Department of Biology, University of Prince Edward Island, Charlottetown, PE, Canada.
Facultad de Ciencias de la Vida and Centro de Investigaciones Marinas de Quintay, CIMARQ, Universidad Andrés Bello, Santiago, Chile; Programa de Doctorado en Medicina de la Conservación, Universidad Andrés Bello, Santiago, Chile.
Sci Total Environ. 2021 Aug 1;780:146568. doi: 10.1016/j.scitotenv.2021.146568. Epub 2021 Mar 19.
Artificial light at night (ALAN) is a growing source of stress for organisms and communities worldwide. These include species associated with sandy beaches, which consume and process stranded seaweeds (wrack) in these ecosystems. This study assessed the influence of ALAN on the activity and feeding behaviour of Americorchestia longicornis, a prominent talitrid amphipod living in sandy beaches of Prince Edward Island, Atlantic Canada. First, two parallel field surveys were conducted to document the natural daily cycle of activity of this species. Then, three related hypotheses were used to assess whether ALAN disrupts its locomotor activity, whether that disruption lasts over time, and whether it affects the feeding behaviour and growth of the amphipods. Tanks equipped with actographs recorded amphipod locomotor activity for ~7 days and then its potential recovery (after ALAN removal) for additional ~3 days. Separate tanks were used to compare amphipod food consumptions rates, absorption efficiency and growth rates under natural daylight / night (control) and altered conditions (ALAN). The results of these manipulations provide support to two of the three hypotheses proposed and indicate that ALAN was temporarily detrimental for (i.e. significantly reduced) the surface activity, consumption rates and absorption efficiency of the amphipods, whereas growth rates remained unaffected. The results also rejected the remaining hypothesis and suggest that the plasticity exhibited by these amphipods confer them the capacity to recover their natural rhythm of activity shortly after ALAN was removed from the system. Combined, these results suggest that ALAN has a strong, albeit temporary, influence upon the abundant populations of A. longicornis. Such influence has implications for the ecosystem role played by these amphipods as consumers and processors of the subsidy of stranded seaweeds entering these ecosystems.
人造夜间光（ALAN）是全球范围内生物体和群落的一个日益增长的压力源。这些包括与沙滩相关的物种，它们在这些生态系统中消耗和处理搁浅的海藻（海草）。本研究评估了 ALAN 对生活在加拿大大西洋省爱德华王子岛沙滩上的一种突出的沙蚤科桡足类动物 Americorchestia longicornis 的活动和摄食行为的影响。首先，进行了两项平行的野外调查，以记录该物种自然的日常活动周期。然后，使用三个相关假设来评估 ALAN 是否会扰乱其运动活动，这种干扰是否会随时间持续，以及它是否会影响桡足类动物的摄食行为和生长。配备活动记录仪的水箱记录了大约 7 天的桡足类动物的运动活动，然后记录了它们在 ALAN 去除后的潜在恢复（额外的大约 3 天）。使用单独的水箱比较了在自然光/夜间（对照）和改变条件（ALAN）下桡足类动物的食物消耗率、吸收率和生长率。这些操作的结果支持了提出的三个假设中的两个，并表明 ALAN 暂时对（即显著降低）桡足类动物的表面活动、消耗率和吸收率有害，而生长率不受影响。结果还否定了剩余的假设，并表明这些桡足类动物表现出的可塑性使它们有能力在 ALAN 从系统中去除后不久恢复其自然活动节律。综合来看，这些结果表明 ALAN 对丰富的 A. longicornis 种群有强烈的影响，尽管这种影响是暂时的。这种影响对这些桡足类动物作为进入这些生态系统的搁浅海藻的消费者和处理者的生态系统作用具有重要意义。
