Biological Consequences of Environmental Change in the Bivalve, Astarte: Relationships Between Lifespan, Growth Rate, and Cold vs. Warm Climate States

环境变化的生物学后果是什么？本研究的目的是确定区域气候和地理范围大小对美国东南部沿海平原和北大西洋中部发现的现代和化石种群中常见蛤蜊物种的壳生长速度和寿命的影响。研究中包括的种群将有助于了解环境变化如何影响生活在不同年温度范围地区的双壳类动物的寿命。研究结果将提高我们对环境变化对生活在敏感沿海栖息地的生物的影响的认识。我们的方法和结果将具有显著的教育效益，特别是对于来自代表性不足的群体的学生（例如，对STEM领域感兴趣的第一代大学生），并将通过使用STEM教育机制刺激创新而被高中生和本科生使用。通过UNC-BEST（科学与教学学士学位教育）计划，我们将奖励未来的高中地球科学教师进行科学研究的机会，这些研究将为K-12科学课程提供真正的实验室课程。我们将帮助彭德县学校（服务于低收入和弱势家庭）的教师通过“科学写作和科学写作”项目（与联合国儿童基金会的合作项目）将写作与科学发现结合起来，改善教学。由于星螺壳的大小和生物地理分布随时间的变化，它们非常适合研究环境变化和生物后果之间的联系（例如，寿命和代谢率的变化）。我们将重点关注沿美国中大西洋和墨西哥湾沿岸平原的上新世-更新世沉积物中丰富的Astarte种群以及北大西洋的现代种群。主要目的是：1)利用同位素年代学方法建立现代和化石星蹄草不同生物地理种群年生长检查的季节时间；2)建立生物地理带与生长速率和寿命的关系；3)建立气候状态与生长速率和寿命的关系。目标2和3采用von Bertalanffy生长方程及其导数（标准生长指数；SGI）来比较现代和化石、跨生物地理区域以及寒冷和温暖气候之间种群的壳生长。我们的零假设将使用混合模型方差分析和主成分分析检验。这些试验将确定控制阿斯达尔种群间变异的主要成分。这项研究为生物地理分布和季节温度范围的差异如何影响双壳类的生长和寿命以及变化的条件如何影响未来的种群提供了更好的理解。

What are the biological consequences of environmental change? The goal of this research is to determine the impact of regional climate and geographic range size on the shell growth rate and lifespan of a common clam species from modern and fossil populations found along the southeastern US coastal plains and Mid-North Atlantic. The populations included in the study will provide an understanding of how environmental change will affect the lifespan of bivalves that live in regions with different annual temperature ranges. Outcomes will advance our knowledge of the effects of environmental change on organisms that live in sensitive coastal habitats. Our methods and results will have a significant educational benefit, especially for students from underrepresented groups (e.g., first-generation college students interested in STEM fields), and will be used by high school and undergraduate students by stimulating innovation using STEM educational mechanisms. Through the UNC-BEST (Baccalaureate Education in Science & Teaching) program, we will award future high-school earth science teachers the opportunity to perform scientific research that will generate authentic laboratory curricula for K-12 science courses. We will help teachers from Pender County Schools (which serves low income and disadvantaged households) to improve instruction by integrating writing with scientific discovery through the "Writing in Science and Science in Writing" program (a collaborative program with UNCW).Astarte shells are uniquely suited to investigate links between environmental change and biological consequences (e.g., changes in lifespan and metabolic rate) because of their change in size and biogeographic distribution through time. We will focus on the abundant populations of Astarte in Plio-Pleistocene deposits along the US Mid-Atlantic and Gulf Coastal Plains and modern populations in the North Atlantic. The main objectives are to: 1) establish the seasonal timing of annual growth checks in different biogeographic populations of modern and fossil Astarte using isotope sclerochronology; 2) establish the relationship between biogeographic zone to growth rate and lifespan; and 3) establish the relationship of climate state to growth rate and lifespan. Objectives 2 and 3 employ the von Bertalanffy growth equation and its derivative (standard growth index; SGI) to compare shell growth of a population between modern and fossil, across biogeographic zones, and between cold vs. warm climates. Our null hypotheses will be tested using a mixed model ANOVA and PCA tests. These tests will determine the principal components controlling variability among Astarte populations. This study provides a greater understanding of how biogeographic distribution and differences in seasonal temperature range may influence bivalve growth and longevity and how changing conditions may affect future populations.