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生物，一般游泳能力较弱。因此，它们被认为被沿海洋流广泛散布。然而，越来越多的证据表明，它们的行为可以强烈地影响它们的运输：一些留在河口内，而另一些则在成虫和幼虫栖息地之间进行真正的迁徙，甚至到达大陆架边缘再返回。据认为，幼虫迁移的速率和方向主要取决于垂直迁移的时间、持续时间和幅度以及幼虫在分层流中所处的平均深度。pi建议提供使用仿生漂浮物的行为如何影响跨大陆架和沿岸运输的第一个直接测试之一。这项研究将在一个持续上升流的地区进行，人们普遍认为，在那里，强大的水流会压倒幼虫的游泳能力，并限制成年种群的招募。知识价值：了解调节幼虫运输的潜在机制对于理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实验性的实地测试，以了解在上升流状态下，幼虫的行为如何影响迁徙的速度、方向和距离以及种群的连通性。pi将测试三个假设：1。与居住在表层或没有深度偏好和垂直迁移的幼虫相比，居住在风力驱动的表层以下和垂直迁移的幼虫更接近岸边。2. 深层居住增强了近岸向北迁移，垂直迁移导致岸线平均位移减小而方差增大。在上升流区，深度偏好和垂直迁移对浮游生物的滞留和迁移有显著影响。这项研究将把模拟漂流者的直接测量结果与观察到的和模拟的跨大陆架幼虫分布以及模拟的沿岸运输进行比较。结果将广泛适用于沿大陆西部边缘的上升流体系，并且该方法可以应用于世界各地的非上升流体系。更广泛的影响：拟议的研究将支持两所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和高中学生以及公众提供志愿研究机会。这些研究成果将被纳入pi教授的大学课程，并将被添加到pi所在的两所机构的网站和访客展示中。研究结果将通过海洋保护区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.