DISSERTATION RESEARCH: Stable Isotope Analysis of Current and Historical Aquatic Food Webs

论文研究：当前和历史水生食物网的稳定同位素分析

• 批准号: 0308825
• 负责人: Thomas Turner
• 金额: $ 0.8万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0308825&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Stable; Isotope; Analysis

Human alteration of river ecosystems is an enormous concern worldwide. This study is focused in the Middle Rio Grande (MRG) of New Mexico, which has been severely altered since the early 1900s. The overall aim of the research is to document present conditions and reconstruct past conditions of the MRG aquatic food web to understand how river regulation (e.g., dam and levee construction, large-scale diversion of water for human use) has affected organisms that live there. Naturally occurring stable isotopes will be used as biochemical tracers to document production and cycling of food energy through the entire MRG ecosystem from plants to fishes. We will then compare isotope signatures of present day fishes to historical fish specimens held in the Museum of Southwestern Biology (up to 63 years) to evaluate (i) changes over time in carbon sources entering the food web due to altered flood cycles, (ii) changes in fish food web as non-native fish species increased in abundance and many native fishes declined, and (iii) variation in nitrogen fertilizer inputs from agriculture over time. This research will advance knowledge of how aquatic communities respond to river regulation over decadal time spans. More broadly, this research focuses on developing a novel method to address the challenging problem of reconstructing community food web structure and function following river ecosystem alteration.

人类对河流生态系统的改变是世界范围内的一个巨大问题。 这项研究的重点是新墨西哥州的中里奥格兰德 (MRG)，该地区自 1900 年代初以来已经发生了严重的变化。 该研究的总体目标是记录 MRG 水生食物网的现状并重建过去的状况，以了解河流调节（例如水坝和堤坝建设、大规模引水供人类使用）如何影响生活在那里的生物。 天然存在的稳定同位素将用作生化示踪剂，记录从植物到鱼类的整个 MRG 生态系统中食物能量的生产和循环。 然后，我们将把当今鱼类的同位素特征与西南生物博物馆保存的历史鱼类标本（长达 63 年）进行比较，以评估 (i) 由于洪水周期改变而进入食物网的碳源随时间的变化，(ii) ）随着非本地鱼类数量的增加和许多本地鱼类的减少，鱼类食物网发生变化，以及（iii）农业氮肥投入随时间的变化。 这项研究将增进人们对水生生物群落在十年时间跨度内如何应对河流调节的了解。 更广泛地说，这项研究的重点是开发一种新方法来解决河流生态系统改变后重建社区食物网结构和功能的挑战性问题。