The sponge diversity of the eastern Canadian Arctic remains largely unknown. Sponges of the three marine ecoregions which make up the eastern Canadian Arctic and sub-Arctic are described from collections using remote operated vehicle (ROV), box core, and Agassiz trawl. In total, 161 sponges were collected between 2015 and 2017, and 60 different species were identified. ROV surveys covered a range of benthic habitats, but sponges seen in video could only be identified to morphotypes. Twenty-seven distinct sponge morphotypes were identified from ROV surveys of six sites in the study region, but only fifteen of these were commonly encountered and unambiguously identified at the different sites. Transects were carried out in a non-linear manner due to ROV limitations, and covered varied benthic habitats ranging from soft sand to steep bedrock cliffs. The highest number of species identified from specimens collected was in the Northern Labrador marine ecoregion (46 species), while the highest number of morphotypes identified from ROV video was in the Baffin Bay/Davis Strait ecoregion at a dive site near Pond Inlet (17 morphotypes). Several species collected and morphotypes counted were found across different ecoregions, but smaller sponges could not be identified from ROV video. Sponge density was estimated from exploratory ROV video and ranged from 0.008 ind. m−2 in Lancaster Sound to 0.371 ind. m−2 at a site near Pond Inlet. The combined collections and video analysis show the importance of using different collection and observation methodologies to properly understand the biodiversity of benthic habitats that are difficult to access.

中文翻译：

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加拿大东部北极地区的海绵群落：使用有针对性的底栖采样和水下视频分析确定的物种丰富度、多样性和密度

加拿大东部北极地区的海绵多样性在很大程度上仍然未知。组成加拿大东部北极和亚北极的三个海洋生态区的海绵是从使用遥控车辆 (ROV)、箱式核心和 Agassiz 拖网的集合中描述的。2015 年至 2017 年期间，共收集了 161 只海绵，并确定了 60 种不同的物种。ROV 调查涵盖了一系列底栖栖息地，但视频中看到的海绵只能被识别为形态类型。从研究区域的六个站点的 ROV 调查中确定了 27 种不同的海绵形态类型，但其中只有 15 种是常见的，并且在不同的站点中被明确识别。由于 ROV 的限制，横断面以非线性方式进行，覆盖了从软沙到陡峭基岩悬崖的各种底栖栖息地。从收集的标本中识别出的物种数量最多的是拉布拉多北部海洋生态区（46 种），而从 ROV 视频中识别出的形态类型数量最多的是位于池塘入口附近潜水点的巴芬湾/戴维斯海峡生态区（17 个形态类型） ）。在不同的生态区域中发现了几种收集的物种并计算了形态类型，但无法从 ROV 视频中识别出较小的海绵。海绵密度是根据探索性 ROV 视频估计的，范围为 0.008 ind。兰开斯特湾中的 m−2 至 0.371 ind。m−2 在池塘入口附近的站点。综合收集和视频分析显示了使用不同收集和观察方法正确了解难以进入的底栖栖息地生物多样性的重要性。