Artificial light at night (ALAN) is an anthropogenic pollutant that is intensifying and expanding in marine environments, but experimental studies of community‐level effects are generally lacking. The inshore, shallow, and clear‐water locations of coral reefs and their diverse photosensitive inhabitants make these ecosystems highly susceptible to biological disturbances; at the same time, their biodiversity and accessibility make them model systems for wider insight. Here, we experimentally manipulated ALAN using underwater LED lights on a Polynesian reef system to investigate the influence on localised nighttime fish communities compared to control sites without ALAN. We collected infrared video censuses of baseline communities prior to manipulation, which we repeated following short‐term (mean of three nights) and prolonged (mean of 25 nights) exposures to ALAN. Short‐term ALAN exposure did not induce any significant alterations to the nighttime fish community, but prolonged ALAN exposure increased nighttime species richness. Species compositions exposed to prolonged ALAN were more dissimilar from their baseline compared to control sites. The difference between community compositions at prolonged ALAN exposure and control sites was not apparent at the family level; instead, it was observed from the composition of trait guilds. Following prolonged ALAN exposure, more diurnal and nocturnal predatory species (piscivores, invertivores, and planktivores)—particularly those that are site‐attached or mobile within reefs—were present in nighttime assemblages. Our experimental findings show that coastal ALAN could cause trophic imbalances and circadian disturbances in localised nighttime reef fish communities. Given that community‐wide consequences were only apparent after prolonged ALAN exposure suggests that management of the duration of artificial lighting could potentially be used to reduce impacts on marine ecosystems.

中文翻译：

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人造光增加了夜间掠食性鱼类的普遍性，改变了珊瑚礁的群落组成


夜间人造光 （ALAN） 是一种人为污染物，在海洋环境中正在加剧和扩大，但通常缺乏对社区层面影响的实验研究。珊瑚礁的近海、浅水和清水位置及其多样化的光敏居民使这些生态系统极易受到生物干扰;同时，它们的生物多样性和可及性使它们成为更广泛见解的模型系统。在这里，我们在波利尼西亚珊瑚礁系统上使用水下 LED 灯实验操纵 ALAN，以研究与没有 ALAN 的对照地点相比，对局部夜间鱼类群落的影响。我们收集了操作前基线社区的红外视频普查，我们在短期 （平均 3 晚） 和长期 （平均 25 晚） 暴露于 ALAN 后重复进行。短期 ALAN 暴露不会对夜间鱼类群落造成任何重大改变，但长时间暴露 ALAN 会增加夜间物种丰富度。与对照位点相比，暴露于长时间 ALAN 的物种组成与其基线更不同。在家庭水平上，长期 ALAN 暴露部位和对照部位的群落组成差异不明显;相反，它是从 trait guilds 的组成中观察到的。在长时间暴露于 ALAN 之后，更多的昼夜和夜间捕食性物种（食鱼动物、无脊椎动物和浮游动物）——特别是那些附着在珊瑚礁内或在珊瑚礁内移动的物种——出现在夜间组合中。我们的实验结果表明，沿海 ALAN 可能导致局部夜间珊瑚鱼群落的营养失衡和昼夜节律紊乱。 鉴于整个社区的后果只有在长时间暴露后才会显现出来，这表明对人工照明持续时间的管理有可能用于减少对海洋生态系统的影响。