. In this study, the effects of surface charged polystyrene nanoparticles (PS NPs) on the immune cells (coelomocytes) of the Antarctic sea urchin Sterechinus neumayeri were assessed through in vitro short-term cultures. The behaviour of anionic carboxylated (PS...

Antarctic organisms have evolved according to powerful geological and climate factors which, over millions of years, have shaped the marine fauna. The majority are stenotherms, which is to say that they can live only within a narrow temperature range, generally between-1.8 and 2 degrees C, which means that all of their cellular and molecular proces...

King George Island (KGI) and Deception Island (DCI) are members of the South Shetland Islands in Antarctica, each with their own landscape and local environmental factors. Both sites are suitable for long-term monitoring of bacterial diversity shift due to warming, as temperature rises relatively faster than East Antarctica. This study was conducte...

Psychrophilic and psychrotrophic bacteria play important roles in nutrient cycling in cold environments. These bacteria are suitable as model organisms for studying cold-adaptation, and sources of cold-active enzymes and metabolites for industrial applications. Here, we report the genome sequences of two Cryobacterium sp. strains SO1 and SO2. Genes...

Antarctic marine organisms have developed in an environment of low temperatures and high levels of stability. Consequently, these species have lost the ability to adapt to sudden changes in temperature. Rising ocean temperatures could make the Antarctic sea urchin Sterechinus neumayeri vulnerable to pathogens, triggering responses that increase oxi...

Although the cellular and molecular responses to exposure to relatively high temperatures (acute thermal stress or heat shock) have been studied previously, only sparse empirical evidence of how it affects cold-water species is available. As climate change becomes more pronounced in areas such as the Western Antarctic Peninsula, it has become cruci...

Se asume que los Polos son lugares prístinos donde el impacto humano es muy menor comparado con otras zonas del planeta. Sin embargo, estudios recientes han mostrado la presencia de plásticos en amplios sectores de ambas zonas polares. Es así, como los Océanos Polares contienen cantidades crecientes de microplásticos que podrían impactar los ecosis...

The Antarctic fairy shrimps crustacean Branchinecta gaini (Branchiopoda, Anostraca) inhabits freshwater lakes and pools in Antarctica, one of the most hostile environments on earth. In Maritime Antarctica occurs in several fresh water lakes in Fildes Peninsula (King George Island, South Shetland Islands). This crustacean showed a great physiologica...

Sponges belonging to genus Mycale are common and widely distributed across the oceans and represent a significant component of benthic communities in term of their biomass, which in many species is largely composed by bacteria. However, the microbial communities associated with Mycale species inhabiting different geographical areas have not been pr...

Antarctic organisms have evolved according to powerful geological and climate factors which, over millions of years, have shaped the marine fauna. The majority are stenotherms, which is to say that they can live only within a narrow temperature range, generally between -1.8 and 2 degrees C, which means that all of their cellular and molecular proce...

Microbial abundance List of the 25 most abundant OTUs in samples of Mycale (Oxymycale) acerata and Mycale (Aegogropila) magellanica as shown in Fig. 4.

OTUs in Mycale spp Relative abundance and taxonomy of 97% OTUs in samples of Mycale (Oxymycale) acerata and Mycale (Aegogropila) magellanica.

Microbial richness Observed (A) and estimated (B) microbial richness in samples of Mycale (Aegogropila) magellanica (blue) and Mycale (Oxymycale) acerata (red) from Rio Seco, Magallanes and from Fildes (King George Island) and South Bay (Doumer Island), WAP.

Dominant sponge communities have been described from several areas around the Antarctic. However, little remains known about sponges in shallow waters, where they have been normally reported rarely. In recent years, diverse communities have been described in several sites around King George Island and the western Antarctic Peninsula, suggesting the...

Background: Heat stress proteins are implicated in stabilizing and refolding denatured proteins in vertebrates and invertebrates. Members of the Hsp70 gene family comprise the cognate heat shock protein (Hsc70) and inducible heat shock protein (Hsp70). However, the cDNA sequence and the expression of Hsp70 in the Antarctic sea urchin are unknown. M...

Soil microbes play important roles in global carbon and nutrient cycling. Soil microfungi are generally amongst the most important contributors. They produce various extracellular hydrolase enzymes that break down the complex organic molecules in the soil into simpler form. In this study, we investigated patterns of amylase and cellulase (which are...

The Western Antarctic Peninsula (WAP) has undergone significant changes in air and seawater temperatures during the last 50 years. Although highly stenotherm Antarctic organisms are expected to be severely affected by the increase of seawater temperature, high-resolution datasets of seawater temperature within coastal areas of the WAP (where divers...

Mean daily temperature values recorded at PY1

Raw temperature values recorded at PY2

Summer seawater temperatures Seawater temperature recorded at 10 m in summer (January-February) 2016 and 2017 at Doumer Island, WAP. Dots represent daily means.

Method of finite differences First derivative of the fitted temperature trend for PY1. Periods of higher rates of change are indicated by coloured sections of the trend.

Mean daily temperature values recorded at PY4

R code for Generalized Additive model and method of finite differences Within-year Generalized Additive model (GAM) for PY1, PY2 and PY4. PY1_Method of finite differences (Curtis & Simpson, 2014; Monteith et al., 2014).

Raw temperature values recorded at PY1

Mean daily temperature values recorded at PY2

Raw temperature values recorded at PY4

• The projected changes in water T° and OA constitute major threats to ecosystem functioning, services and integrity, as they can affect key functional species, thus affecting their associated ecosystem processes (Berg et al. 2010). • Sponges are important members of Antarctic benthic communities (Cárdenas et al. 2016), potentially playing a centra...

The Antarctic sea urchin Sterechinus neumayeri has evolved under a cold and thermally stable environment for million years, as most of the Antarctic coastal benthic organisms. Antarctic sea urchins have a low metabolic rate; however the activation of the immune response is possible at low temperatures. Those responsible for initiating the immune re...

As part of the study of the resilience of Antarctic crustaceans to global warming, the shrimp Chorismus antarcticus was subjected to an analysis of global approach using the Next Generation Sequencing Illumina Hi-Seq platform. With this data a detailed study into the principal neuropeptides and neurohormones of this species have been undertaken. To...

The Western Antarctic Peninsula is experiencing some of the most rapid climatic warming on the planet. The projected changes in water T° and OA constitute major threats to ecosystem functioning, services and integrity, as they can affect key functional species, thus affecting their associated ecosystem processes (Berg et al. 2010). Sponges are impo...

The Patagonian toothfish Dissostichus eleginoides is one of the most important fisheries from the Southern Ocean. The biology of this species is relatively well studied and some nutritionals issues have also been reported; however there is no information about the composition of the bacterial community of the gastrointestinal tract, which is essent...