Recent research has illuminated biological processes taking place during the polar night in the high Arctic, while simultaneously, the polar regions are undergoing rapid climate-driven change. There is a pressing need for research to establish baseline conditions and understand the influence of oceanographic factors on polar communities. We collected plankton samples in Kongsfjorden (Svalbard, Arctic) in January 2020, in order to study the early life-history stages of benthic invertebrates during the polar night. Specimens were identified using morphology and DNA barcoding. During our field campaign, a strong wind event occurred, which caused upwelling of Arctic water in the fjord. Therefore, we also investigated the influence of oceanographic factors on benthic invertebrate larvae, including temperature, salinity, and depth. Our samples included 19 different species or morphotypes belonging to ten invertebrate phyla, including three embryo morphotypes. The collection of embryos indicates that at least some taxa are reproducing in the polar night. Larval community structure at shallow stations was significantly different before and after the upwelling event. Our samples also reflected patchiness in the larval community and a significant influence of depth. The most common nutrition mode among the larval taxa we collected was lecithotrophy (energy derived from maternal yolk), but we also collected a few taxa that may be planktotrophic (feeding). Development via lecithotrophy could increase larval survival and settlement success in the low-food environment of the Arctic winter. This study provides essential data on the early life-history stages of benthic invertebrates in an understudied season.

最近的研究阐明了北极高地极夜期间发生的生物过程，与此同时，极地地区正在经历气候驱动的快速变化。迫切需要进行研究以建立基线条件并了解海洋因素对极地群落的影响。我们于 2020 年 1 月在 Kongsfjorden（斯瓦尔巴群岛，北极）收集了浮游生物样本，以研究极夜期间底栖无脊椎动物的早期生活史阶段。使用形态学和 DNA 条形码识别标本。在我们的野外活动期间，发生了强风事件，导致峡湾中的北极海水上升。因此，我们还研究了海洋因素对底栖无脊椎动物幼虫的影响，包括温度、盐度和深度。我们的样本包括属于 10 个无脊椎动物门的 19 个不同物种或形态类型，包括三个胚胎形态类型。胚胎的收集表明，至少有一些分类群在极夜繁殖。浅水站幼虫群落结构在上升流事件前后有显着差异。我们的样本还反映了幼虫群落的斑驳性和深度的显着影响。我们收集的幼虫类群中最常见的营养模式是卵磷脂（来自母体蛋黄的能量），但我们也收集了一些可能是浮游生物（摄食）的类群。通过卵磷脂的发育可以增加幼虫在北极冬季的低食物环境中的存活率和定居成功率。