The role of pelagic foodfalls in subsidizing deep-sea bottom communities in a changing ocean

深海是地球上最大的环境，是碳的汇，也是未开发的生物多样性储藏库。在我们对如何维持深海区域以及深海社区如何受到气候变化和其他人类压力的影响的理解上存在很大差距。该项目结合了深海采样和实验、实验室分析以及独特的现场观测数据库的分析，以调查深海中上层和底栖碳通量、生物多样性和食物网之间的联系。它将建立对研究和预测气候变化和人类压力对深海群落及其生物多样性的影响至关重要的基本知识。第一部分存在于许多海洋碳收支中的一个生态悖论是，通过沉积物捕获器测量的到达海底的有机物的数量不能解释许多海底群落的呼吸速率和生物量。我将检验一个假设，即中等大小(无脊椎动物)的食物降雨量可以部分解释地区碳预算的差距。我将利用现有的深海海底观测数据库，并通过在海洋探险期间进行海底调查，来描述和量化北极、北大西洋和北太平洋的天然食物。为了帮助检测消耗的食物，我将分析深海沉积物中的环境DNA，以鉴定Nekton和大型大型浮游动物的Edna。第二部分为了验证大型无脊椎动物食物瀑布是深海生物多样性驱动力的假设，该项目将在北极、太平洋和大西洋进行诱饵着陆器实验，比较鱼类、头足类和大型胶状浮游动物腐肉之间的觅食群落和演替阶段以及处理时间。这些信息将有助于预测营养层叠和范围扩大导致的中上层群落的变化如何改变底栖觅食群落的多样性和碳分布。第三部分我们将在长期生态研究(LTER)站点HAUSGARTEN建立远洋基线，以调查气候变化热点地区远洋腐肉物种的组成、丰度和分布。北极远洋基线将与太平洋和大西洋现有的远洋动物基线进行比较，并将作为一个起点，以描绘快速变化的(北极)海洋的海底和远洋环境之间的耦合。

The deep sea is the largest environment on the planet, a sink for carbon and an unexplored biodiversity reservoir. Large gaps exist in our understanding of how the deep regions of the oceans are sustained and how deep-sea communities are impacted by climate change and other human pressures. This project combines deep-sea sampling and experiments, laboratory analyses, and the analysis of unique databases of in situ observations to investigate the link between deep-sea pelagic and benthic carbon flux, biodiversity and food-webs. It will establish basic knowledge that is essential to study and predict the effect of climate change and human pressures on deep-sea communities, and their biodiversity. Part I An ecological paradox that exists in many ocean carbon budgets is that the amount of organic matter that reaches the seafloor, as measured by sediment traps, cannot explain the respiration rates and biomass of many benthic communities. I will test the hypothesis that medium size (invertebrate) foodfalls can explain part of the gap in regional carbon budgets. Using existing databases of deep seafloor observations and by performing benthic surveys during ocean expeditions, I will characterize and quantify natural foodfalls in the Arctic, North Atlantic and North Pacific. To aid the detection of consumed foodfalls, I will analyze environmental DNA in deep-sea sediment to qualify eDNA of nekton and large macrozooplankton. Part II To test the hypothesis that large invertebrate foodfalls are drivers of biodiversity in the deep ocean, this project will perform baited lander experiments in the Arctic, Pacific and Atlantic comparing the scavenging communities and successional stages, as well as processing time, between carrion of fish, cephalopods, and large gelatinous zooplankton. This information will serve to predict how changing pelagic communities as a result of trophic cascades and range expansion may alter diversity and carbon distribution by benthic scavenging communities. Part III We will establish a pelagic baseline at the LTER (Long-term Ecological Research) site HAUSGARTEN to investigate the composition, abundance and distribution of pelagic carrion species in a hotspot of climate change. The Arctic pelagic baseline will be compared to existing baselines of pelagic fauna in the Pacific and Atlantic, and will serve as a starting point to delineate the coupling between the benthic and pelagic environments in a rapidly changing (Arctic) ocean.