Collaborative Research: Field test of larval behavior on transport and connectivity in an upwelling regime

背景：大多数沿海海洋物种的幼虫是浮游的，通常游泳能力较弱。因此，它们被认为被海岸洋流广泛分散。然而，越来越多的证据表明，它们的行为会强烈地影响它们的运输：一些留在河口，而另一些则在成虫和幼虫的栖息地之间进行真正的迁徙，甚至到大陆架边缘和回来。幼虫的运输速度和方向被认为主要由垂直迁移的时间、持续时间和幅度以及幼虫在分层流中占据的平均深度决定。PI建议提供使用仿生漂流者的行为如何影响跨陆架和近岸运输的首批直接测试之一。这项研究将在持续上升流的地区进行，人们普遍认为那里的强流会淹没幼虫的游泳，并限制成年种群的招募。智力优势：有关调节幼虫运输的基本机制的知识，对于了解海洋生态和进化以及预测气候变化对海洋种群和群落的影响至关重要。该项目将提供第一个试验性的现场测试，测试幼虫的行为如何影响上升流状态下的运输和种群连接的速度、方向和距离。PIS将检验三个假设：1.在风力驱动的表层以下的栖息和该层以下的垂直迁徙使幼虫比在表层的栖息或没有深度偏好和垂直迁徙的幼虫更接近海岸。2.深部居留增强了近岸向北的输送，垂直迁移导致近岸平均位移量减小，但群体方差增大。深度偏好和垂直迁移对浮游生物在上升流区域的滞留和迁移有显著的影响。这项研究将比较来自模拟漂移者的直接测量结果与观察和模拟的跨陆架幼虫分布，以及与模拟的沿岸迁移。结果将广泛适用于大陆西部边缘的上升流系统，该方法也可以应用于世界各地的非上升流系统。广泛的影响：拟议的研究将支持两个机构的一名研究生和六名本科生。它还将为不同背景的大学生和高中生以及公众提供志愿者研究机会。这项研究将被纳入私人投资机构教授的大学课程，并将被添加到私人投资机构两个机构的网站和访客展示中。结果将通过私人投资机构的咨询协会传播给管理和设计海洋保护区网络的科学小组。

Background: The majority of larvae of coastal marine species are planktonic and generally weak swimmers. Thus, they are thought to be dispersed widely by coastal currents. However, there is accumulating evidence that their behavior can strongly influence their transport: some remain within estuaries, while others make true migrations between adult and larval habitats, even out to the edge of the continental shelf and back. Rates and directions of larval transport are thought to be determined largely by the timing, duration, and amplitude of vertical migrations and the mean depth that larvae occupy in stratified flows. The PIs propose to provide one of the first direct tests of how behavior affects across-shelf and alongshore transport using biomimetic drifters. The study will be conducted in a region of persistent upwelling, where strong currents are widely believed to overwhelm larval swimming and limit recruitment to adult populations. Intellectual merit: Knowledge of underlying mechanisms regulating larval transport is central to understanding ecology and evolution in the sea and anticipating the impacts of climate change on marine populations and communities. The project will provide the first experimental field-test of how larval behavior affects the rates, directions and distances of transport and population connectivity in an upwelling regime. The PIs will test three hypotheses: 1. Residence below the wind-driven surface layer and vertical migrations below that layer keep larvae closer to shore compared to residence in the surface layer or larvae without depth preferences and vertical migration. 2. Residence at depth enhances northward transport near shore, and vertical migration leads to decreased alongshore mean displacement but increased variance for a group.3. Depth preferences and vertical migrations have pronounced effects on retention and transport of plankton in upwelling regions.The study will compare direct measurements from mimetic drifters with observed and modeled cross-shelf larval distributions, and with modeled alongshore transport. Results will be broadly applicable to upwelling regimes along the western margins of continents, and the approach can be applied to non-upwelling systems throughout the world.Broader impacts: The proposed research will support a graduate student and six undergraduates at two institutions. It will also provide volunteer research opportunities for college and high school students with diverse backgrounds and for members of the public. The research will be included in college courses taught by the PIs, and will be added to websites and visitor displays at the PIs' two institutions. Results will be disseminated to science teams managing and designing Marine Protected Area networks through the PIs' advisory associations.