The influence of Larsen-C ice-cover on macrobenthic peracarid crustacean assemblages on the Antarctic shelf

2017年7月12日，拉森-c冰架崩解了有史以来最大的冰山（A68），使5800平方公里的海底重新暴露在开阔的海洋环境中，这些海底很可能在几个世纪甚至自上次间冰期以来一直被冰覆盖。这使我们能够解决与气候变化下极地大陆架的可持续性有关的基本问题，底栖生物种群迁移的过程，以及海洋底栖生物的分布可以用来解释过去对气候变化的反应的程度。直到Larsen-A和B冰架消退后的第5年和第12年才开始对生物多样性进行研究。拉森- c珍珠项目现在将在2018年2月/ 3月从RSS詹姆斯克拉克罗斯董事会开始大规模殖民化之前调查新暴露的大陆架。2019年，该地区还将从RV北极星号的板上取样，这将是极地研究中第一次能够尽早在前冰雪覆盖地区下方生成生物多样性、底栖生物群落组成、物种周转和定居、营养结构的基线描述。这项研究将是预测底栖生物系统对未来冰架进一步崩塌影响的反应的关键，并提高对极地大陆架生态系统恢复力的基本认识，为有效的生态系统管理法规提供支持。该项目的主导假设是：“在拉森- c冰山A68崩解之前，冰架下海床上的底栖动物群可能由类似深海威德尔海的寡营养组合组成。A68的产犊，以及海床暴露在开阔的海洋和海冰条件下，将启动新物种的快速殖民，这将在短时间内显著改变底栖生态系统。“拉森- c珍珠”将专注于过表层甲壳类动物，并遵循四个主要目标：1。浅海和超浅海过表层甲壳类生物多样性及组合结构评价2. Larsen-C地区超干旱物种的分类描述及其系统地理重建3. 将Larsen-C第1年的生物多样性和过表层组合结构（2019年PS 118考察）与第0年和其他地区（例如Filchner海槽和无冰的南奥克尼群岛以及威德尔海的深海）进行比较，以调查转移、殖民和/或继承；4. Larsen-C冰架下产犊后第0年和次年及无冰区之间过冰官能团的鉴定。

On 12 July 2017, the Larsen-C Ice Shelf calved the largest iceberg (A68) originating from the Antarctic Peninsula ever recorded leaving 5,800 km² of seabed newly exposed to open-marine conditions which had very likely remained ice-covered for centuries or even since the last inter-glacial period. This enables us to address fundamental questions relating to the sustainability of polar continental shelves under climate change, the processes by which benthic populations migrate, and the degree to which the distribution of marine benthos can be used to interpret past responses to climate change. Biodiversity was not studied until 5 and 12 years respectively after the retreats of Larsen-A & B ice shelves. The Larsen-C Pearl project will now investigate the newly exposed shelf before significant colonisation begins from board of the RSS James Clarke Ross in February/March 2018. In 2019 this area will also be sampled from board of the RV Polarstern and it will be able for the first time in polar research to generate a baseline description of biodiversity, benthic community composition, species' turnover and colonisation, trophic structure at the very earliest opportunity underneath a former ice-covered area. This research will be key to producing predictions of the benthic systems’ response to future impacts on further ice-shelf collapse and improve fundamental understanding about the resilience of polar continental shelf ecosystems for a support of effective ecosystem management regulations.The project’s governing hypothesis is: "Until the calving of the Larsen-C iceberg, A68, the benthic fauna on the seabed beneath ice shelf has likely comprised oligotrophic assemblages resembling deep-sea Weddell Sea assemblages. The calving of A68, and the exposure of the seabed to open-marine and sea-ice conditions will initiate a rapid colonisation by new species that will transform the benthic ecosystem significantly within a short timeframe."Larsen-C Pearl will focus on peracarid crustaceans and follow four major objectives: 1. Biodiversity and assemblage structure assessment of the epi- and suprabenthic peracarid crustaceans; 2. Taxonomic descriptions of the selected peracarid species discovered in the Larsen-C area and reconstruction of their phylogeography; 3. Comparison of Larsen-C Year-1 biodiversity and peracarid assemblage structure (PS 118 expedition in 2019) with Year-0 and other areas (e.g. Filchner Trough and the ice free South Orkney Islands as well as deep sea of the Weddell Sea) to investigate turn-over, colonisation and/or succession; 4. Identification of peracarid functional groups beneath the Larsen-C ice shelf in year-0 and the next year after the calving and between ice-free areas.