Publicaciones

Oenological and Quality Characteristic on Young White Wines (Sauvignon Blanc): Effects of High Hydrostatic Pressure Processing

Briones-Labarca, V., Perez-Wom, M., Habib, G., Giovagnoli-Vicuña, C., Cañas-Sarazua, R., Tabilo-Munizaga, G., & Salazar, F. N.

High hydrostatic pressure (HHP) has shown to have an effect of enhancing some properties without detrimental effects on important quality characteristics, such as colour, pH, and turbidity. This suggests that this technique can be used as an alternative to the existing methods used in wine industry processing. The aim of this study was to investigate the effects of HHP on aroma compounds and also sensory and quality properties of young white wine. HHP treatment did not influence physicochemical parameters, total phenols, and flavonoid contents of white wine; however, the results from analysis of wine indicate that there was a great variation in the concentration of free and total sulphur dioxide (SO2) values and antioxidant capacity of white wine after HHP application. The sensory attributes, such as taste, odour, and overall quality, were not affected by HHP processing at 300 MPa. The chromatic characteristics changed slightly after applying HHP, but these changes could not be visually perceived because they were less than 5%. The use of this technique has the potential to decrease the amount of SO2 added to raw grapes thus maintaining the same properties found in untreated wine. This study provided valuable insights into the biochemical and sensory composition of commercial white wine and how this might change during HHP processing.

Año: 2017

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Daily and seasonal changes of photobiological responses in floating bull kelp Durvillaea antarctica (Chamisso) Hariot (Fucales: Phaeophyceae)

Tala, F., Penna-Díaz, M. A., Luna-Jorquera, G., Rothäusler, E., & Thiel, M.

Floating seaweeds are important dispersal vehicles, especially for organisms with limited movement capacities and for the seaweeds themselves. The persistence of floating seaweeds is determined by the balance between their acclimation potential and the environmental pressures at the sea surface. Solar radiation is the most important inducer of physiological stress, varying in intensity throughout the day and the year. Therefore photoinhibition and subsequent recovery can change depending on the daily radiation dose and season. The bull kelp Durvillaea antarctica is one of the most common floating seaweeds in the southern oceans, including New Zealand, Chile, and most subantarctic islands. Herein, daily cycles of maximum quantum yield (Fv/Fm), photoinhibition and recovery levels were examined in microcosm experiments with floating D. antarctica throughout the year, focusing on the blade side exposed to solar radiation (sunny vs shadow side). Also, the effect of simulated wave action (blade turnover) and ultraviolet radiation (UVR) on photoinhibition and recovery of Fv/Fm was evaluated. Significant differences in maximum quantum yield were observed between blade sides, with lowest values on the sun-exposed side, especially during noontime and spring/summer months. Phlorotannins and pigments were measured during seasons with the most intense solar radiation (late spring, early summer), when Fv/Fm values were lowest. Phlorotannin, but not pigment concentrations, differed between sunny (lower concentration) and shadow blade sides (higher concentration) and throughout the daily cycle. Both blade sides had similar photoinhibition and recovery levels when blades were constantly turned over. Absence of UVR favoured the recovery capacity of Fv/Fm in both blade sides, suggesting that the photorecovery potential of floating kelps depends on the environmental conditions that kelp rafts face at the sea surface (e.g. cloudy vs sunny days, intense seawater movement and splashing vs calm sea conditions). The results confirm that photobiological stress is more severe during summer and on continuously sun-exposed blade sides, thereby damaging the blades and suppressing the floating time of D. antarctica.

Año: 2017

Palabras claves: Durvillaea antarctica, Floating kelps, in vivo fluorescence, Photoinhibition, Recovery, Solar radiation

Temperate rocky subtidal reef community reveals human impacts across the entire food web

Perez-Matus, A., Ospina-Alvarez, A., Camus, P. A., Carrasco, S. A., Fernandez, M., Gelcich, S., Godoy, N., Ojeda, F.P., Pardo, L.M., Rozbaczylo, N., Subida, M.D., Thiel, M., Wieters, E.A., & Navarrete, S.

Food webs as representations of who eats whom are at the core of community ecology. Incorporation of tools from network theory enables assessment of how complex systems respond to natural and human-induced stressors, revealing how harvesting may degrade the properties and resilience of food webs. We present a comprehensive, coastal marine food web that includes 147 taxa co-occurring on shallow subtidal reefs along the highly productive and exploited Humboldt Current System of central Chile. This food web has connectance of 0.06, link density of 1204 and mean chain length of 4.3. The fractions of intermediate (76%), omnivorous (49%) and cannibalistic (8%) nodes are slightly lower than those observed in other marine food webs. Of the 147 nodes, 34 are harvested. Links to harvested nodes represented 50 to 100% of all trophic links of non-harvested nodes, illustrating the great impact that fishery pressure can have on the food web. The food web was compartmentalized into 5 sub-webs with high representation of harvested taxa. This structure changes if the fishery node is removed. Similarity analyses identified groups of harvested species with non-harvested nodes, suggesting that these tropho-equivalents could be sentinel species for the community-wide impacts of coastal fisheries. We conclude that fishing effects can be transmitted throughout the food web, with no compartments completely unaffected by harvesting. It is urgent to establish monitoring programs for community-wide effects of fisheries and assess whether resilience of these highly productive subtidal food webs has already been compromised, thereby identifying essential nodes that require stronger fisheries regulation.

Año: 2017

Palabras claves: Network structure, Marine ecosystems, Fishery, Resilience, Chile

Who cares about dirty beaches? Evaluating environmental awareness and action on coastal litter in Chile

Kiessling, T., Salas, S., Mutafoglu, K., & Thiel, M

Coastal litter is a source of environmental, economic and health-related problems in many parts of the world, but local responses are not necessarily related to the severity of the impacts. In particular, it is unclear how environmental perception of community members and government bodies relate to active engagement on coastal pollution. The present study analyses the coastal litter situation and evaluates the willingness of citizens to engage at four sites (three regions of mainland Chile, and Easter Island; henceforth Rapa Nui) that feature differences in culture, economy sectors and landscape characteristics. Data on coastal litter were obtained from citizen science campaigns and assessments of large litter accumulations on beaches and rocky shores. The willingness to engage was evaluated qualitatively, considering municipal planning documents and the perception of residents on coastal litter and general waste management. We found very large quantities of litter in northern Chile, posing a hazard to marine wildlife and human health, and moderate quantities in the other regions. The region with the most severe case of coastal pollution does not feature the highest engagement, possibly a result of underlying factors such as an unsustainable economy and few possibilities for the population to connect with the natural environment. On mainland Chile, municipal engagement is low to moderate while on Rapa Nui there exist integrated waste-management strategies that address coastal pollution. Inhabitants of Rapa Nui seem to have a better conduct in the coastal environment (picking up litter, littering less), and show more engagement in waste-reduction strategies (recycling, volunteering for beach clean-ups). We suggest that the unique cultural history of the island, a landscape that allows meaningful interaction with nature and an economy based on sustainable tourism and high international visibility facilitates engagement on environmental issues. We advise managers to consider respective underlying variables, to create environments that allow contact with nature (e.g. public access to parks), and to encourage bottom-up initiatives, preferably by local actors (e.g. by promoting already engaged individuals or organisations).

Año: 2017

Palabras claves: Marine litter, Willingness to engage, Socio-economic factors, Pro-environmental behaviour, Waste management

Comparative population genetics of two dominant plant species of high Andean wetlands reveals complex evolutionary histories and conservation perspectives in Chile’s Norte Chico

Troncoso, A. J., Bertin, A., Osorio, R., Arancio, G., & Gouin, N.

High Andean wetlands are naturally fragmented ecosystems that are impacted by anthropogenic activities. Although they constitute important reservoirs of biodiversity and ecosystem service providers, many aspects of their ecology are still unknown. In this study, we investigated the population genetic structure of two dominant and highly interactive plant species of high altitude wetlands, Patosia clandestina (Juncaceae) and Carex gayana (Cyperaceae), in 21 high Andean wetlands of Chile’s Norte Chico. Using rbcL gene sequences and AFLP markers, we found that both species displayed low levels of within-wetland genetic diversity, high inter-population genetic differentiation, and spatially-dependent genetic variation arising from isolation-by-distance. The distance at which populations become genetically independent was of the same order of magnitude in both species (125–175 km). Despite these similarities, idiosyncratic spatial patterns were detected. C. gayana in the three most northeastern wetlands demonstrated marked differences relative to the rest of the populations, with the latter group following a latitudinal stepping-stone pattern. In P. clandestina, a genetic barrier was found to divide the northern and southern populations into two balanced groups, and spatial genetic variation was consistent with a hierarchical island model. The data indicate that each of the two species likely responded to different geological and ecological events, resulting in the definition of unique evolutionarily significant units in both. These results suggest that the implementation of global conservation programs at regional scales would likely result in the loss of important components of biodiversity in these ecosystems, and underscore the need for caution in designing effective conservation strategies.

Año: 2017

Palabras claves: AFLP, Carex gayana, Genetic diversity, Patosia clandestina, Population differentiation, Evolutionarily significant units

On the indiscriminate use of imported emission factors in environmental impact assessment: A case study in Chile

Bernal, M. F., Oyarzún, J., & Oyarzún, R.

Environmental Impact Assessment (EIA) aims to determine if the environmental effect of an activity or project complies with standards and regulations. A primary component of the environment to evaluate is air and the effect that various activities can have on its quality. To this end, emission factors (EFs), which are empirical coefficients or mathematical relationships, are normally used. The present research critically analyzes the implications and consequences of using imported EFs in environmental impact studies (EISs), taking as case of study the situation in Chile. Among the main results, the widespread use of EFs in EISs in the country and the lack of assessments of their actual applicability stand out. In addition, the official guidelines related to emissions estimation that are used for EIA in the country mostly include EFs derived elsewhere, without considering the recommendations or restrictions that the original sources indicate for their use. Finally, the broad use of default values defined for the Metropolitan Region in Central Chile, is highly questionable for a country that extends north-south along more than 35° of latitude, with wide variability in climate, traffic conditions, population, soil types, etc. Finally, it is very likely that situations similar to those observed in the present work occurs in other countries with young environmental impact assessment systems, and therefore, that the results herein presented should be of general interest and relevance.

Año: 2017

Palabras claves: Empirical models, Law 20417, Air quality, Environmental management

A simple approach for the analysis of the structural-geologic control of groundwater in an arid rural, mid-mountain, granitic and volcanic-sedimentary terrain: The case of the Coquimbo Region, North-Central Chile

Oyarzún, R., Oyarzún, J., Fairley, J. P., Núñez, J., Gómez, N., Arumí, J. L., & Maturana, H.

A practical approach for the assessment of surface water and groundwater resources in rain-fed mid-mountain domains of arid to semi-arid zones is much needed, especially in rural areas for which groundwater is the only reliable and permanent water supply source. This is the case in the Coquimbo region (29°15′- 32°10′ S latitude) of north-central Chile, where groundwater is needed for human consumption but also for agricultural and mining activities at a small to medium scale. This paper examines the usefulness of community knowledge, as encoded in the historical record, for identifying water resources. The existing record of wells and springs in the Coquimbo region is used as a guide to the identification and characterization of structural patterns that may influence the distribution of water resources. The proposed approach combines simple graphical, statistical and geostatistical methods to identify patterns, likely related to local and regional structural controls that influence the distribution of groundwater resources. In the Coquimbo area, these influences tend to align in NW and NE orientations that approximately coincide with regional geological trends. The methodology presented has the potential to form a first step in the search for additional water resources in the Coquimbo region, and may be useful for targeting detailed field studies on the basis of community and historical knowledge in many arid and semi-arid rural areas.

Año: 2017

Palabras claves: Wells, Springs, Rain-fed area, Drylands, Geohydrology

Diversity of deep-sea fishes of the Easter Island Ecoregion

Easton, E. E., Sellanes, J., Gaymer, C. F., Morales, N., Gorny, M., & Berkenpas, E.

The Easter Island Ecoregion is in the center of the South Pacific gyre and experiences ultra-oligotrophic conditions that could make it highly susceptible to global change and anthropogenic activities, so it is imperative that these regions are characterized and studied so that conservation and sustainable management strategies can be developed. From the few studies from the region, we know that the coastal areas are relatively depauperate and have relatively high rates of endemism. Here, we present a brief report from the first video observations from this region of the deep-dwelling fishes from ROV exploration of benthic communities from 157 to 281 m and baited drop-camera videos from 150 to 1850 m. We observed a total of 55 fish species from the ROV and Drop-Cam surveys; nine could not be assigned family level or lower, 26 were observed in the ROV surveys, 29 were observed in the Drop-Cam surveys, nine were observed with both survey methods, at least six species are potentially new to science, and nine species were observed at deeper depths than previously reported. These new reports may be indicative of the unique oceanographic conditions in the area and the relative isolation of the communities that have provided opportunity for the evolution of new species and favorable conditions for range expansion. In contrast, these new reports may be indicative of the severe undersampling in the south Pacific at mesopelagic depths. The prevalence of potentially new species suggests that the region likely harbors a wealth of undiscovered biodiversity.

Año: 2017

Palabras claves: MesophoticSqualus, Chromis, Tosanoides, Hydrolagus, Benthic ecology

Artificial defences in coastal marine ecosystems in Chile: Opportunities for spatial planning to mitigate habitat loss and alteration of the marine community structure

Aguilera, M. A.

Many coastal habitats are actually replaced with hard infrastructures which alter the taxonomic/functional structure of natural ecosystems worldwide. Few information about habitat loss and species composition in South American coasts are available compared with other coasts. Here, I examine the distribution and identity of coastal artificial infrastructures, especially artificial breakwaters, present along the coast of Chile and the proportion of natural habitat loss derived from their construction. Differences in species taxonomic/functional composition in artificial breakwaters and natural habitats present in northern Chile are also examined. I also propose/discuss opportunities for coastal planning based on habitat rehabilitation and ecological engineering in Chile, which could guide future marine infrastructures construction. An important proportion of natural habitat has been replaced by artificial coastal defences along the coast of Chile, accounting for about 200 km of total coastal length. Given their specific uses and functions, artificial granite breakwaters are one of the most important coastal infrastructures present in Chile (62% of the total of artificial breakwaters present). Differences in taxonomic/functional structure between artificial breakwaters and natural adjacent habitats are significant, and appear related to contrasting spatial heterogeneity. Artificial infrastructures like granite breakwaters can facilitate presence of native and non-native species, which live in the marine-terrestrial interphase (crabs, rats). The present study highlights how the recent proliferation of coastal artificial infrastructures is replacing important natural habitats in Chile, and how the taxonomic/functional structure of coastal ecosystems can be negatively impacted. Furthermore, this study showed how artificial infrastructures can have direct consequences for human-health security and specific guidelines can be conducted to buffer impacts on ecosystem structure to match social livelihood and wellness.

Año: 2017

Palabras claves: Habitat loss, Coastal ecosystem, Functional structure, RehabilitationChile