Examinando por Autor "Duarte, Cristián"

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    Ítem
    Acidification and high-temperature impacts on energetics and shell production of the edible clam Ameghinomya antiqua
    (Frontiers Media S.A., 2022-09) Martel, Sebastián I.; Fernández, Carolina; Lagos, Nelson A.; Labra, Fabio A.; Duarte, Cristián; Vivanco, Juan F.; García Herrera, Claudio; Lardies, Marco A.
    Warming and ocean acidification are currently critical global change drivers for marine ecosystems due to their complex and irreversible effects on the ecology and evolution of marine communities. Changes in the chemistry and the temperature of the ocean impact the biological performance of marine resources by affecting their energy budget and thus imposing energetic restrictions and trade-offs on their survival, growth, and reproduction. In this study, we evaluated the interplaying effects of increased pCO2 levels and temperature on the economically relevant clam Ameghinomya antiqua, an infaunal bivalve inhabiting a wide distributional range along the coast of Chile. Juvenile clams collected from southern Chile were exposed to a 90-day experimental set-up emulating the current and a future scenario projeced to the end of the current century for both high pCO2/low-pH and temperature (10 and 15°C) projected for the Chilean coast. Clams showed physiological plasticity to different projected environmental scenarios without mortality. In addition, our results showed that the specimens under low-pH conditions were not able to meet the energetic requirements when increased temperature imposed high maintenance costs, consequently showing metabolic depression. Indeed, although the calcification rate was negative in the high-pCO2 scenario, it was the temperature that determined the amount of shell loss. These results indicate that the studied clam can face environmental changes for short-term periods modifying energetic allocation on maintenance and growth processes, but with possible long-term population costs, endangering the sustainability of an important benthic artisanal fisheries resource. Copyright © 2022 Martel, Fernández, Lagos, Labra, Duarte, Vivanco, García-Herrera and Lardies.
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    Determinación y evaluación de los componentes presentes en las pinturas anti-incrustantes utilizadas en la acuicultura y sus posibles efectos en sedimentos marinos en el sur de Chile
    (Pontificia Universidad Católica de Valparaíso. Facultad de Recursos Naturales. Escuela de Ciencias del Mar, 2015) Vera, Rodrigo; Duarte, Cristián; Pinilla, Elías; Murillo, Vladimir; Oyarzún, Marina; Aroca, Gésica
    Se realizaron muestreos de sedimento en tres áreas relacionadas con el uso de pinturas anti-incrustantes en la salmonicultura en el sur de Chile, con el fin de detectar alteraciones en la abundancia o diversidad de la macrofauna bentónica debidas a la acumulación de metales como Cu y Zn en los sedimentos. Los resultados muestran que existe acumulación especialmente de Cu en los sedimentos aledaños a las balsas jaulas de cultivo, pero no se apreciaron variaciones significativas en la composición ni en la abundancia de la macrofauna bentónica asociada a estos centros de cultivo, aun cuando las concentraciones de Cu superaron los 800 μg g-1 en el sedimento.
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    Geographical Variation in Phenotypic Plasticity of Intertidal Sister Limpet’s Species Under Ocean Acidification Scenarios
    (Frontiers Media S.A., 2021-05) Lardies, Marco Antonio; Caballero, Paz; Duarte, Cristián; Poupin, María Josefina
    Ocean Acidification (OA) can have pervasive effects in calcifying marine organisms, and a better understanding of how different populations respond at the physiological and evolutionary level could help to model the impacts of global change in marine ecosystems. Due to its natural geography and oceanographic processes, the Chilean coast provides a natural laboratory where benthic organisms are frequently exposed to diverse projected OA scenarios. The goal of this study was to assess whether a population of mollusks thriving in a more variable environment (Talcaruca) would present higher phenotypic plasticity in physiological and morphological traits in response to different pCO2 when compared to a population of the same species from a more stable environment (Los Molles). To achieve this, two benthic limpets (Scurria zebrina and Scurria viridula) inhabiting these two contrasting localities were exposed to ocean acidification experimental conditions representing the current pCO2 in the Chilean coast (500 μatm) and the levels predicted for the year 2100 in upwelling zones (1500 (μatm). Our results show that the responses to OA are species-specific, even in this related species. Interestingly, S. viridula showed better performance under OA than S. zebrina (i.e., similar sizes and carbonate content in individuals from both populations; lower effects of acidification on the growth rate combined with a reduction of metabolism at higher pCO2). Remarkably, these characteristics could explain this species’ success in overstepping the biogeographical break in the area of Talcaruca, which S. zebrina cannot achieve. Besides, the results show that the habitat factor has a strong influence on some traits. For instance, individuals from Talcaruca presented a higher growth rate plasticity index and lower shell dissolution rates in acidified conditions than those from Los Molles. These results show that limpets from the variable environment tend to display higher plasticity, buffering the physiological effects of OA compared with limpets from the more stable environment. Taken together, these findings highlight the key role of geographic variation in phenotypic plasticity to determine the vulnerability of calcifying organisms to future scenarios of OA. © Copyright © 2021 Lardies, Caballero, Duarte and Poupin.