Hydrogen isotope response of algal lipids to variable nutrient concentrations in Swiss lakes

GSTDTAP

项目编号	1452254
	Hydrogen isotope response of algal lipids to variable nutrient concentrations in Swiss lakes
	Sarah Ladd
主持机构	Ladd Sarah N
项目开始年	2015
	2015-04-01
项目结束日期	2017-03-31
资助机构	US-NSF
项目类别	Fellowship
项目经费	184000(USD)
国家	美国
语种	英语
英文摘要	Dr. S. Nemiah Ladd has been granted an NSF Earth Sciences postdoctoral fellowship to study how fossilized algal remains record nutrient pollution. This fellowship will allow an early career American scientist to carry out a research project at Eawag, the Swiss Federal Institute of Aquatic Science and Technology. Eutrophication (nutrient pollution of lakes and other aquatic ecosystems) is commonly caused by fertilizers and detergents. It can result in harmful algal blooms and widespread fish death, and reduces the economic and aesthetic value of water bodies. The Swiss government has been especially proactive about reducing the causes of eutrophication and remediating polluted lakes. However, despite concerted efforts over the past thirty-five years, a range of nutrient concentrations persists among lakes in the central Swiss plateau. This project will develop a novel tool to reconstruct past nutrient levels in lakes from molecular algal fossils in lake sediment. It will also refine the use of existing proxies of past climate, which are based on the same sedimentary markers. During her fellowship, Dr. Ladd will promote the education of young scientists from developing countries by collaborating with the Eawag Partnership Program (EPP) to create a mentoring program to support visiting graduate students. Because EPP fellows will take newly honed skills back to their local institutions, and use them to address local problems, support of the EPP fellowship program will more broadly impact the advancement of science in Africa and Asia, and facilitate the study of a range of environmental, economic, and social issues related to water use and quality throughout the developing world. Lipids produced by algae are resistant to degradation and can persist unchanged in sediment for millions of years. They typically record the hydrogen isotope composition of the water in which the algae grew, which is controlled by climatic variables such as temperature, rainfall, and atmospheric circulation patterns. Algal lipids have therefore been developed as a useful proxy for past climate. However, several other variables can influence the isotopic composition of algal lipids. Of particular importance for this project, in laboratory studies hydrogen isotope fractionation in marine algae is highly sensitive to nutrient availability. By measuring isotope fractionation in algal lipids from living algae, falling particles, and surface sediment in Swiss lakes with variable phosphate concentrations, this project will for the first time establish whether nutrient availability and growth rate affect hydrogen isotope fractionation in natural settings, and for freshwater algae. In the second phase of this work, the environmental histories of different lakes will be reconstructed by applying the results of the calibration study to sediment cores. Determining the natural variability among lakes with identical climate histories will permit a more complete assessment of ongoing pollution remediation strategies. This award was supported with funding from the Office of International and Integrative Activities.
来源学科分类	Geosciences - Earth Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/67764
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Sarah Ladd.Hydrogen isotope response of algal lipids to variable nutrient concentrations in Swiss lakes.2015.