RUI: Analyzing demographic variability of the intertidal sea urchin Strongylocentrotus purpuratus in the context of oceanographic changes using a unique time series data set

许多海洋物种，从浮游生物到海鸟，都对海洋中不断变化的物理条件做出了反应。一些反应可能是由于个人的再分配，但其他反应似乎是由于生产力的变化和随后的二级生产。潮间带物种应该显示出对变化的海洋学条件的人口反应，但这一预测尚未得到检验，主要是因为普遍缺乏大多数潮间带物种的长期数据集。该项目使用了从加拿大温哥华岛到墨西哥蓬塔巴哈的紫色海胆（Strongylocentrotus purpuratus）的历史人口统计数据。一些数据来自于20世纪60年代和80年代的研究工作，一些数据来自于文献和同事的贡献。本研究的重点是建立和扩展这一独特的人口数据时间序列，并在海洋学变化的背景下进行分析。研究人员将重新考察沿岸的一些地点（和特定的潮池），在20世纪80年代和更早的时候，海胆在那里被取样，以检验潮间带物种对海洋条件的大规模变化做出反应的假设。当地的变化可能掩盖或淹没任何海洋学驱动的变化，而特定的潮池特征可能决定特定地点的过程。重点是评估大尺度海洋学过程对人口统计学五个方面的影响：生长、繁殖、补充、密度和生存。在估计招聘时，稳健的增长估计是区分0岁和老年人的关键。此外，生长与大小结构的结合是估计生存和二次生产的基础。将解决四个具体的增长问题：1)增长率是否会对不断变化的海洋条件做出反应？为了评估海洋学对生长的影响，需要考虑到海胆标记时间和一年后随后收集之间的条件变化所导致的生长变异性。此外，颚大小相对于体径的生长异速随食物的变化而变化。这一变化将在本研究期间进行评估。因此，第二个问题是：2)生长的逐年变化是否会影响用于量化生长的方法，生长异速是否与海洋指标相关？先前的工作证明了当地物理条件的潜在重要性，因此第三个生长问题是：3)潮汐池的暴露或其内部位置是否影响生长，异速生长差异是否反映了池内微站点资源的可变性？这些问题中对增长数据的解释依赖于模型，因此：4)哪种增长模型最合适？为了评估生殖的变化，每月将在八个地点测量性腺大小。在一些地点，可以获得20世纪50年代和60年代以及80年代的历史数据。我们将根据20世纪60年代至80年代取样人口的规模结构和90年代为数不多的可用地点来评估招聘的变化。体型分布形状的变化，特别是年龄为0岁的人口比例的变化，解决了一个问题：从加拿大到墨西哥沿海的最大招聘中心如何随着海洋条件的变化而变化？有1950年代、1960年代和1980年代的密度估计，因此有可能评估特定尺寸的密度是否发生了变化，以及任何变化是否与物理海洋学变化或其他环境变化（如海獭种群的变化）有关？过去二十年存活率的变化将被量化。与温度、疾病或捕食有关的可识别的地理模式将被探索。更广泛的影响&教育：该项目将增加学生参与研究的机会，主要是本科院校（维拉诺瓦）。学生将参与项目的各个方面：实地和实验室工作，数据分析，出版物的作者身份，以及在会议上的演讲。维拉诺瓦大学提供了一门本科课程，野外生态学和进化，包括一个扩展的基于野外的组成部分。本课程将于2008年开课，以北美太平洋潮间带生物群系为重点，并重点介绍本研究的野外地点。此外，该项目产生的信息将通过加州科学院的“科学现在”项目与更广泛的受众分享。

Many marine species, from plankton to sea birds, show a response to changing physical conditions in the ocean. Some responses may be due to redistribution of individuals but others appear to be due to changes in productivity and the subsequent cascade to secondary production. Intertidal species should show demographic responses to changing oceanographic conditions but this prediction has not been tested, primarily because of a general lack of long-term data sets for most intertidal species. This project uses historical demographic data for the purple sea urchin, Strongylocentrotus purpuratus, from Vancouver Island, Canada, to Punta Baja, Mexico. Some data are from previous work of the investigators in the 1960s and 1980s and some were compiled from the literature and contributions from colleagues. The focus of this study is to build on and extend this unique time-series of demographic data and analyze it in the context of oceanographic changes. The researchers will revisit sites (and specific tidepools) along the coast where sea urchins were sampled in the 1980s and earlier to test the hypothesis that intertidal species respond to large-scale changes in ocean conditions. Local variability could obscure or swamp any oceanographically-driven changes, and particular tidepools characteristics could determine site-specific processes. The focus is to assess the effects of large-scale oceanographic processes on five aspects of demography: growth, reproduction, recruitment, density, and survival. Robust growth estimates are central to separate age-0 from older individuals in estimating recruitment. In addition, growth combined with size structure is the basis of estimating survival and secondary production. Four specific growth questions will be addressed: 1) Do growth rates respond to changing ocean conditions? To assess oceanographic effects on growth requires accounting for growth variability due to changes in conditions between the time of marking urchins and subsequent collection after one year. In addition, growth allometry of jaw size relative to body diameter changes in response to available food. This change will be assessed for the present study period. Accordingly, the second question is: 2) Does year-to-year variation in growth affect methods used to quantify growth and can growth allometry be correlated with oceanographic metrics? Previous work demonstrates the potential significance of local physical conditions so the third growth question is: 3) Does exposure of a tidepool or position within it affect growth and do allometric differences reflect microsite resource variability within a pool? Interpretation of the growth data in these questions is model dependent, so: 4) Which growth model is most appropriate? To assess changes in reproduction, monthly gonad sizes will be measured at eight sites. At some sites, historical data from the 1950s and 1960s as well as the 1980s are available. We will assess changes in recruitment based on size structure of populations sampled from the 1960s through '80s and for the few available sites in the 1990s. Shifts in shapes of size distributions and in particular the fraction of the population represented by age-class-0 address the question: How does the center of maximum recruitment along the coast from Canada to Mexico shift in response to changing ocean conditions? There exist density estimates from the 1950s, 1960s and 1980s and so it will possible to assess whether size-specific density has changed and whether any changes are associated with physical-oceanographic changes or other environmental changes (such as changes in sea otter populations)? Changes in survival rates over the past two decades will be quantified. Recognizable geographic patterns that can be associated with temperature, disease, or predation will be explored. Broader Impacts & Education: This project will enhance opportunities for student participation in research at a primarily undergraduate institution (Villanova). Students will be involved in all aspects of the project: field and lab work, data analysis, authorship on publications, and presentations at conferences. Villanova offers an undergraduate course, Field Ecology and Evolution, that includes an extended field-based component. This course will be offered in 2008 and concentrate on the Pacific intertidal biome of North America and highlight field sites in this study. In addition, the information produced from this project will be shared with a wider audience through the Science NOW program at the California Academy of Science.