CEAZA
Changes of heritability and genetic correlations in production traits over time in red abalone ( Haliotis rufescens ) under culture.
Brokordt, K., Winkler, F., Farías, W., González, R., Castaño, F., Fullsack, P., & Herbinger, C.
Red abalone Haliotis rufescens is one of the most valuable mollusks in the international market, but it has a low growth rate. A breeding program is being developed to increase its growth rate in Chile. We estimated the changes in direct heritability (h2), maternal/common environments heritability (m2) and genetic correlations (rG) of growth traits (shell length and width, total mass, flesh mass and foot protein as an indicator of meat quality) measured during 2 years (every 4 months) from the juvenile stage (27 months) to the adult harvesting age (51 months), in 60 full-sib red abalone families. Heritabilities for growth traits measured in juveniles and young adults (27–35 months of age), were low (0.07–0.17) and not significant. Initial low h2 were associated with significant amounts of maternal/common environmental effects (m2 = 0.4). In young adults and abalone near the harvest age (39–51 months of age) h2 were much higher (0.32–0.75). These results emphasize the importance of multiple estimations of h2 over time. Among meat quality traits, only the h2 for the flesh mass for adults at harvesting age was significant (0.15). We observed strong positive rG (>0.9) between shell sizes (easy to measure) and total and flesh masses (trait more related to market value than shell sizes but harder to measure) for adults at harvesting age. Thus, if the 5% largest 51 month old abalone were selected from the population as broodstock we expect a positively correlated response on flesh mass of 23.4%.
Año: 2015
Palabras claves: Abalone aquaculture; heritability; maternal effects; growth; genetic improvement; Haliotis rufescens.
Referencia APA: Brokordt, K., Winkler, F., Farías, W., González, R., Castaño, F., Fullsack, P., & Herbinger, C. (2015). Changes of heritability and genetic correlations in production traits over time in red abalone (Haliotis rufescens) under culture. Aquaculture Research, 46(9), 2248-2259.
Mitochondrial DNA diversity of feral pigs from Karukinka Natural Park, Tierra del Fuego Island, Chile.
Aravena, P., Skewes, O., & Gouin, N.
: Control or eradication of exotic species is one of the greatest challenges facing biodiversity and ecosystem conservation. Domestic pigs (Sus scrofa domestica) were released and became feral in the southern region of Chilean Tierra del Fuego Island in the 1900s.
Currently, they inhabit part of Karukinka Natural Park, an area of global conservation concern. To gain insight into the control of this invasive species, we analyzed genetic variation in the mitochondrial DNA control region to determine the origin and population subdivision of feral pigs in Tierra del Fuego. Sequences from a sample of 42 feral pigs, 10 domestic pigs from local farms, and references from other countries and commercial breeds revealed 2 highly differentiated populations,
1 in the western and the other in the eastern area of the park, each harboring a different haplotype, suggesting no connectivity between populations. Comparison of these haplotypes with reference sequences from other countries and commercial breeds indicated that feral pigs from Chilean Tierra del Fuego are of European origin, very likely from
2 separate introduction events. The haplotype found in the western feral population was also identified in domestic pigs from a farm. This raises concerns regarding the possible connectivity between stocks from local farms and the wild population. Based on these results, we recommend the development of strategies for controlling the population of this invasive species in Karukinka Natural Park.
Año: 2015
Palabras claves: Feral pigs; Invasive species; mtDNA control region;Sus scrofa; Tierra del Fuego Island.
Referencia APA: Aravena, P., Skewes, O., & Gouin, N. (2015). Mitochondrial DNA diversity of feral pigs from Karukinka Natural Park, Tierra del Fuego Island, Chile. Genetics And Molecular Research, 14(2), 4245-4257.
Tefrocronología en curso superior del valle del río Cisne (44°S), Chile Austral.
Stern, C., De Porras, M., & Maldonado, A.
Based on their petrography and chemistry, 18 tephra analyzed from two lake and bog cores and one outcrop in the upper Río Cisnes valley are believed to have been derived from nine different eruptions of the Mentolat volcano, four of the Melimoyu volcano, and one from the Hudson volcano. Some of these tephra correlate chronologically and petrochemically with previously documented large eruptions of these volcanoes, including the Late-Glacial Ho eruption of Hudson (17,340 cal yrs BP), the mid-Holocene MEN1 eruption of Mentolat (7,710 cal yrs BP), and the Late-Holocene MEL2 eruption of Melimoyu (1,680 cal yrs BP). A Melimoyu-derived tephra from the outcrop occurs in glacial-lacustrine sediments and is considered to pre-date the Last Glacial Maximum (>19,670 cal yrs BP). The data suggest that none of the tephra were produced by explosive eruptions of the Maca, Cay and Yanteles volcanoes.
Año: 2015
Palabras claves: Tephra, Tephrochronology, Tephrostratigraphy, Volcanism, Andes, Chile.
Referencia APA: Stern, C., De Porras, M., & Maldonado, A. (2015). Tefrocronología en curso superior del valle del río Cisne (44°S), Chile Austral. Andean Geology, 42(2).
Detecting Subtle Seasonal Transitions of Upwelling in North-Central Chile.
Rahn, D., Rosenblüth*, B., & Rutllant, J.
Biological productivity in the ocean along the Chilean coast is tied to upwelling that is primarily forced by equatorward wind stress and wind stress curl on the ocean surface. Southerly alongshore flow is driven by the southeast Pacific (SEP) anticyclone, and its intensity and position vary on a range of time scales. Variability of the SEP anticyclone has been linked to large-scale circulations such as El Niño–Southern Oscillation and the Madden–Julian oscillation. The actual timing, duration, and nature of the seasonal meridional drift of the SEP anticyclone are associated with the onset, demise, and strength of the local upwelling season. Seasonal variation is especially marked at the Punta Lavapié (37°S) upwelling focus, where there is a clear upwelling season associated with a change of the cumulative upwelling index (CUI) slope between positive and negative. The Punta Lengua de Vaca (30°S) focus typically exhibits upwelling year-round and has less distinct transitions, making it more difficult to identify an enhanced upwelling season. A two-phase linear regression model, which is typically used to detect subtle climate changes, is applied here to detect seasonal changes in CUI at Punta Lengua de Vaca. This method objectively finds distinct transitions for most years. The spring-to-summer transition is more readily detected and the slackening of the upwelling-favorable winds, warmer waters, and longer wind strengthening–relaxation cycles change the coastal upwelling ecosystem. While the spring-to-summer transition at Punta Lengua de Vaca could be influenced by large-scale circulations, the actual dates of transition are highly variable and do not show a clear relationship.
Año: 2015
Palabras claves: Circulation/ Dynamics; Upwelling/downwelling; Atm/Ocean Structure/ Phenomena; Madden-Julian oscillation; Physical Meteorology and Climatology; Climate variability; Coastal meteorology; ENSO.
Referencia APA: Rahn, D., Rosenblüth*, B., & Rutllant, J. (2015). Detecting Subtle Seasonal Transitions of Upwelling in North-Central Chile. J. Phys. Oceanogr., 45(3), 854-867.
Potential Response to Selection of HSP70 as a Component of Innate Immunity in the Abalone Haliotis rufescens.
Brokordt, K., González, R., Farías, W., & Winkler, F.
Assessing components of the immune system may reflect disease resistance. In some invertebrates, heat shock proteins (HSPs) are immune effectors and have been described as potent activators of the innate immune response. Several diseases have become a threat to abalone farming worldwide; therefore, increasing disease resistance is considered to be a long-term goal for breeding programs. A trait will respond to selection only if it is determined partially by additive genetic variation. The aim of this study was to estimate the heritability (h2) and the additive genetic coefficient of variation (CVA) of HSP70 as a component of innate immunity of the abalone Haliotis rufescens, in order to assess its potential response to selection. These genetic components were estimated for the variations in the intracellular (in haemocytes) and extracellular (serum) protein levels of HSP70 in response to an immunostimulant agent in 60 full-sib families of H. rufescens. Levels of HSP70 were measured twice in the same individuals, first when they were young and again when they were pre-harvest adults, to estimate the repeatability (R), the h2 and the potential response to selection of these traits at these life stages. High HSP70 levels were observed in abalones subjected to immunostimulation in both the intracellular and extracellular haemolymph fractions. This is the first time that changes in serum levels of HSP70 have been reported in response to an immune challenge in molluscs. HSP70 levels in both fractions and at both ages showed low h2 and R, with values that were not significantly different from zero. However, HSP70 induced levels had a CVA of 13.3–16.2% in young adults and of 2.7–8.1% in pre-harvest adults. Thus, despite its low h2, HSP70 synthesis in response to an immune challenge in red abalone has the potential to evolve through selection because of its large phenotypic variation and the presence of additive genetic variance, especially in young animals.
Año: 2015
Palabras claves: Heat shock response, Immune response, Genetic polymorphism, Phenotypes, Young adults, Immune system proteins, Invertebrates, Crop genetics.
Referencia APA: Brokordt, K., González, R., Farías, W., & Winkler, F. (2015). Potential Response to Selection of HSP70 as a Component of Innate Immunity in the Abalone Haliotis rufescens. PLOS ONE, 10(11), e0141959.
Aeolian particles in marine cores as a tool for quantitative high-resolution reconstruction of upwelling favorable winds along coastal Atacama Desert, Northern Chile.
Flores-Aqueveque, V., Alfaro, S., Vargas, G., Rutllant, J., & Caquineau, S.
Upwelling areas play a major role in ocean biogeochemical cycles and ultimately in global climate, especially in higly productive regions as the South Eastern Pacific. This work is based on the analysis of the aeolian lithic particles accumulated in laminated sediments off Mejillones (23°S) in the eastern boundary Humboldt Current System. It proposes a high-resolution quantitative reconstruction of the upwelling-favorable southerly wind strength in the past ∼250 years, comparing its variability with changes in organic carbon export/preserved changes to the sea bottom. The increase of the intensity and variability in fluxes of particles larger than 35 μm and 100 μm since the second half of the 19th century and during the 20th century confirms a general strengthening of southerly winds in the region. Spectral analysis on the complete time-series of yearly depositional fluxes indicates that sedimentary variability can be explained by a combination of interannual (ENSO) to decadal (PDO) oscillations similar to the ones yielded by the analysis of the Interdecadal Pacific Oscillation index. However, when applied separately to the lithic fluxes of the first and last centuries of the time-series, the method shows that relative to the one of the interannual mode of variability, the influence of the decadal mode has increased in the recent period.
Based on the presence/absence of particles with sizes larger than 35/100 μm, each year of the time series is classified as a ‘Low wind’ (<6 m/s), ‘Intermediate wind’ (6–8 m/s), or ‘Strong wind’ (10 to >12 m/s) year. From the AD 1754–1820 period to the AD 1878–1998 one, the proportion of Low and Intermediate wind years decreased from 12% and 74% to 3% and 68%, respectively, whereas the proportion of strong wind years increased from 14% to 29%. For these periods the mean organic carbon also increased 22%, stating the strong relation between export/preservation productivity rate and southerly wind intensity.
In the recent period (from AD 1950 on) for which the Oceanic Niño Index is available, the strong wind years (AD 1982, 1983, 1994, and 1997) correspond to large values of this index, suggesting that constructive interferences that result from the interplay between interannual and decadal oscillations modes might explain in part the reinforcement of the winds along the North Chilean coast.
Año: 2015
Palabras claves:
Referencia APA: Flores-Aqueveque, V., Alfaro, S., Vargas, G., Rutllant, J., & Caquineau, S. (2015). Aeolian particles in marine cores as a tool for quantitative high-resolution reconstruction of upwelling favorable winds along coastal Atacama Desert, Northern Chile. Progress In Oceanography, 134, 244-255.
Pollen morphology of Cactaceae in Northern Chile.
Miesen, F., De Porras, M., & Maldonado, A.
Chile is habitat to over 140 species of cactus of which 45% are endemic and most of them grow in the arid northernmost part of the country between 18°-32°S. As the Cactaceae family plants are quite well adapted to arid environments, their fossil pollen may serve as a tool to reconstruct past environmental dynamics as well as to trace some issues regarding the family evolution or even some autoecological aspects. Aiming to create a reference atlas to be applied to some of these purposes, the pollen morphology of the following 14 different species of the Cactaceae family from Northern Chile was studied under optical microscopy: Cumulopuntia sphaerica, Maihueniopsis camachoi, Tunilla soehrensii, Echinopsis atacamensis, Echinopsis coquimbana, Haageocereus chilensis, Oreocereus hempelianus, Oreocereus leucotrichus, Copiapoa coquimbana, Eriosyce aurata, Eriosyce subgibbosa, Eulychnia breviflora, Browningia candelaris and Corryocactus brevistylus. Pollen grains of species of the subfamily Opuntioideae are spheroidal, apolar and periporate whereas grains of the subfamily Cactoideae are subspheroidal, bipolar and tricolpate and can be taxonomically differentiated between tribes. The results show that it is possible to identify pollen from the Cactaceae family at the genus level but pollen taxonomic resolution may be complicated to identify up to a specific level. A wider reference collection considering more characters than those included in the present study could improve this aspect in the near future.
Año: 2015
Palabras claves: Pollen morphology, Cactaceae, biogeography, palaeoecology, Chile.
Referencia APA: Miesen, F., De Porras, M., & Maldonado, A. (2015). Pollen morphology of Cactaceae in Northern Chile. Gayana Bot., 72(2), 258-271.
Definition of sanitary boundaries to prevent ISAv spread between salmon farms in southern Chile based on numerical simulations of currents.
Olivares, G., Sepúlveda, H., & Yannicelli, B.
The infectious Salmon Anemia virus (ISAv) is a pathogen that mainly affects the Atlantic Salmon (Salmo salar). It was detected in Norway in 1984 and in June 2007 appeared in Chile, producing a drop of more than 30% in the country's production level. It is expected that with certain regularity, outbreaks will continue to appear in Chile without the need of reintroducing the virus from foreign countries. We present a numerical study of the influence of winds and tides in the dispersion of lagrangian particles to simulate the transport of ISAv in the Aysen region, in southern Chile. This study combines the use of numerical models of the ocean and atmosphere, lagrangian tracking and biological aspects of ISAv infections. As in previous results, a wider dispersion of ISAv was observed during spring tides. Temporal changes in wind significantly modified the transport of viral particles from an infected center. Under similar forcing conditions, the areas of risk associated to culture sites separated by a few kilometers could be very different. Our main results remark the importance of the use of a detailed knowledge of hydrographic and atmospheric circulation in the definition of boundaries for sanitary management areas. We suggest that a methodology similar to the one presented in this study should be considered to define sanitary strategies to minimize the occurrence of native outbreaks of ISAv.
Año: 2015
Palabras claves: sanitary boundaries; ISAv; Atlantic Salmon; spread; numerical model; Chile.
Referencia APA: Olivares, G., Sepúlveda, H., & Yannicelli, B. (2015). Definition of sanitary boundaries to prevent ISAv spread between salmon farms in southern Chile based on numerical simulations of currents. Estuarine, Coastal And Shelf Science, 158, 31-39.
Hongos endófitos antárticos como herramienta para la reintroducción de especies nativas en zonas áridas.
Fardella, C., Oses, R., Torres-Díaz, C., & Molina-Montenegro, M.
Ecological restoration is the deliberate action that speeds recovery from a degraded system by direct or indirect human intervention. Xerophytic formations are among the most degraded ecosystems where low water availability makes reintroduction plans unsuccessful and extremely expensive. Roots inoculation with endophytic fungi has been reported as a successful strategy to maintain or improve the ecophysiological performance and survival in different species of shrubs and trees. In harsh environments, endophytes have been shown to provide benefits in terms of survival and growth for their associated vegetation. In this study, we showed that inoculation with endophytes isolated from plants growing in Antarctica improve survival and water use efficiency for irrigation on native species of xerophytic formations: Flourensia thurifera, Senna cumingii and Puya berteroniana. Overall, the presence of endophytes improved survival of all native species. Furthermore, the presence of endophytes improved water use efficiency for irrigation, reaching higher percentages of survival in plants with a reduction in the added water. The application of Antarctic endophytes could be considered a successful strategy for future projects and reintroduction programs in arid and semi-arid zones of Chile.
Año: 2014
Palabras claves: Endophytes, water use efficiency, xerophytic formations, restoration.
Referencia APA: Fardella, C., Oses, R., Torres-Díaz, C., & Molina-Montenegro, M. (2014). Hongos endófitos antárticos como herramienta para la reintroducción de especies nativas en zonas áridas. Bosque (Valdivia), 35(2), 235-239. http://dx.doi.org/10.4067/s0717-92002014000200011
Identifying appropriate spatial scales for marine conservation and management using a larval dispersal model: The case of Concholepas concholepas (loco) in Chile.
Garavelli, L., Kaplan, D., Colas, F., Stotz, W., Yannicelli, B., & Lett, C.
Along the coast of Chile, fisheries targeting the marine gastropod Concholepas concholepas, commonly named “loco”, were highly valuable until the end of the 80s when catches declined significantly. Since the late 90s, a management plan based on territorial-user-rights areas has been implemented, with limited effect on stock recovery. More effective loco conservation and management is impeded by lack of information regarding connectivity via larval dispersal between these individually-managed areas. To develop a regional view of loco connectivity, we integrate loco life history information into a biophysical, individual-based larval dispersal model. This model is used to evaluate scales of loco connectivity and seasonality in connectivity patterns, as well as to partition the coast into largely disconnected subpopulations using a recently developed connectivity-matrix clustering algorithm. We find mean dispersal distances ranging from 170 to 220 km depending on release depth of larvae and planktonic larval duration. Settlement success levels depend quantitatively on the physical and biological processes included in the model, but connectivity patterns remain qualitatively similar. Model estimates of settlement success peak for larval release dates in late austral autumn, consistent with field results and with favorable conditions for larval coastal retention due to weak upwelling during austral autumn. Despite the relatively homogeneous Chilean coastline, distinct subpopulations with minimal connectivity between them are readily identifiable. Barriers to connectivity that are robust to changes in model configuration exist at 23°S and 29°S latitudes. These zones are all associated with important headlands and embayments of the Chilean coast.
Año: 2014
Palabras claves:
Referencia APA: Garavelli, L., Kaplan, D., Colas, F., Stotz, W., Yannicelli, B., & Lett, C. (2014). Identifying appropriate spatial scales for marine conservation and management using a larval dispersal model: The case of Concholepas concholepas (loco) in Chile. Progress In Oceanography, 124, 42-53.
Antarctic macrolichen modifies microclimate and facilitates vascular plants in the maritime Antarctica – a reply to Casanova-Katny et al.
Molina-Montenegro, M., Torres-Díaz, C., & Gianoli, E.
In a current article in the Journal of Vegetation Science, Casanova-Katny et al. addressed a comment about an article by Molina-Montenegro et al., which demonstrated the climate modification induced by the macrolichen Usnea antarctica and its role as facilitator. They provided useful corrections concerning species identification and pointed out several issues that, in their view, weakened our study. They indicated that the role of U. antarctica as a facilitative species in the maritime Antarctica is merely philosophical and has no ecological relevance. In this commentary, we argue why these critiques are unsubstantial, and provide evidence that the macrolichen can modify the microclimate, ameliorating the harsh conditions prevailing in Antarctica, establishing positive interactions and eventually facilitating vascular species. Thus, the macrolichen U. antarctica would act as a ‘nurse species’, playing a key role in structuring the maritime Antarctic plant community.
Año: 2014
Palabras claves: Antarctica; Deschampsia Antarctica; Facilitation; Nurse effect; Positive interactions.
Referencia APA: Molina-Montenegro, M., Torres-Díaz, C., & Gianoli, E. (2014). Antarctic macrolichen modifies microclimate and facilitates vascular plants in the maritime Antarctica - a reply to Casanova-Katny et al. (2014). J Veg Sci, 25(2), 606-608.
Spatial variability in community composition on a granite breakwater versus natural rocky shores: Lack of microhabitats suppresses intertidal biodiversity.
Aguilera, M., Broitman, B., & Thiel, M.
Strong differences have been observed between the assemblages on artificial reefs and on natural hard-bottom habitats worldwide, but little is known about the mechanisms that cause contrasting biodiversity patterns. We examined the influence of spatial attributes in relation to both biogenic and topographic microhabitats, in the distribution and composition of intertidal species on both artificial and natural reefs. We found higher small-scale spatial heterogeneity on the natural reef compared with the study breakwater. Species richness and diversity were associated with a higher availability of crevices, rock pools and mussels in natural habitats. Spatial distribution of certain grazers corresponded well with the spatial structure of microhabitats. In contrast, the lack of microhabitats on the breakwater resulted in the absence of several grazers reflected in lower species richness. Biogenic and topographic microhabitats can have interactive effects providing niche opportunities for multiple species, explaining differences in species diversity between artificial versus natural reefs.
Año: 2014
Palabras claves: Artificial reefs; Biodiversity; Breakwater; Grazers; Spatial heterogeneity; Microhabitats.
Referencia APA: Aguilera, M., Broitman, B., & Thiel, M. (2014). Spatial variability in community composition on a granite breakwater versus natural rocky shores: Lack of microhabitats suppresses intertidal biodiversity. Marine Pollution Bulletin, 87(1-2), 257-268.