Collaborative Research: Improving quantification of larval dispersal in the global coastal ocean to understand the genetic structure, biogeography, and spread of benthic organisms

许多海洋物种的后代或幼体被洋流携带或传播。这种扩散影响了物种的生存地点，它们在空间中的遗传变异性，以及它们如何随着气候变化传播到新的地点。该项目使用全球洋流的现代模型来量化这种扩散，并探索洋流如何影响它。这种方法的新奇来自模拟洋流及其可变性的高空间分辨率。扩散的详细估计进行比较，观察到的途径漂流和对物种分布和遗传变异的信息。大多数先前的努力忽略了洋流来估计传播，而是使用后代在水中漂浮的时间。事实上，当考虑洋流时，主要关注的是从近海向海岸运送幼虫，而不是沿着海岸运输。 该项目解决了这两个不足之处，并使在全球范围内的沿海物种空间分布的扩散的影响进行检查。该项目包括开发软件工具和数据集，沿着培训视频，使研究人员、生态系统管理人员、环境机构和其他感兴趣的各方能够自行模拟不同日期和地点的扩散。两名博士和六名本科生正在接受科学职业培训，让他们开发相关的跨学科调查，从海洋生态学到数值建模和物理海洋学。该项目使用现代高分辨率全球模型来解释沿海海洋物种的幼虫扩散如何定量地影响全球沿海海洋的生态地理学、生物地理学和可入侵性。该项目的创新之处在于，根据现有的大规模数据集，对沿岸扩散，包括洋流的大小和空间变异性进行了海洋学上的现实估计。产品包括使研究界能够容易地估计幼虫沿着全球海洋海岸分布的工具，取代了迄今为止占主导地位的粗略的、往往是不正确的估计。从墨卡托1/12度数据同化全球环流模式的电流计算的扩散路径进行了验证，从全球漂流物项目的表面漂流物数据。这种新的扩散数据是用来确定沿岸变化的作用，在幼虫扩散1）的遗传估计的连接，2）地理边界的位置，和3）在世界各地的开放海岸线的易感性的变化，以入侵物种与浮游幼虫。这项研究改进了以往的研究，通过量化的距离幼虫沿岸运输的洋流在近海幼虫池，允许检查扩散如何影响空间结构内和物种之间在全球范围内。对海洋学对扩散的影响进行全球性、基于地点的量化，加深了对海流在物种分布中所起作用的理解。反过来，了解扩散重要性的区域差异有助于预测物种对变化条件的区域特定反应。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The offspring or larvae of many marine species are carried or dispersed by ocean currents. This dispersal impacts where species persist, their genetic variability in space, and how they can spread to new locations as climate changes. This project uses a modern model of global ocean currents to quantify this dispersal and to explore how currents affect it. The novelty of this approach comes from the high spatial resolution of the simulated currents and their variability. The detailed estimates of dispersal are compared to observed pathways traveled by drifters and against information of species distributions and of their genetic variability. Most prior efforts ignored ocean currents to estimate dispersal, using instead the time that offspring are floating in the water. When the ocean currents were in fact considered, the delivery of larvae to the coast from offshore was the main focus, rather than transport occurring along the shore. This project addresses both deficiencies and enables examination of the effect of dispersal on the distribution of coastal species space at a global scale. The project includes the development of software tools and data sets, along with training videos, that allow researchers, ecosystem managers, environmental agencies, and other interested parties to model dispersal for different dates and locations on their own. Two PhD and six undergraduate students are being trained for scientific careers by having them develop related inter-disciplinary investigations, spanning from marine ecology to numerical modeling and physical oceanography. This project uses a modern high-resolution global model to explain how larval dispersal of coastal marine species quantitatively affects the biogeography, phylogeography, and invasibility of coastal oceans globally. The project is innovative in that oceanographically realistic estimates of alongshore dispersal, including the magnitude and spatial variability of ocean currents, are tested against existing large-scale datasets. Products include tools that allow the research community to easily estimate the dispersal of larvae along the coast of the global ocean, replacing the crude, and often incorrect, estimates that have dominated approaches to date. Dispersal paths calculated with currents from the Mercator 1/12 degree data-assimilative global circulation model are validated against surface drifter data from the Global Drifter Project. This new dispersal data is used to determine the role of alongshore variation in larval dispersal on 1) the magnitude of genetic estimates of connectivity, 2) the location of biogeographic boundaries, and 3) the variation in susceptibility of open coastlines around the world to invasive species with planktonic larvae. This study improves on previous studies by quantifying the distance larvae are transported alongshore by ocean currents in the offshore larval pool, allowing an examination of how dispersal affects spatial structuring within and among species at a global scale. Global, place-based quantification of the influence of oceanography on dispersal deepens the understanding of the role currents play in species distributions. In turn, understanding the regional differences in the importance of dispersal helps predict regionally specific responses of species to changing conditions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.