Collaborative Research: RAPID: Assessing the Ecophysiological and Biogeochemical Response to Deliberate Nutrient Loading in the Southern California Bight

合作研究：RAPID：评估南加州湾对蓄意营养物负荷的生态生理和生物地球化学反应

• 批准号: 1251547
• 负责人: Andrew Lucas
• 金额: $ 7.49万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1251547&HistoricalAwards=false
• 关键词: Collaborative; Research; RAPID; Assessing; Ecophysiological

In autumn 2012, Orange County Sanitation District (OCSD) will divert ~150 million gallons/day of secondarily-treated effluent to a nearshore (1 mile offshore) outfall pipe over a period of ~4 weeks. No discharges of this magnitude have been conducted in decades. The planned diversion is expected to create a buoyant surface plume that will spread over much of the coastal region. Because OCSD plans to "super-chlorinate" and then dechlorinate the discharge, the effect of the plume should be predominantly a nutrient addition rather than direct addition of intact microbial populations. The PIs propose to address two broad questions through a study of the plume. First, what happens ecologically and physiologically to the phytoplankton assemblage when nutrients are discharged in the surface ocean for extended periods of time? Second, can this dynamic and shifting environment be sampled by deploying multiple technologies to identify the physical/chemical drivers of the biological response at ecologically relevant space and time scales? They will test two hypotheses: H1: Continual discharge of nutrients to the surface ocean results in a dinoflagellate-dominated bloom which leads to dampening or cessation of vertical migration of the dinoflagellates and drives a shift to net heterotrophy. H2: The bloom will initially result in a strong local sink for carbon dioxide which gradually develops into a strong source as heterotrophy develops.The study is expected to provide a time-evolving picture of interactions within and between autotrophic and heterotrophic communities and will illustrate the short-term biogeochemical and ecological consequences of sustained nutrient discharge to a shallow coastal site. The planned diversion provides an unprecedented opportunity to study the ecophysiological response in a natural setting over a period of weeks, including the interaction of biology, chemistry, and physics, and it will contribute to basic understanding of anthropogenic nutrient loading to the coastal ocean. Undergraduate and graduate education and training will be furthered through active participation in lab, field, and data synthesis activities involving academic, government, and industry partners.

2012年秋季，橙子县卫生区（OCSD）将在约4周的时间内将约1.5亿加仑/天的二级处理污水转移到近岸（离岸1英里）排放管。几十年来从未进行过如此规模的排放。计划中的转移预计将产生一个漂浮的表面羽流，将蔓延到大部分沿海地区。由于OCSD计划对排放物进行“超级氯化”，然后再进行脱氯，因此羽流的影响主要是增加营养物，而不是直接增加完整的微生物种群。PI建议通过对羽流的研究来解决两个广泛的问题。 首先，当营养物质长时间排放到海洋表面时，浮游植物群落在生态和生理上会发生什么？第二，能否通过部署多种技术对这种动态和不断变化的环境进行采样，以确定在生态相关的空间和时间尺度上生物反应的物理/化学驱动因素？他们将测试两个假设：H1：持续排放的营养物质的表面海洋的结果在甲藻为主的水华，导致抑制或停止的甲藻的垂直迁移，并驱动器的净异养的转变。H2：水华最初会导致一个强大的本地二氧化碳汇逐渐发展成为一个强大的源异养developments.The研究预计将提供一个时间演变的图片内和之间的相互作用的自养和异养communities，并将说明短期的生物地球化学和生态后果的持续营养排放到一个浅的沿海网站。计划中的转移提供了一个前所未有的机会，可以在自然环境中研究生态生理反应，包括生物学，化学和物理学的相互作用，并将有助于基本了解沿海海洋的人为营养负荷。本科和研究生教育和培训将通过积极参与实验室，现场和数据合成活动，涉及学术，政府和行业合作伙伴进一步。