Examinando por Autor "Quintanilla-Ahumada, Diego"

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    Artificial Light at Night (ALAN) causes size-dependent effects on intertidal fish decision-making
    (Elsevier, 2023-08) Pulgar, José; Manríquez, Patricio H.; Widdicombe, Stephen; García-Huidobro, Roberto; Quijón, Pedro A.; Carter, Mauricio; Aldana, Marcela; Quintanilla-Ahumada, Diego; Duarte, Cristian
    Artificial Light at Night (ALAN) alters cycles of day and night, potentially modifying species' behavior. We assessed whether exposure to ALAN influences decision-making (directional swimming) in an intertidal rockfish (Girella laevisifrons) from the Southeastern Pacific. Using a Y-maze, we examined if exposure to ALAN or natural day/night conditions for one week affected the number of visits and time spent in three Y-maze compartments: dark and lit arms (“safe” and “risky” conditions, respectively) and a neutral “non-decision” area. The results showed that fish maintained in natural day/night conditions visited and spent more time in the dark arm, regardless of size. Instead, fish exposed to ALAN visited and spent more time in the non-decision area and their response was size-dependent. Hence, prior ALAN exposure seemed to disorient or reduce the ability of rock fish to choose dark conditions, deemed the safest for small fish facing predators or other potential threats. © 2023 Elsevier Ltd.
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    Ítem
    Artificial light pollution influences behavioral and physiological traits in a keystone predator species, Concholepas concholepas
    (Elsevier B.V., 2019-04) H. Manríquez, Patricio; Jara, María Elisa; Diaz, María Isabel; A. Quijón, Pedro; Widdicombe, Stephen; Pulgar, José; Manríquez, Karen; Quintanilla-Ahumada, Diego; Duarte, Cristian
    Artificial Light At Night (ALAN) is an increasing global problem that, despite being widely recognized in terrestrial systems, has been studied much less in marine habitats. In this study we investigated the effect of ALAN on behavioral and physiological traits of Concholepas concholepas, an important keystone species of the south-eastern Pacific coast. We used juveniles collected in intertidal habitats that had not previously been exposed to ALAN. In the laboratory we exposed them to two treatments: darkness and white LED (Lighting Emitting Diodes) to test for the impacts of ALAN on prey-searching behavior, self-righting time and metabolism. In the field, the distribution of juveniles was observed during daylight-hours to determine whether C. concholepas preferred shaded or illuminated microhabitats. Moreover, we compared the abundance of juveniles collected during day- and night-time hours. The laboratory experiments demonstrated that juveniles of C. concholepas seek out and choose their prey more efficiently in darkened areas. White LED illuminated conditions increased righting times and metabolism. Field surveys indicated that, during daylight hours, juveniles were more abundant in shaded micro-habitats than in illuminated ones. However, during darkness hours, individuals were not seen to aggregate in any particular microhabitats. We conclude that the exposure to ALAN might disrupt important behavioral and physiological traits of small juveniles in this species which, as a mechanism to avoid visual predators, are mainly active at night. It follows that ALAN in coastal areas might modify the entire community structure of intertidal habitats by altering the behavior of this keystone species. © 2019
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    Ítem
    Field experimental evidence of sandy beach community changes in response to artificial light at night (ALAN)
    (Elsevier B.V., 2023-05) Duarte, Cristian; Quintanilla-Ahumada, Diego; Anguita, Cristóbal; Silva-Rodriguez, Eduardo A.; Manríquez, Patricio H.; Widdicombe, Stephen; Pulgar, José; Miranda, Cristian; Jahnsen-Guzmán, Nicole; Quijón, Pedro A.
    Artificial light at night (ALAN) is a pervasive but still under-recognized driver of global change. In coastal settings, a large majority of the studies assessing ALAN impacts has focused on individual species, even though it is unclear whether results gathered from single species can be used to predict community-wide responses. Similarly, these studies often treat species as single life-stage entities, ignoring the variation associated with distinct life stages. This study addresses both limitations by focusing on the effects of ALAN on a sandy beach community consisting of species with distinct early- and late-life stages. Our hypothesis was that ALAN alters community structure and these changes are mediated by individual species and also by their ontogenetic stages. A field experiment was conducted in a sandy beach of north-central Chile using an artificial LED system. Samples were collected at different night hours (8-levels in total) across the intertidal (9-levels) over several days in November and January (austral spring and summer seasons). The abundance of adults of all species was significantly lower in ALAN treatments. Early stages of isopods showed the same pattern, but the opposite was observed for the early stages of the other two species. Clear differences were detected in the zonation of these species during natural darkness versus those exposed to ALAN, with some adult-juvenile differences in this response. These results support our hypothesis and document a series of changes affecting differentially both early and late life stages of these species, and ultimately, the structure of the entire community. Although the effects described correspond to short-term responses, more persistent effects are likely to occur if ALAN sources become established as permanent features in sandy beaches. The worldwide growth of ALAN suggests that the scope of its effect will continue to grow and represents a concern for sandy beach systems. © 2023