It is known that aquaculture may produce negative environmental effects on marine ecosystems. Southern Chile is one of the most important salmon and mussel-producing areas in the world. Here we assess the ecological status of benthic communities near farming centers in Caucahue Channel, Chiloe, which has been used intensely for salmon and mussel production for 30 years. The macrofauna, sediments and water column were characterized at distances of 5 to 100 m from three salmon and three mussel-producing centers. Information was also obtained from reference sites 500 to 3000 m from these aquaculture farms. The macrofauna and environmental conditions during winter were analyzed using uni- and multivariate analysis and the AZTI Marine Biotic Index (AMBI) as an indicator of benthic community condition. (i) There is a high degree of spatial dissimilarity in macrofauna and environmental variables among sampling sites and types of environments (far from or near farming centers) and between the northern and southern areas of the channel; (ii) sediment structure (mean grain size and percentage of total organic matter) correlated with the observed dissimilarities in macrofauna communities; and (iii) the level of perturbation according to AMBI was heterogeneous, with sites in the undisturbed/normal range to moderately disturbed/polluted. We found a high spatial dissimilarity in benthic macrofauna and environmental variables among sampling sites, environmental types and between the northern and southern areas of the channel. AMBI and multivariate community-environment analysis are useful tools to define the level of perturbation of a geographic area at different spatial scales, using all the ecological information from each sample and replicates.

中文翻译：

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大量用于水产养殖的奇洛埃岛海峡中大型动物群落模式：其底栖环境的生态状况

众所周知，水产养殖会对海洋生态系统产生不利的环境影响。智利南部是世界上最重要的鲑鱼和贻贝产区之一。在这里，我们评估了奇洛埃（Chiloe）Caucahue Channel养殖中心附近的底栖生物群落的生态状况，该鱼类已被大量用于鲑鱼和贻贝生产30年。在距三个鲑鱼和三个贻贝产地中心5-100 m的距离处，对大型动物，沉积物和水柱进行了表征。还从这些水产养殖场的500至3000 m的参考点获得了信息。使用单变量和多变量分析以及AZTI海洋生物指数（AMBI）作为底栖动物群落状况的指标，分析了冬季的大型动物和环境状况。（i）大型动物区系和环境变量在采样地点和环境类型之间（远离或靠近农作中心）以及该河道的北部和南部区域之间存在高度的空间差异；（ii）与大型动物群落中观察到的差异相关的沉积物结构（平均粒径和总有机质百分比）；（iii）根据AMBI的摄动水平是异类的，其位置在不受干扰/正常范围至中度受干扰/污染。我们发现底栖大型动物区系和采样点之间，环境类型之间以及河道南北区域之间的环境变量存在很大的空间差异。