Benthic communities are responding to rapid environmental change in the Arctic, yet the ecologically important meiofauna remain poorly studied, leaving little baseline information for evaluating such changes. We investigated the community structure of meiofaunal nematodes (> 63 µm) on the Northeast Chukchi Sea (NEC) continental shelf (< 50 m), and along a broad longitudinal and bathymetric gradient in the Beaufort Sea (BEAU; 20–1200 m). In total, 139 nematode genera representing 32 families were identified. Nematode communities differed between the NEC and BEAU, but the opportunistic genera Sabatieria (Comesomatidae) and Daptonema (Xyalidae) were abundant in both seas. Despite the relatively small sampling area of similar depth across the NEC, spatial variation was reflected by the high abundance of Sabatieria at a subset of sites with higher proportion of fine sediment. Nematode communities in the western BEAU offshore of the Colville River showed little difference among depths, in contrast to areas further east where shelf and upper slope communities were more distinct. Diversity indices were higher in the BEAU than in the NEC, with maximum values in the easternmost area (Banks Island); lower evenness was recorded in the western BEAU (Colville Plume), which was dominated by Sabatieria at all depths. Organic matter quality and quantity influenced community structure in the BEAU. This study provides the first genus-level characterization of nematode communities across this environmentally heterogeneous region. With increased exploration for natural resources and reduced ice coverage, the baseline community structure information provided here supports evaluation of ecosystem change in the Arctic.

北极的底栖动物群落正在对迅速的环境变化作出反应，但是对生态重要的动物群的研究仍然很少，几乎没有用于评估这种变化的基准信息。我们调查了东北楚科奇海（NEC）大陆架（<50 m）以及波弗特海（BEAU; 20–1200 m）沿宽广的纵向和测深梯度，其淡紫色线虫（> 63 µm）的群落结构。总共鉴定出代表32个科的139个线虫属。NEC和BEAU之间的线虫群落有所不同，但是机会性属Sabatieria（Comesomatidae）和Daptonema（Xyalidae）在两个海中都丰富。尽管整个NEC的相似深度的采样面积相对较小，但沙巴氏菌的高丰度却反映了空间变化，沙巴氏菌在细沉积物比例较高的子集的一部分位置上较高。与位于更东部的陆架和上坡群落更为明显的地区相比，科尔维尔河近岸的BEAU西部的线虫群落在深度上几乎没有差异。BEAU的多样性指数高于NEC，在最东部的区域（班克斯岛）最高。西部BEAU（Colville Plume）记录到较低的均匀度，该区域以萨巴地亚为主导在所有深度。有机物的质量和数量影响了BEAU的群落结构。这项研究提供了该环境异质区域中线虫群落的第一个属水平特征。随着自然资源勘探的增加和冰覆盖面积的减少，此处提供的基准群落结构信息支持对北极生态系统变化的评估。