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Harmful Algal Blooms of the West Florida Shelf and Campeche Bank: Visualization and Quantification using Remote Sensing Methods.

机译：西佛罗里达州架子和坎佩切州银行的有害藻华：使用遥感方法进行可视化和量化。

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摘要

Harmful Algal Blooms (HABs) in the Gulf of Mexico (GOM) are natural phenomena that can have negative impacts on marine ecosystems on which human health and the economy of some Gulf States depends. Many of the HABs in the GOM are dominated by the toxic dinoflagellate Karenia brevis. Non-toxic phytoplankton taxa such as Scrippsiella sp. also form intense blooms off the Mexican coast that result in massive fish mortality and economic losses, particularly as they may lead to anoxia.;The main objectives of this dissertation were to (1) evaluate and improve the techniques developed for detection of Karenia spp. blooms on the West Florida Shelf (WFS) using satellite remote sensing methods, (2) test the use of these methods for waters in the GOM, and (3) use the output of these techniques to better understand the dynamics and evolution of Karenia spp. blooms in the WFS and off Mexico.;The first chapter of this dissertation examines the performance of several Karenia HABs detection techniques using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images and historical ground truth observations collected on the WFS from August 2002 to December 2011. A total of 2323 in situ samples collected by the Florida Fish and Wildlife Research Institute to test for Karenia spp. matched pixels with valid ocean color satellite observations over this period. This dataset was used to systematically optimize variables and coefficients used in five published HAB detection methods. Each technique was tested using a set of metrics that included the F-Measure (FM). Before optimization, the average FM for all techniques was 0.47. After optimization, the average FM increased to 0.59, and false positives decreased ~50%. The addition of a Fluorescence Line Height (FLH) criterion improved the performance of every method. A new practical method was developed using a combination of FLH and Remote Sensing Reflectance at 555 nm (Rrs555-FLH). The new method resulted in an FM of 0.62 and 3% false negatives, similar to those from more complex techniques. The first chapter concludes with a series of recommendations on how to improve the detection techniques and how to take these results a step further into a Gulf wide observing systems for HABs.;In chapter two, ocean color techniques were used to examine the extension, evolution and displacement of four Karenia spp. events that occurred in the WFS between 2004 and 2011. Blooms were identified in the imagery using the new Rrs-FLH method and validated using in situ phytoplankton cell counts. The spatial extension of each event was followed in time by delineating the blooms. In 2004 and 2005, the WFS was affected by a series of hurricanes that led to high river discharge and intense sediment resuspension events. Both processes had an impact on HAB occurrence. For example, I tracked a Karenia spp. bloom found in late December 2004 approximately 40-80 km offshore Saint Petersburg, which then expanded reaching an extension of >8000 km2 in February 2005. The bloom weakened in spring 2005 and intensified again in summer reaching >42,000 km 2 after the passage of hurricane Katrina in August 2005. This bloom covered the WFS from Charlotte Harbor to the Florida Panhandle. Two other cases were studied in the WFS. The results of the Hybrid Coordinate Ocean Model from the U.S. Navy aid understanding the dispersal of the blooms.;During fall 2011, three field campaigns to study HABs in Mexico were conducted to do an analysis of optical properties and explore the possibility of using ocean color techniques to distinguish between the main phytoplankton blooms in that region. Three main bloom scenarios were observed in the Campeche Bank region: massive diatom blooms, blooms dominated by Scrippsiella spp., and Karenia spp. blooms. The normalized specific phytoplankton absorption spectra were found to be different for Karenia spp. and Scrippsiella sp. blooms. A new technique that combines phytoplankton absorption derived from MODIS data and the new technique developed in Chapter One showed potential for a detection technique that can distinguish between Karenia and Scrippsiella blooms.;Additional work is needed to improve the new technique developed for Mexican waters, but results show potential for detection techniques that can be used Gulf-wide. This will help better understand the dynamic and possible connectivity of phytoplankton blooms in the GOM.
机译：墨西哥湾（GOM）中的有害藻华（HAB）是自然现象，会对某些海湾国家的人类健康和经济所依赖的海洋生态系统产生负面影响。 GOM中的许多HAB主要由有毒的鞭毛鞭毛小孢粉（Karenia brevis）主导。无毒浮游生物类群，如Scrippsiella sp.。墨西哥沿海地区也形成强烈的水华，导致大量鱼类死亡和经济损失，特别是可能导致缺氧。本论文的主要目的是（1）评估和改进开发用于检测卡伦氏菌的技术。使用卫星遥感方法在西佛罗里达大陆架（WFS）上开花，（2）测试这些方法在GOM中的水域中的使用，以及（3）使用这些技术的输出以更好地了解卡列尼亚菌的动态和演化。论文的第一章使用2002年8月至2011年12月在WFS上收集的中等分辨率成像分光辐射计（MODIS）卫星图像和历史地面真相观测数据，检验了几种Karenia HABs检测技术的性能。佛罗里达鱼类和野生动物研究所收集了总共2323个原位样品，用于测试克雷尼亚菌。在此期间将像素与有效的海洋颜色卫星观测值进行匹配。该数据集用于系统地优化五种已发布的HAB检测方法中使用的变量和系数。每种技术均使用包括F量度（FM）在内的一组度量进行了测试。在优化之前，所有技术的平均FM为0.47。优化后，平均FM增加到0.59，假阳性减少约50％。荧光线高度（FLH）准则的添加改善了每种方法的性能。通过结合使用FLH和555 nm的遥感反射率（Rrs555-FLH），开发了一种新的实用方法。与更复杂技术的结果类似，新方法产生的FM为0.62，假阴性率为3％。第一章以一系列建议作为结尾，就如何改进检测技术以及如何将这些结果进一步应用到海湾范围的HABs观测系统中提出了建议。第二章，使用了海洋颜色技术来检查扩展，演变过程和四个克雷尼亚属的位移。事件发生在2004年至2011年之间的WFS中。使用新的Rrs-FLH方法在影像中识别了花朵，并使用了原位浮游植物细胞计数进行了验证。每个事件的空间扩展都随着时间的推移划定了花朵。在2004年和2005年，世界粮食首脑会议受到了一系列飓风的影响，导致了高流量的河流和沉重的泥沙再悬浮事件。这两个过程都对HAB的发生有影响。例如，我跟踪了一个Karenia spp。 2004年12月下旬在圣彼得堡离岸约40-80 km处发现水华，然后扩大，在2005年2月扩展到超过8000 km2。在飓风过后，水华在2005年春季减弱，并在夏季再次增强，达到> 42,000 km 2 2005年8月，卡特里娜飓风。这朵花覆盖了从夏洛特港到佛罗里达州潘汉德尔的世界粮食首脑会议。世界粮食首脑会议研究了另外两个案例。美国海军的“混合坐标海洋模型”的结果有助于理解水华的散布。2011年秋季，进行了三场针对墨西哥HAB的野外研究，以分析光学特性并探索使用海洋色彩的可能性区分该区域主要浮游植物开花的技术。在坎佩切河沿岸地区观察到三种主要的开花情况：大型硅藻开花，以镰孢属（Scripppsiella spp。）和克雷尼亚属（Karenia spp）为主的开花。绽放。发现归一化的特定浮游植物吸收光谱对于克雷尼亚氏菌是不同的。和链霉菌属。绽放。将从MODIS数据中获得的浮游植物吸收与第一章中开发的新技术相结合的一项新技术显示出一种有可能区分出卡伦尼亚藻和镰刀菌水华的检测技术的潜力。结果显示了可以在海湾地区使用的检测技术的潜力。这将有助于更好地了解GOM中浮游植物开花的动态和可能的连通性。

著录项

  • 作者

    Soto Ramos, Inia Mariel.;

  • 作者单位

    University of South Florida.;

  • 授予单位 University of South Florida.;
  • 学科 Biology Oceanography.;Remote Sensing.
  • 学位 Ph.D.
  • 年度 2013
  • 页码 134 p.
  • 总页数 134
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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