Collaborative Research: The effects of marine heatwaves on reproduction, larval transport and recruitment in sea urchin metapopulations

厄尔尼诺Niño和海洋热浪等快速和极端的变暖事件对近岸海洋生态系统产生了生态和经济影响。这些影响包括生物量减少和商业渔业的崩溃。对许多物种来说，种群的繁荣和萧条是由繁殖和幼崽扩散的变化控制的，这些变化与温度升高和海洋环流有关。然而，控制成虫繁殖和幼虫存活的相互作用过程如何塑造种群波动仍不清楚。海洋热浪经常伴随着海洋环流的严重中断，这可能影响产生自由漂浮的浮游生物幼虫的物种的生存和分布。因此，物种可以直接受到温度对生物繁殖和生存的影响，并间接受到影响幼虫成功的海洋环流变化的影响。这个项目正在研究温度和海洋环流的共同作用是如何控制紫海胆（strongylocentrrotus purpuratus）的数量的。为了实现项目目标，该团队正在开发海洋学模型，以预测浮游生物幼虫的扩散，并结合成虫繁殖成功的对照实验。该项目正在推进对生态重要物种如何响应海洋温度和环流的理解，预测海洋温度和环流将在未来气候变化情景下发生变化。该项目更广泛的影响包括在STEM和教育推广方面培训学生和博士后。课程开发和实施是与现有的K-12外展项目合作进行的，重点是服务不足的社区和代表性不足的群体。目标是使下一代科学家能够使用综合方法来预测气候变化的生态后果。紫海胆具有丰富的生态和生物数据，是研究变暖和海洋环流对其补充和生存耦合影响的理想物种。该物种有一个已绘制的基因组，可以作为幼虫被洋流长距离运输，加利福尼亚的幼虫丰度随着热浪和厄尔尼诺Niño的波动表现出数量级的变化。为了量化影响幼虫供应时空变化的过程，研究人员将生物物理建模、实验和统计建模结合起来，对南加州湾（SCB）幼虫定居的长期高分辨率数据进行了研究。研究模块1是使用SCB的3d生物物理模型量化幼虫运输的时空模式。该模型正在测试海洋环流和温度的历史变化、幼虫生活史和幼虫行为特征之间的相互作用如何影响幼虫供应在空间和时间上的变化。研究模块2的重点是温度如何影响鸡蛋产量的时空变化。实验描述了生殖热性能曲线，并量化了这些曲线在种群和有机体历史中的变化。一种新的测定方法正在评估与性能曲线相关的基因表达的表观遗传调控。最后，模块3将整合模块1和模块2的机制模型，对模块1和模块2在近30年的SCB六个地点幼虫定居数据集中解释时空趋势的能力进行统计评估。这是首次将幼虫运输、繁殖表现和定居数据模型结合起来的研究之一，以经验检验物理和生物过程如何影响复杂海洋元种群的当地招募模式。该奖项反映了美国国家科学基金会的法定使命，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。

Rapid and extreme warming events such as El Niño and marine heatwaves have had ecological and economic impacts on nearshore marine ecosystems. These impacts include reductions in biomass and collapses in commercial fisheries. For many species, population booms and busts are controlled by shifts in reproduction and juvenile dispersal related to warmer temperatures and ocean circulation. However, how population fluctuations are shaped by interacting processes that control adult reproduction and larval survival remains unclear. Marine heatwaves often accompany major disruptions in ocean circulation, which can affect survival and the distribution of species that produce free-floating, planktonic larvae. As a result, species can be impacted directly by temperature effects on organismal reproduction and survival, and indirectly by shifts in ocean circulation that affect larval success. This project is examining how the joint effects of temperature and ocean circulation are controlling populations of purple sea urchins (Strongylocentrotus purpuratus). To address project objectives, the team is developing oceanographic models to predict dispersal of planktonic larvae in combination with controlled experiments on adult reproductive success. This project is advancing the understanding of how ecologically important species respond to ocean temperature and circulation, which are forecast to shift under future climate change scenarios. Broader impacts of the project include training of students and post-docs in STEM and educational outreach. Curriculum development and implementation is occurring in collaboration with existing K-12 outreach programs that focus on underserved communities and under-represented groups. The goal is to empower the next generation of scientists to use integrative approaches to predict ecological consequences of climate change. Purple sea urchins are an ideal species for studying the coupled impacts of warming and ocean circulation on recruitment and survival given a wealth of ecological and organismal data. The species has a mapped genome, can be transported large distances as larvae by ocean currents, and larval abundances in California exhibit orders of magnitude variation with heatwaves and El Niño fluctuations. To quantify the processes that shape spatial and temporal variability in larval supply, researchers are applying a novel combination of biophysical modeling, experiments and statistical modeling of long-term, high-resolution data on larval settlement across the Southern California Bight (SCB). Research module 1 is quantifying spatial and temporal patterns of larval transport using a 3D-biophysical model of the SCB. The model is testing how interactions among historical changes in ocean circulation and temperature, larval life history, and larval behavioral traits affect variation in larval supply in space and time. Research module 2 is focused on how temperature could affect spatial and temporal variation in egg production. Experiments are characterizing reproductive thermal performance curves and quantifying how these vary among populations and organismal history. A novel assay is assessing epigenetic regulation of gene expression associated with performance curves. Finally, Module 3 will integrate mechanistic models from Modules 1 and 2 to statistically assess their ability to explain spatial and temporal trends in a nearly three-decade dataset of larval settlement from six sites in the SCB. This is one of the first studies that integrates models of larval transport, reproductive performance and settlement data to empirically test how physical and biological processes affect local recruitment patterns in complex marine meta-populations.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.