Climate change in the deep sea: assessing the resilience of deep-sea communities

深海栖息地覆盖地球表面的60%，是地球上最大和最少探索的环境。深海生物群落依靠表层海洋的初级生产维持，对供应的变化很敏感。气候变化正在减少深海海底的食物供应，生物量大幅下降。这个博士将使用30年的深海时间序列来探索社区如何应对食物供应的变化，并结合联合收割机经验测量，理论和建模，以更好地了解能量流和生态系统function.ObjectivesThis博士将集中在三个主要问题：1）如何深海食物网应对气候引起的食物供应的变化？您将使用从豪猪深海平原（PAP）收集的动物群的稳定同位素组成来记录饮食变化;并在数值/模型框架中使用这些数据将营养生态学与生态系统能量流联系起来。3）所产生的数据将用于进一步制定现有的生物多样性指标和目标，以评估气候变化对深海生物多样性和食物网的影响，在英国对良好环境状况进展的评估中确定的一个关键知识差距（2019年）。新颖性这个博士学位是一个令人兴奋的机会，可以探索如何深入-海洋生态系统对气候引起的食物供应变化作出反应。您将获得以下经验：1.深海取样和时间序列分析（前往太平洋行动计划持续观测站的研究航行）;2.无脊椎动物识别、稳定同位素分析和建模;3.将研究转化为基于政策的工具，以评估气候变化对英国深海环境的影响（JNCC安置）。及时性该项目的成果对深海海底生态系统监测和保护具有重要影响。深海海底栖息地覆盖约60%的地球表面，其生态系统与上层水过程密切相关。深海（约3 000米至6 000米）底栖生物群落由地表水初级生产维持，因此对这种食物供应的变化很敏感。然而，气候变化的影响正在减少这些社区获得的食物数量。位于东北大西洋的豪猪深海平原持续观测站是一个时间序列站点，拥有30多年的数据，重点关注表层和深海之间的联系。目前的博士项目将利用这些数据来探索该地区的社区如何应对气候引起的食物供应变化，这将对深海底栖生态系统的监测和保护产生重要影响。将从豪猪深海平原收集大型底栖动物，并与以前收集的标本一起进行分析，以计算其稳定同位素组成。这些将用于确定生物体饮食的任何变化。稳定同位素比率将被检查，以确定它们如何随身体大小而变化，并用于数值模型中，将营养生态学与生态系统能量流联系起来。生态特征，如繁殖力和物种丰富度，也将被检查，以确定它们是如何与食物供应。生成的数据将用于确定食物供应减少如何影响深海海底的底栖生物量，从而评估气候变化对深海生物多样性和食物网的影响。最终，该研究将制定现有的生物多样性指标和目标，并将转化为政策工具，以评估气候变化对英国深海环境的影响。

Deep-sea habitats cover ~60% of the Earth's surface and are the largest and least explored environment on the planet. Deep-sea communities are sustained by primary production from the surface ocean and are sensitive to changes in its supply. Climate change is reducing food supply to the deep seafloor, with a substantial decline in biomass. This PhD will use a 30-year abyssal time series to explore how communities respond to changes in food supply, and combine empirical measurements, theory, and modeling to better understand energy flow and ecosystem function.ObjectivesThis PhD will focus on three main questions:1) How do deep-sea food webs respond to climate-induced changes in food supply? You will document changes in diet using the stable isotopic composition of fauna collected from the Porcupine Abyssal Plain (PAP); and use those data in numerical/model frameworks to link trophic ecology to ecosystem energy flows.2) Do changes in food supply affect biological and ecological traits? You will include an examination of how body size, trophic indices, fecundity, species richness, are related to food supply.3) The data generated will be used to further develop existing biodiversity indicators and targets to assess the impact of changing climate on deep-sea biodiversity and food webs, a key knowledge gap identified in the UK's assessment of progress towards Good Environmental Status (2019).NoveltyThis PhD is an exciting chance to explore how deep-sea ecosystems respond to climate-induced changes in food supply. You will gain experience in:1. deep-sea sampling and time series analyses (research cruise to PAP Sustained Observatory);2. invertebrate identification, stable isotope analysis and modelling;3. translating research into policy-based tools to assess the impacts of climate change on UK deep-sea environments (JNCC placement).TimelinessThe outcomes of the project have important implications for deep-sea benthic ecosystem monitoring and conservation.Deep sea-floor habitats cover about 60% of the Earth's surface, and their ecosystems are intimately connected to upper-water processes. Abyssal (~3000m - 6000m) benthic communities are sustained by surface water primary production and are therefore sensitive to changes in this food supply. However, the impacts of climate change are reducing the quantity of food that reaches these communities. The Porcupine Abyssal Plain Sustained Observatory in the NE Atlantic Ocean is a time-series site with over 30 years of data, focusing on the connections between the surface and deep ocean. The current PhD project will use this data to explore how communities at this location respond to climate-induced changes in food supply, and it will have important implications for deep-sea benthic ecosystem monitoring and conservation. Benthic macrofauna will be collected from the Porcupine Abyssal Plain and analysed alongside previously collected specimens to calculate their stable isotopic compositions. These will be used to determine any changes in the organism's diets. Stable isotope ratios will be examined to determine how they change with body size, and used in numerical models to link trophic ecology to ecosystem energy flows. Ecological traits, such as fecundity and species richness, will also be examined to determine how they are related to food supply. The data generated will be used to determine how reduced food supply impacts benthic biomass at the abyssal seafloor, thus assessing the impacts of a changing climate on deep-sea biodiversity and food webs. Ultimately, the research will develop existing biodiversity indicators and targets, and will be translated into policy tools to assess the impacts of climate change on UK deep-sea environments.