Assessing the threat to Antarctic shallow marine ecosystems from hitchhikers on non-native kelp

评估非本地海带搭便车者对南极浅海生态系统的威胁

• 批准号: 2889815
• 金额: --
• 依托单位: University of Hull
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2889815
• 关键词: Assessing; threat; Antarctic; shallow; marine

Human activity and shipping have long been considered the principal threats to the "biosecurity" of the remote and isolated shallow marine ecosystems of Antarctica (Chown et al., 2015). However, recent work has shown that the Southern Ocean's strong, circumpolar winds, currents and fronts may not be a barrier to natural colonisation from the north (Fraser et al., 2018). The sub-Antarctic (Patagonia, the Falkland Islands, New Zealand and the mid-latitude islands of the Southern Hemisphere) shallow water marine environment is often characterised by highly exposed shores on extremely remote islands (Griffiths & Waller, 2016). The ice-free coastlines are often dominated by dense beds of the kelp Durvillaea antarctica, Macrocystis pyrifera and other large macrophytes. Antarctic shallow coastal marine communities were long thought to be isolated from their subAntarctic neighbours by hundreds of kilometres of deep ocean and the Antarctic Circumpolar Current.According to the literature, over 70 million kelp rafts are afloat in the Southern Ocean at any one time (Smith, 2002). These living, floating islands can play host to a range of passenger species from both their original coastal location and those picked in the open ocean. Driven by winds, currents and storms towards the coast of the continent, these rafts are often cited as theoretical vectors for the introduction of new species into Antarctica and the sub-Antarctic islands.Our discovery of non-native kelp and a wide range of 'hitchhiking' passenger organisms washed up on Antarctic beaches led us to question the permeability of these barriers to species dispersal (Avila et al., 2020). This is the first evidence of non-native species reaching the Antarctic continent alive on kelp rafts. One passenger species, the bryozoan Membranipora membranacea, is found to be an invasive and ecologically harmful species in some cold-water regions, and this is its first record from Antarctica (Avila et al., 2020).The successful applicant will investigate the communities found on floating and beached kelp from southern Chile, the Falkland Islands, South Georgia and Antarctica using existing data and samples, opportunistic collections by scientific expeditions (including partners from University of Barcelona on the Spanish National Antarctic Expeditions), tourist vessels and previous expeditions. The candidate will be expected to undertake a field campaign to the South Atlantic to quantify the potential hitchhikers and conduct physiological experiments. They will be working with collaborators/partners in Chile (University of Magallanes) and the CASE partner in the Falkland Islands (South Atlantic Environmental Research Institute - SAERI).The candidate will:Identify the species living on the two main species of kelp in the region, Durvillaea antarctica and Macrocystis pyrifera, and their abundance and location on the kelp plants.Examine the effect of kelp becoming dislodged from the shore on the fauna and flora that live on the kelp, simulating the effects of storms that lead to kelp rafting (undertaken using scuba diving in the Falkland Islands and potentially in Magellanic Chile).Investigate biogeographic distribution patterns in the species living on the kelp, using taxonomic and molecular methods; and relating this to oceanographic models and the role of kelp as a vector.Understanding the ability of sub-Antarctic and Falkland Island native species to tolerate conditions found south of the Polar Front both now and in the future (using physiological experiments and IPCC climate scenarios).Undertake a risk assessment, using knowledge gained from the PhD, to inform scientists and policy makers about the likely candidate species and centres of colonisation south of the Polar Front, both now and in the future.

长期以来，人类活动和航运一直被认为是对南极洲偏远和孤立的浅海生态系统“生物安全”的主要威胁（Chown等人，2015年）的报告。然而，最近的研究表明，南大洋强大的绕极风、洋流和锋面可能不会成为来自北方的自然殖民的障碍（Fraser等人，2018年）。亚南极（巴塔哥尼亚，福克兰群岛，新西兰和南半球中纬度岛屿）浅水海洋环境的特点通常是在极其偏远的岛屿上高度暴露的海岸（Griffiths & Waller，2016）。无冰的海岸线通常被密集的海藻Durvillaea anastritica，Macrocystis pyrifera和其他大型水生植物所占据。长期以来，人们一直认为，南极浅海沿岸海洋群落与其亚南极的邻居被数百公里深的深海和南极绕极洋流隔离开来，根据文献，任何时候都有7 000多万只海带筏漂浮在南大洋上（Smith，2002年）。这些活的漂浮岛屿可以招待一系列来自原始沿海地区和公海的乘客物种。在风、海流和风暴的推动下，这些木筏向大陆海岸移动，通常被认为是将新物种引入南极洲和亚南极岛屿的理论载体。我们发现了非本土的海带和被冲上南极海滩的各种“搭便车”的乘客生物，这使我们质疑这些屏障对物种扩散的渗透性（阿维拉等人，2020年）。这是第一次有证据表明非本地物种在海带筏上活着到达南极大陆。一个过客物种，苔藓虫膜孔苔虫，被发现是一些冷水区的入侵和生态有害物种，这是它在南极洲的第一个记录（阿维拉等人，2020).成功的申请者将利用现有数据和样本、科学考察队（包括西班牙国家南极考察队巴塞罗那大学的合作伙伴）、旅游船只和以前的考察队的机会性收集，调查在智利南部、福克兰群岛、南格鲁吉亚和南极洲漂浮和搁浅的海带上发现的群落。预计候选人将在南大西洋进行实地考察，以量化潜在的搭便车者并进行生理实验。他们将与智利的合作者/伙伴合作（马加拉内斯大学）和CASE在福克兰群岛的合作伙伴（南大西洋环境研究所）。确定生活在该地区两种主要海带上的物种，Durvillaea anatomitica和Macrocystis pyrifera，以及它们在海带植物上的丰度和位置。研究海带从海岸脱落对生活在海带上的动物和植物群的影响，模拟风暴对海带漂流的影响（在福克兰群岛和可能在麦哲伦智利进行水肺潜水）利用分类学和分子生物学方法，调查生活在海带上的物种的地理分布模式;并将其与海洋学模型和海带作为载体的作用联系起来。了解亚-南极和福克兰群岛的本地物种现在和将来都能忍受极地锋以南的条件（利用生理学实验和IPCC气候情景）。利用博士获得的知识进行风险评估，向科学家和政策制定者提供关于现在和将来极锋以南可能的候选物种和殖民中心的信息。