CAREER: Identifying primary and secondary drivers of cyanotoxin production utilizing the sediment record and paleolimnology

世界各地的湖泊正在经历藻类和蓝藻的过度生长。这些变化的原因尚不完全清楚。在许多湖泊中，蓝藻能够产生毒素（蓝藻毒素），这可能会对湖泊生物和人类健康产生负面影响。 虽然近年来监测计划和实验室实验有所增加，但人们对蓝藻毒素生态学和蓝藻毒素生产历史知之甚少。 该CAREER奖将分析从美国东南部和墨西哥的25个湖泊收集的沉积物岩心，并用于重建蓝藻毒素生产和其他湖泊重要的生态因素。 三个时间尺度将被调查，包括现代人类干扰（过去~100年），前现代干扰（500至5000年），和玛雅人占领期间的古代人类干扰在墨西哥湖泊周围。该奖项还将为从高中到研究生院的学生提供教育材料、指导和培训，重点是农村地区的学生。 该职业奖将测试有关湖泊生态系统状态变化的基本理论，以及通过使用古湖沼学来确定整个全新世湖泊生态系统中蓝藻毒素生产的基线条件和过去轨迹的称为闪烁的早期预警信号的潜力。将利用沉积物记录的人类、营养物、温度及其组合的历史干扰进行独特的实验，以确定蓝藻毒素产生的历史驱动因素。 在文化和自然生态系统变化过程中更好地了解蓝藻毒素生态学，将提高预测模型的能力，以预测未来的气候，土地利用变化和湖泊管理将如何影响蓝藻毒素生产，以及建立蓝藻毒素生产的古历史。 将蓝藻毒素确定为一种沉积工具，可以改善全球古湖泊学调查，重点是富营养化以及监测沉积物中的蓝藻毒素。最后，测量蓝藻毒素玛雅人占领的湖泊可以提供新的理解古代社会和水质之间的关系，作为一个模拟现代文化的富营养化。将实施一个层级指导系统，以培训高中生、本科生和研究生，将项目的各个方面纳入教育课程，包括到墨西哥湖泊进行海外学习，本科生沉积物分析实验室课程，以及通过课堂练习与高中生建立联系。 这项研究的结果将有助于理解、预测和影响与人类和湖泊富营养化有关的蓝藻毒素。该奖项反映了NSF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。

Lakes around the world are experiencing the excessive growth of algae and cyanobacteria. The causes for these changes are not fully known. In many lakes, the cyanobacteria are capable of producing toxins (cyanotoxins), which can negatively affect lake organisms and human health. While monitoring programs and laboratory experiments have increased in recent years, very little is known about the cyanotoxin ecology and the history of cyanotoxin production prior to human disturbances. This CAREER award will analyze sediment cores collected from over 25 lakes throughout the SE USA and Mexico and used to reconstruct cyanotoxin production and other lake important ecological factors through time. Three timescales will be investigated including modern human disturbance (past ~100 years), pre-modern disturbance (500 to 5000 years), and ancient human disturbance during Maya occupation around lakes in Mexico. This award will also provide educational materials, mentoring, and training to students from high school through graduate school with a focus on students from rural areas. This CAREER award will test fundamental theories about state changes in lake ecosystems and the potential for early warning signs termed flickering by using paleolimnology to establish baseline conditions and past trajectories of cyanotoxin production in lake ecosystems throughout the Holocene. Unique experiments will be conducted using sediment-recorded historic disturbances of humans, nutrients, temperature and combinations of each to determine historic drivers of cyanotoxin production. A better understanding of cyanotoxin ecology during cultural and natural ecosystem change will improve the ability of forecasting models to predict how future climate, land use change, and lake management will influence cyanotoxin production as well as establish paleo-histories of cyanotoxin production. The establishment of cyanotoxins as a sedimentary tool could improve global paleolimnological investigations focusing on eutrophication as well as the monitoring of sediments for cyanotoxins. Finally, the measurement of cyanotoxins on Maya-occupied lakes could provide new understanding to the relationship between ancient societies and water quality as an analog to modern cultural eutrophication. A tier-mentoring system will be implemented to train high school, undergraduate and graduate students that will integrate various aspects of the project into educational curriculum including a study abroad trip to lake sites in Mexico, an undergraduate lab course on sediment analysis, and connections with high school students through classroom exercises. Results from this research will aid in the understanding, prediction, and impact of cyanotoxins linked to humans and lake eutrophication.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.