Factors limiting marine connectivity at a species' range edge - the case of the pink sea fan, Eunicella verrucosa

限制物种分布范围边缘海洋连通性的因素——以粉红海扇 Eunicella verrucosa 为例

• 批准号: 2784014
• 金额: --
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2784014
• 关键词: Factors; limiting; marine; connectivity; species

The pink sea fan, Eunicella verrucosa, is IUCN red-listed and is a protected species in UK waters. It is listed as a Protected Feature, a key factor in the designation of many of the MCZs designated in southwest England in 2013 and 2016. An understanding of the diversity and connectivity of this species is essential for both conservation of the species and the designation of further candidate MCZs (Natural England, 2016). We anticipate that this research will inform on both these key factors. The proposed project will investigate the extent of oceanographic pathways and barriers to gene flow, e.g. due to residual currents such as tidal mixing fronts and coastal/estuarine circulation patterns, and the role of selection in driving genetic differences between populations of pink sea fan at the northern limit of its range in southwest Britain. E. verrucosa is a broadcast spawner, with larvae reliant on oceanic currents for dispersal, and yet, to date, very little is known about the basic biology of this species, with little or no knowledge of its retention time in the water column or its ability to deal with thermal stress. Accordingly, we will undertake modelling and aquarium studies to begin to explore key biological factors that might be contributing to the lack of recruitment into these range edge populations. Obvious avenues for investigation include: heat stress, factors affecting spawning time, spawning duration, survival in the water column and pelagic larval duration. As these data become available these can subsequently be parameterised into our oceanographic models. High quality physical (currents, temperatures) and biological (e.g. population distributions, larval behaviour) data will be used to ground-truth the models, and a sensitivity framework will be designed to set the dispersal/connectivity results within uncertainties based on natural variability and model parameterisations. We hold at Exeter an extensive selection of sea fan tissue samples collected from across the species' range in the northeast Atlantic and the western Mediterranean and, critical to this proposal, we have now obtained permission to work with NRW staff at the Skomer Marine Reserve in Pembrokeshire, Wales, to take tissue samples from new recruits which have recently settled within the Skomer Marine Reserve. A key objective will be to establish whether the low level of recruitment of new sea fans at Skomer is due to connectivity, selection (possibly temperature, esp., minimum winter temperature), or whether (or to what extent) the Allee effect is acting, whereby the population density of mature adult fans is now so low (few fans, widely spaced) that the chances of gametes finding each other are reduced below an as yet unknown critical threshold. Findings for Skomer will be compared with those obtained at Lundy, a site at a similar latitude, but with potentially more robust in-water connectivity to major populations of pink sea fan in north and west Cornwall and the Isles of Scilly. We will use a molecular technique known as RAD-seq to identify single nucleotide polymorphism (SNPs) loci associated with particular geographical regions and/or with particular selection pressures. Our on-going project (Exeter) has recently finalised the screening of several thousand SNPs from across the pink sea fan genome - a panel of the most discriminating SNPs will be selected based on their ability to discriminate populations of interest (based on FST). In summary, the project offers a unique, trans-disciplinary research training for a postgraduate student with opportunities to gain experience in molecular genetics, oceanographic modelling and aquarium manipulations of sensitive marine organisims, generating results that will feed directly into UK marine policy through our CASE partner, Natural England, and our associate partner, Natural Resources Wales. Such a mix should deliver a highly skilled and employable young researcher.

粉红色的海风扇Eunicella verrucosa是IUCN红色上市，是英国水域受保护的物种。它被列为受保护的特征，这是指定在2013年和2016年在英格兰西南部指定的许多MCZ的关键因素。了解该物种的多样性和连通性对于该物种的多样性和连通性对于该物种的保护和指定的进一步候选MCZ至关重要（自然英格兰，2016年，2016年）。我们预计这项研究将为这两个关键因素提供信息。拟议的项目将研究海洋学途径的程度和基因流的障碍，例如由于残留的电流，例如潮汐混合前线和沿海/河口循环模式，以及选择在其西南英国范围的北部极限的粉红色海风扇种群驱动遗传差异中的作用。 E. verrucosa是一个广播产卵器，幼虫依靠海洋电流进行分散，但迄今为止，对该物种的基本生物学知之甚少，几乎没有知道其在水柱上的保留时间或处理热应力的能力。因此，我们将进行建模和水族馆研究，以开始探索可能导致缺乏招募这些范围边缘种群的关键生物学因素。显而易见的研究途径包括：热应力，影响产卵时间的因素，产卵持续时间，水柱中的存活率和上层幼虫持续时间。随着这些数据的可用，这些数据随后可以被参数化为我们的海洋模型。高质量的物理（电流，温度）和生物学（例如种群分布，幼虫行为）数据将用于基础模型，并且将设计一个灵敏度框架，以将基于自然变异性和模型参数的不确定性设置在不确定性中。我们在埃克塞特（Exeter）举行了广泛的选择，从该物种在东北大西洋和地中海西部的物种范围内收集的广泛选择，对于这一提议至关重要，我们现在已获得与NRW员工在威尔士彭布罗克郡（Pembrokeshire）的Skomer Marine Reserve合作的允许，以从新的Remeruits中获得Skomer severled seleds seled seleds seleds seleds seleds seleds seleds seleds sevens sevens seled seven new seven new seven sect s s s skomerar sermare seven sec sec secor sare pecter sears呢一个关键目标是确定在Skomer处招募新的海风扇的水平是否是由于连通性，选择（可能是温度，尤其是冬季温度，最低冬季温度），还是（或在多大程度上）合同的效果，因此成熟成年粉丝的人口密度现在是现在，现在很低（很少有粉丝，很少有个体的粉丝），以至于对每个人的机会很少。 Skomer的发现将与伦迪（Lundy）获得的发现（一个纬度类似的地点）进行了比较，但可能具有与北部和西康沃尔郡粉红色海风扇的主要种群和Scilly Isles的大量粉红色海风扇的内在连通性。我们将使用一种称为Rad-Seq的分子技术来识别与特定地理区域和/或与特定选择压力相关的单核苷酸多态性（SNP）基因座。我们正在进行的项目（埃克塞特）最近最终确定了从粉红色海洋风扇基因组中筛选数千个SNP的筛选 - 将根据其歧视感兴趣种群（基于FST）的能力来选择最有区别的SNP的小组。总而言之，该项目为研究生提供了独特的，跨学科的研究培训，有机会获得分子遗传学，海洋学建模和对敏感海洋组织的水族馆操纵的经验，从而产生结果，这些结果将通过我们的案例伙伴，自然英格兰和我们的同事合作伙伴，自然资源威尔士自然资源伙伴直接融入英国海洋政策。这样的组合应该提供高技能和可就业的年轻研究人员。