Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile; Laboratorio de Ecología y Conducta de La Ontogenia Temprana (LECOT), Coquimbo, Chile.
Laboratorio de Ecología y Conducta de La Ontogenia Temprana (LECOT), Coquimbo, Chile.
Environ Pollut. 2021 Jul 1;280:116895. doi: 10.1016/j.envpol.2021.116895. Epub 2021 Mar 15.
The growth of Artificial Light At Night (ALAN) is potentially having widespread effects on terrestrial and coastal habitats. In this study we addressed both the individual effects of ALAN, as well as its combined effect with predation risk on the behaviour of Concholepas concholepas, a fishery resource and a keystone species in the southeastern Pacific coast. We measured the influence of ALAN and predation risk on this mollusc's feeding rate, use of refuge for light and crawling out of water behaviour. These behavioural responses were studied using light intensities that mimicked levels that had been recorded in coastal habitat exposed to ALAN. Cues were from two species known to prey on C. concholepas during its early ontogeny: the crab Acanthocyclus hassleri and the seastar Heliaster helianthus. The feeding rates of C. concholepas were 3-4 times higher in darkness and in the absence of predator cues. In contrast, ALAN-exposed C. concholepas showed lower feeding activity and were more likely to be in a refuge than those exposed to control conditions. In the presence of olfactory predator cues, and regardless of light treatment, C. concholepas tended to crawl-out of the waterline. We provide evidence to support the hypothesis that exposure to either ALAN or predation risk can alter the feeding behaviour of C. concholepas. However, predator cue recognition in C. concholepas was not affected by ALAN in situations where ALAN and predator cues were both present: C. concholepas continued to forage when predation risk was low, i.e., in darkness and away from predator cues. Whilst this response means that ALAN may not lead to increased predation mortality in C. concholepas, it will reduce feeding activity in this naturally nocturnal species in the absence of dark refugia. Such results may have implications for the long-term health, productivity and sustainability of this keystone species.
人工夜间光照（ALAN）的增长可能对陆地和沿海生境产生广泛影响。在这项研究中，我们既研究了 ALAN 的单独影响，也研究了其与捕食风险的综合影响，以研究东南太平洋沿海地区的渔业资源和关键物种 Concholepas concholepas 的行为。我们测量了 ALAN 和捕食风险对这种软体动物摄食率、对光的避难所使用以及爬出水面行为的影响。使用模拟沿海生境中记录到的 ALAN 水平的光照强度来研究这些行为反应。这些线索来自两种已知在 Concholepas concholepas 早期发育阶段捕食它的物种：螃蟹 Acanthocyclus hassleri 和海星 Heliaster helianthus。在黑暗中和没有捕食者线索的情况下，C. concholepas 的摄食率要高出 3-4 倍。相比之下，暴露于 ALAN 下的 C. concholepas 的摄食活性较低，并且比暴露于对照条件下的更有可能处于避难所中。在存在嗅觉捕食者线索的情况下，无论光照处理如何，C. concholepas 都倾向于爬出水位线。我们提供的证据支持了这样一种假设，即暴露于 ALAN 或捕食风险都可以改变 C. concholepas 的摄食行为。然而，在 ALAN 和捕食者线索都存在的情况下，C. concholepas 对捕食者线索的识别不受 ALAN 的影响：当捕食风险较低时，即在黑暗中和远离捕食者线索时，C. concholepas 仍继续觅食。虽然这种反应意味着 ALAN 不会导致 C. concholepas 的捕食死亡率增加，但在没有黑暗避难所的情况下，它会降低这种自然夜间活动物种的摄食活性。这些结果可能对这种关键物种的长期健康、生产力和可持续性产生影响。
