The Seagrass History of Florida Bay Reconstructed from Integrating Micropaleontological and Geochemical Proxies

综合微古生物学和地球化学指标重建的佛罗里达州海湾海草历史Laurel S.Collins，Rudolf Jaffe，James W.Fourqurean，William T.Anderson佛罗里达国际大学海岸环境条件的变化有多少是自然发生的，有多少是由人类造成的？这个问题是通过海草丰度的历史记录来解决的，今天海草丰度与环境水质高度相关。这项研究的背景是佛罗里达州海湾，这是面临环境挑战的大沼泽地国家公园的一部分。主要目标是收集佛罗里达州海湾沉积物的岩心，并使用其中包含的海草丰度指标作为过去数百年环境水质的指标。之所以使用海草替代品，是因为海草本身并不保存在沉积物中。地球化学指标是有机质(有机碳、氮、分子生物标志物、稳定同位素-d13C、d15N、Dd)的量度，微古生物指标是海草指示物种(有孔虫、硅藻)的丰度。高盐度最近被认为与佛罗里达州海湾大量海草的死亡有关。还将使用几个指标来确定历史盐度和海草变化之间的相关性。这笔赠款用于试点项目，从佛罗里达州海湾提取沉积物岩心，进行沉积学分析，确定辐射年龄，并将代用品校准为现代海草丰度和盐度。调查人员随后将从岩心收集地球化学和微古生物数据，将数据整合到统计分析中，并解释结果。通过将研究人员教授的地质学、生物和化学课程的结果结合起来，并为三篇研究生论文提供基础，知识得到了提升。FIU是一所联邦承认的少数民族大学。

ABSTRACTThe Seagrass History of Florida Bay Reconstructed from Integrating Micropaleontological and Geochemical ProxiesLaurel S. Collins, Rudolf Jaffe, James W. Fourqurean, William T. AndersonFlorida International UniversityHow much of the variation in coastal environmental conditions is naturally occurring and how much has been caused by humans? This question is addressed with the historical record of seagrass abundance, which today is highly correlated with environmental water quality. The study is set in Florida Bay, part of the environmentally challenged Everglades National Park. The main objective is to collect cores of Florida Bay sediment and use proxies of seagrass abundance contained therein as indicators of the environmental water quality for the past few hundred years. Proxies are used because seagrass itself is not preserved in sediments. The geochemical proxies are measures of organic matter (organic carbon, nitrogen, molecular biomarkers, stable isotopes - d13C, d15N, dD) and micropaleontological proxies are abundances of seagrass indicator species (foraminifera, diatoms). Hypersalinity has recently been linked to large seagrass die-offs in Florida Bay. Several proxies will also be used to determine the correlation between historical salinity and seagrass changes. This grant funds the pilot project to extract sediment cores from Florida Bay, conduct sedimentologic analyses, determine radiometric ages, and calibrate the proxies to modern seagrass abundances and salinities. The investigators will subsequently collect geochemical and micropaleontological data from the cores, integrate the data in statistical analyses, and interpret the results. Knowledge is advanced by incorporating the results in geology, biology and chemistry classes taught by the investigators, and providing the basis for three graduate student theses. FIU is a federally recognized minority university.