ABSTRACT: Norwegian Atlantic salmon aquaculture is continuing to expand in northern regions dominated by hard- and mixed-bottom substrates. Such habitats contain rich benthic epifaunal communities, including sponges and other sessile invertebrates susceptible to the impacts of particulate material released from finfish farms. Here, conventional soft-sediment sampling techniques are unable to discern the impacts of farm waste, and new monitoring methods and indicator taxa must be identified. This study improves understanding of the impacts of particulate waste released from salmon farms on the density and structure of benthic epifaunal communities on mixed- and hard-bottom substrates. The diversity, density, and composition of epifaunal communities and visually conspicuous benthic infauna were recorded in towed camera transects along the enrichment gradient (~50-800 m) of 3 salmon farms in northern Norway. Elevated fluxes of particulate material in the vicinity of all farms significantly affected epifaunal community composition, as did the coverage of some key substrate types. The defecated mounds of lugworms and the seastar Asterias rubens were notably more abundant near the farms where fluxes were elevated. The sponges Polymastia spp. and Phakellia spp. and the soft coral Duva florida showed significant declines in density with increasing sedimentation and were principal taxa in communities at natural sedimentation levels. Results identify taxa with both positive and negative spatial associations to particulate waste released from finfish farms and the potential for the development of an epifauna indicator-based index for monitoring the environmental impacts of aquaculture in hard- and mixed-bottom dominated substrates.

中文翻译：

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硬底和混底底栖动物对挪威北部鲑鱼养殖有机富集的空间响应

摘要：挪威大西洋鲑鱼养殖在以硬底和混合底质为主的北部地区继续扩大。这些栖息地包含丰富的底栖动物群落，包括海绵和其他无柄无脊椎动物，它们容易受到有鳍鱼类养殖场释放的颗粒物质的影响。在这里，传统的软沉积物采样技术无法辨别农场废物的影响，必须确定新的监测方法和指标类群。这项研究提高了对鲑鱼养殖场释放的颗粒废物对混合和硬底基质上底栖动物群落密度和结构影响的理解。多样性、密度、在沿着挪威北部 3 个鲑鱼养殖场的富集梯度（~50-800 m）的拖曳相机横断面中记录了表层动物群落和视觉上显眼的底栖动物群的组成和组成。所有农场附近的颗粒物质通量升高显着影响了动物群落组成，一些关键基质类型的覆盖范围也是如此。沙虫和海星的粪便在通量升高的农场附近，Asterias rubens 的数量明显增多。海绵Polymastia spp。和Phakellia spp。软珊瑚Duva florida 的密度随着沉积的增加而显着下降，并且是自然沉积水平的群落中的主要分类群。结果确定了与有鳍鱼类养殖场释放的颗粒废物具有正负空间关联的分类群，以及开发基于表观动物群指标的指数以监测硬底和混底为主的基质中水产养殖对环境影响的潜力。