Dissertation Research:Shifting Baselines? The ecological implications of simultaneous eutrophications and overfishing

论文研究：改变基线？

基本信息

批准号：
1010931
负责人：
Amy Rosemond
金额：
$ 1.45万
依托单位：
University of Georgia Research Foundation Inc
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2010
资助国家：
美国
起止时间：
2010-08-01 至 2012-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1010931&HistoricalAwards=false
关键词：
Dissertation Research Shifting Baselines ecological

项目摘要

Shifting Baselines? The ecological implications of simultaneous eutrophication and overfishingOverfishing and human-derived nutrient pollution are among the most pressing issues facing coastal environments globally. Both these stressors affect the supply of growth-limiting nutrients (nitrogen (N) and phosphorus (P)) for algae and seagrasses, the base of most marine ecosystems. Human inputs increase the supply of nutrients, which are largely sewage-derived, while overfishing has been shown to reduce nutrient supply because fish provide substantial inputs of nutrients via excretion. These contrasting inputs present the paradox that human-derived nutrients may supplant fish-derived nutrients. However, human-derived nutrients are high in P relative to fish-derived nutrients, which may be altering the baseline at which nutrients are supplied and in turn changing the diversity and growth rates of algae and seagrass species. Overfishing and nutrient enrichment will be simulated independently and simultaneously on experimental patch-reef ecosystems in the Bahamas. The implications for changes in diversity, growth and nutrient limitation of algae and seagrass species will be determined . The experimental reef system will be used as a field trip site and experimental results will be used in outreach efforts to local high school students. Subtropical and tropical marine ecosystems have evolved to function under extremely low nutrient conditions, making them particularly susceptible to even minor alterations in nutrient dynamics. The enormous services provided by these ecosystems appear to critically hinge on the amount and relative supply of N and P, yet understanding of the effects of simultaneous overfishing and eutrophication for these services is lacking, particularly in the Caribbean. Increased understanding of nutrient effects is critical to the management and conservation of marine ecosystems globally.

改变基线？富营养化和过度捕捞同时发生的生态影响过度捕捞和人为营养物污染是全球沿海环境面临的最紧迫问题之一。这两种压力因素都会影响藻类和海草（大多数海洋生态系统的基础）生长限制营养物质（氮 (N) 和磷 (P)）的供应。人类的投入增加了营养物的供应，而营养物主要来自污水，而过度捕捞已被证明会减少营养物的供应，因为鱼类通过排泄提供大量的营养物输入。这些对比鲜明的输入呈现出一个悖论：人类来源的营养物质可能会取代鱼类来源的营养物质。然而，相对于鱼类来源的营养物质，人类来源的营养物质的磷含量较高，这可能会改变营养物质供应的基线，进而改变藻类和海草物种的多样性和生长速度。过度捕捞和营养富集将在巴哈马的实验性斑礁生态系统中同时独立模拟。将确定藻类和海草物种多样性、生长和营养限制变化的影响。实验珊瑚礁系统将用作实地考察地点，实验结果将用于向当地高中生进行推广活动。亚热带和热带海洋生态系统已经进化到在极低的营养条件下发挥作用，这使得它们特别容易受到营养动态的微小变化的影响。这些生态系统提供的巨大服务似乎关键取决于氮和磷的数量和相对供应，但人们缺乏对过度捕捞和富营养化同时对这些服务的影响的了解，特别是在加勒比地区。加深对营养物质影响的了解对于全球海洋生态系统的管理和保护至关重要。