High-resolution sensing of nitrate in Monterey Bay and surrounding waters

蒙特利湾及周边水域硝酸盐的高分辨率传感

• 批准号: 1723278
• 负责人: Thomas Connolly
• 金额: $ 14.03万
• 依托单位: San Jose State University Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1723278&HistoricalAwards=false
• 关键词: resolution; sensing; nitrate; Monterey; Bay

Nitrate is an important nutrient in the ocean that sustains the use of energy from sunlight by photosynthetic organisms. Along the U.S. west coast, strong winds bring water that is rich in nitrate from the deep ocean to the sunlit ocean surface. This coastal upwelling process fuels growth and productivity at the base of the marine food web, but is also linked to low-oxygen conditions and harmful algal blooms along the coast. In addition to wind-driven upwelling along the coast, runoff of nitrate from land can cause excess enrichment of organic matter in estuaries, leading to low-oxygen conditions and habitat degradation. Traditional measurements of nitrate use chemical methods that are time consuming and limit the quantity of samples to those that can be physically collected in bottles. Recent advances in optical sensor technology have made it possible to collect nitrate data rapidly (up to one sample per second), allowing the collection of data with much greater detail. The purpose of this project is to make high-resolution sensing of nitrate a standard measurement at Moss Landing Marine Laboratories (MLML, https://www.mlml.calstate.edu) in central Monterey Bay, CA. Measuring nitrate alongside other observations of ocean conditions and water quality will provide a more complete picture of how nutrient availability changes over the course of days and months, and at small spatial scales down to meters in Monterey Bay and nearby estuaries. The use of high-resolution nitrate sensing at MLML will bring advanced technology into the classroom and provide new opportunities for student research. Training in the use and calibration of modern nitrate sensing technology will take place in the classroom, and students will have access to equipment and data for independent research. The nitrate sensors will support research on harmful algal blooms, regional impacts of ocean acidification, sustainable aquaculture, and estuarine water quality.Nitrate concentrations are influenced by many physical, biogeochemical and anthropogenic processes, including coastal upwelling, internal waves, photosynthesis, aerobic respiration, denitrification, and agricultural runoff. Nitrate fuels primary productivity, which is often also associated with low oxygen, eutrophication and harmful algae. However, the complex spatial distributions of nitrate, and the wide range of time scales of variability, are difficult to characterize with traditional methods. Recent advances in sensor technology have made it possible to measure variability in nitrate concentrations at the short temporal and spatial scales that characterize estuaries and coastal upwelling regions. The goal of this project is to make high-resolution sensing of nitrate a standard measurement on four observing platforms at Moss Landing Marine Laboratories (MLML, https://www.mlml.calstate.edu): 1) a seawater intake system that continuously measures subsurface water properties, 2) a vertically profiling rosette on a 56 ft. coastal research vessel, 3) an underway data acquisition system that continuously measures surface water properties on the same vessel, and 4) a portable underway data acquisition system that can be readily deployed on any small boat or pier. These research platforms already support an array of physical, biological and chemical sensors for interdisciplinary research in Monterey Bay and surrounding waters. Installing nitrate sensors on four complementary observing platforms would provide researchers in the Monterey Bay region with a strong foundation for understanding how nitrate and phytoplankton biomass vary both in time and space.

硝酸盐是海洋中的重要营养物质，维持光合生物对阳光能量的利用。沿着美国西海岸，强风将富含硝酸盐的水从深海带到阳光照射的海洋表面。这种沿海上升流过程促进了海洋食物网基础的生长和生产力，但也与沿海的低氧条件和有害藻华有关。除了沿海风驱动的上升流外，陆地上的硝酸盐径流还会导致河口有机物过度富集，导致低氧条件和栖息地退化。传统的硝酸盐测量使用化学方法，该方法非常耗时，并且将样品数量限制为可以物理收集在瓶子中的样品数量。光学传感器技术的最新进展使得快速收集硝酸盐数据成为可能（每秒最多一个样本），从而可以收集更详细的数据。该项目的目的是使硝酸盐的高分辨率传感成为加利福尼亚州蒙特利湾中部 Moss Landing 海洋实验室（MLML，https://www.mlml.calstate.edu）的标准测量。测量硝酸盐以及对海洋状况和水质的其他观测，将更全面地了解营养物可用性在数天和数月的过程中如何变化，以及在蒙特利湾和附近河口小至米的小空间尺度上的变化。 MLML 高分辨率硝酸盐传感技术的使用将把先进技术带入课堂，并为学生研究提供新的机会。现代硝酸盐传感技术的使用和校准培训将在课堂上进行，学生将可以使用设备和数据进行独立研究。硝酸盐传感器将支持有害藻华、海洋酸化的区域影响、可持续水产养殖和河口水质的研究。硝酸盐浓度受到许多物理、生物地球化学和人为过程的影响，包括沿海上升流、内波、光合作用、有氧呼吸、反硝化和农业径流。硝酸盐为初级生产力提供燃料，而初级生产力通常也与低氧、富营养化和有害藻类有关。然而，硝酸盐复杂的空间分布以及广泛的时间尺度变化很难用传统方法来表征。传感器技术的最新进展使得测量短时空尺度上硝酸盐浓度的变化成为可能，这些变化是河口和沿海上升流区域的特征。该项目的目标是使硝酸盐的高分辨率传感成为莫斯登陆海洋实验室（MLML，https://www.mlml.calstate.edu）四个观测平台的标准测量：1）连续测量地下水特性的海水摄入系统，2）56英尺沿海研究船上的垂直剖面玫瑰花结， 3) 一个在同一艘船上连续测量地表水特性的航行数据采集系统，以及 4) 一个可以轻松部署在任何小船或码头上的便携式航行数据采集系统。这些研究平台已经支持一系列物理、生物和化学传感器，用于蒙特利湾及周边水域的跨学科研究。在四个互补的观测平台上安装硝酸盐传感器将为蒙特利湾地区的研究人员了解硝酸盐和浮游植物生物量如何随时间和空间变化提供坚实的基础。