A review of ocean color remote sensing methods and statistical techniques for the detection, mapping and analysis of phytoplankton blooms in coastal and open oceans

The need for more effective environmental monitoring of the open and coastal ocean has recently led to notable advances in satellite ocean color technology and algorithm research. Satellite ocean color sensors' data are widely used for the detection, mapping and monitoring of phytoplankton blooms because earth observation provides a synoptic view of the ocean, both spatially and temporally. Algal blooms are indicators of marine ecosystem health; thus, their monitoring is a key component of effective management of coastal and oceanic resources. Since the late 1970s, a wide variety of operational ocean color satellite sensors and algorithms have been developed. The comprehensive review presented in this article captures the details of the progress and discusses the advantages and limitations of the algorithms used with the multi-spectral ocean color sensors CZCS, SeaWiFS, MODIS and MERIS. Present challenges include overcoming the severe limitation of these algorithms in coastal waters and refining detection limits in various oceanic and coastal environments. To understand the spatio-temporal patterns of algal blooms and their triggering factors, it is essential to consider the possible effects of environmental parameters, such as water temperature, turbidity, solar radiation and bathymetry. Hence, this review will also discuss the use of statistical techniques and additional datasets derived from ecosystem models or other satellite sensors to characterize further the factors triggering or limiting the development of algal blooms in coastal and open ocean waters

光学特性が複雑な水域における超多波長反射率データを使った新しい水質推定手法の構築

広島大学(Hiroshima University)博士(工学)Doctor of Engineeringdoctora

SISTEM PERINGATAN DINI UNTUK MARAK ALGA MENGGUNAKAN CITRA SATELIT DI TELUK JAKARTA

Jakarta Bay is experiencing eutrophication, primarily due to nutrient inflows from agriculture, industry, and urban sources. This abundance of nutrients has led to significant algae blooms. A study using Terra and Aqua MODIS satellite data from 2004 to 2007 monitored these blooms by measuring chlorophyll-a levels. During this period, large-scale fish kills were observed directly related to the algal blooms, as evidenced by high chlorophyll-a concentrations and blooms covering more than a quarter of the bay. Interestingly, not all intense blooms resulted in massive fish kills. The study suggests that this mortality is primarily due to oxygen depletion after peak bloom periods, compounded by poor water circulation in the bay. Using satellite imagery to monitor algal blooms is a practical tool for implementing an early warning system (EWS) in Jakarta Bay. Satellite imagery has proven effective in monitoring these blooms and could help develop an early warning system in Jakarta Bay despite limitations such as cloud cover.Teluk Jakarta telah mengalami eutrofikasi, terutama disebabkan oleh masuknya nutrien dari sumber pertanian, industri, dan perkotaan. Kelimpahan nutrien ini telah menyebabkan terjadinya marak alga yang signifikan. Studi dengan menggunakan data satelit Terra dan Aqua MODIS dari tahun 2004 hingga 2007 telah memantau marak alga ini dengan mengukur tingkat klorofil-a. Selama periode ini, terjadi kematian massal ikan yang secara langsung terkait dengan peristiwa marak alga, seperti yang dibuktikan dengan tingginya konsentrasi klorofil-a dan marak alge yang menutupi lebih dari seperempat teluk. Menariknya, tidak semua marak alge yang intens mengakibatkan kematian ikan massal. Studi tersebut menunjukkan bahwa kematian ini terutama disebabkan oleh kekurangan oksigen setelah periode marak alge mencapai puncak, yang diperburuk oleh sirkulasi air yang lemah di teluk ini. Penggunaan citra satelit untuk memantau marak alga adalah alat yang praktis untuk menerapkan sistem peringatan dini (EWS) di Teluk Jakarta. Citra satelit telah terbukti efektif dalam memantau marak alga ini dan dapat membantu mengembangkan sistem peringatan dini di Teluk Jakarta meskipun terdapat keterbatasan seperti adanya penutupan awan

Earth Resources: A continuing bibliography with indexes, issue 16, January 1978

This bibliography lists 543 reports, articles, and other documents introduced onto the NASA scientific and technical information system between October 1 and December 31, 1977. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis

The use of operational harmful algal bloom monitoring systems in South Africa to assess long term changes to bloom occurrence & impacts for aquaculture

The south coast of South Africa is a very dynamic, productive, high energy environment and is considered to be a generally challenging setting for in-water aquaculture. One of the largest environmental threats to aquaculture are harmful algal blooms (HABs), a natural ecological phenomenon often accompanied by severe impacts on coastal resources and local economies. There is a wide variety of potentially harmful blooming species in the region, with impacts resulting from both toxicity and the negative effects associated with high biomass. While HABs are fairly well documented around the southern Benguela area, the primary concern is the lack of long-term data showing if blooms are becoming more frequent, persistent or are having greater impact over the last decades, consistent with environmental change experienced in the region. For this study, high-resolution satellite remote sensing observations from 16 years of MODIS-Aqua (1 km) and one month of Sentinel-3 OLCI (300 m), using regionally optimised blended algorithms, were used to investigate the spatial distribution and temporal variability of chlorophyll-a (Chl-a) along the south coast of South Africa. A Chl-a threshold of 27 mg m−3 was used as an analytic to identify the occurrence of high biomass blooms in the remote sensing data. Phytoplankton count data from aquaculture farms are used to provide information corresponding to changes in phytoplankton community structure, and to investigate the distribution and seasonal trends of HABs along the south coast. To further explore the spatial and temporal distribution, phytoplankton species considered harmful for this study were identified and classified to their seasonal occurrence: some species were consistently present throughout the years, however each region showed contrasting seasonality. A second interest of this study is linked to assessing the capacity of the aquaculture industry to make profitable use of existing observational and early warning tools. The impact of HABs on the environment or in aquaculture facilities can be potentially mitigated by increasing the industry awareness and early warnings of HAB development. In this regard, the Fisheries and Aquaculture Decision Support Tool (DeST) was used in order to develop short term alerts on HAB development. The EO analyses conducted here specifically use the same methods used by this DeST to demonstrate the use of this tool for historical analysis in addition to real time alerting. In order to evaluate the effectiveness of the tool and how the aquaculture farmers use the ABSTRACT information provided on the DeST, an online user feedback was generated, and distributed to all stakeholders via emai

Optical discrimination among dinoflagellate species causing Harmful Algal Blooms (HABs) in Korean coastal waters

이 연구는 한국 연안에서 발생하는 유해 적조(Harmful Algal blooms)를 광학적으로 구별하는 방법을 개발하기 위해 진행되었으며, 특히 주요 유해 적조 원인 종으로 알려진 와편모조류 Cochlodinium polykrikoides에 초점을 맞추어 생물 광학적 특성을 활용한 적조 탐지 가능성에 대한 연구를 하였다. 이 연구에서는 실험실에서 배양 중인 C. polykrikoides를 비롯한 다른 와편모조류 유해 적조 종들의 흡광 스펙트럼을 측정하여 적조 종이 가지는 고유한 흡광 특성을 파악하였다. 또한 유해 적조 종의 고유 광 특성 의한 반사도 스펙트럼의 분광 반응을 바탕으로 광학적 구별 방법을 제시하였다. 연구에 활용된 반사도 스펙트럼(N = 2,275)은 실험으로 측정한 적조 종 흡광 자료와 International Ocean-Color Coordinating Group에서 제공하는 자료를 사용하여 광학 모델인 Hydrolight를 통해 모의되었다. 해수의 반사도에 영향을 미치는 해수 구성요소의 농도를 다양하게 설정하여 폭넓은 광학적 조건을 포괄하는 2,275개의 반사도 스펙트럼을 생성하였다. 모의 된 반사도 스펙트럼 자료를 분석한 결과, C. polykrikoides를 포함한 4 종의 유해 적조 종의 반사도 스펙트럼 간에는 높은 유사도를 보인 반면, 적조가 아닌 경우의 반사도와 적조인 경우의 반사도는 뚜렷한 차이를 보였다. 특히, C. polykrikoides 적조인 경우에 청-녹 파장에서 보이는 고유한 흡광 특성이 반사도에 영향을 줌으로써 적조가 아닌 경우의 반사도와 구별되는 특징을 보였고 이 차이를 바탕으로 C. polykrikoides 구별 방법을 제시하였다. R1: Rrs(555)/Rrs(531)와 R2: Rrs(488)/Rrs(443), 두 반사도 밴드 비를 사용하여 적조가 아닌 경우로부터 효과적으로 C. polykrikoides blooms를 구별할 수 있었다. 모의 된 반사도 자료를 바탕으로 제안 된 두 반사도 밴드 비를 실제 한국 연안에서 측정한 반사도에 적용한 결과, C. polykrikoides 적조와 적조가 아닌 해역이 명확히 구별되었다. 한국 연안에서 발생하는 유해 적조 종의 광 특성 및 이를 바탕으로 제안 된 반사도 밴드 비 구별 방법 등의 분석 결과들은 추후 in-water 적조 탐지 알고리듬 및 위성 적조 탐지 알고리듬 개발을 위한 이론적, 정량적 기준을 제공할 수 있을 것으로 기대된다.List of Tables iv List of Figures v List of Abbreviations viii Abstract x 1. Introduction 1.1 Background 1 1.2 Problem statement 4 1.3 Research aim and approach 8 2. Data and Methods 2.1 Radiometric observations and discrete water samples 9 2.2 Optical parameter measurements 11 2.2.1 Phytoplankton absorption and Chlorophyll a 11 2.2.2 Absorption of colored dissolved organic matter (CDOM) 14 2.3 Hyperspectral Rrs simulation using Hydrolight 15 2.4 Derivative analysis and similarity index 19 3. Results 3.1 Light absorption of HAB species 20 3.2 Comparison of aph in in situ and culture samples 25 3.3 Comparison of hyperspectral remote sensing reflectance (Rrs) 27 3.3.1 in situ Rrs spectra 27 3.3.2 Rrs of HAB species and Unspecified Phytoplankton Assemblages 29 3.3.3 Similarity index between C. polykrikoides and other species 31 3.4 Optical discrimination of C. polykrikoides from other species 33 4. Discussion 36 4.1 Similarity of Rrs(λ) characteristics among dinoflagellate HAB species 37 4.2 Distribution of C. polykrikoides blooms and UPA in Rrs ratio space 39 4.3 Uncertainties in the simulation 42 5. Conclusion 44 Acknowledgements 46 References 48 Appendix A Model input data 55Maste

Harmful algal blooms in the PICES region of the North Pacific

Foreword Background and objectives [pdf, 0.84 MB] Country reviews and status reports Section I. Western North Pacific Japan Yasuwo Fukuyo, Ichiro Imai, Masaaki Kodama and Kyoichi Tamai Red tides and harmful algal blooms in Japan [pdf, 0.7 MB] People's Republic of China Tian Yan, Ming-Jiang Zhou and Jing-Zhong Zou A national report of HABs in China [pdf, 0.24 MB] Republic of Korea Sam Geun Lee, Hak Gyoon Kim, Eon Seob Cho and Chang Kyu Lee Harmful algal blooms (red tides): Management and mitigation in Korea [pdf, 0.27 MB] Russia Tatiana Y. Orlova, Galina V. Konovalova, Inna V. Stonik, Tatiana V. Morozova and Olga G. Shevchenko Harmful algal blooms on the eastern coast of Russia [pdf, 1.4 MB] Section II. Eastern North Pacific Canada F.J.R. "Max" Taylor and Paul J. Harrison Harmful marine algal blooms in western Canada [pdf, 0.87 MB] United States of America Vera L. Trainer Harmful algal blooms on the U.S. west coast [pdf, 0.5 MB] Mexico Jose L. Ochoa, S. Lluch-Cota, B.O. Arredondo-Vega, E. Nuñes-Vázquez, A. Heredia-Tapia, J. Pérez-Linares and R. Alonso-Rodriguez Marine Biotoxins and harmful algal blooms in Mexico's Pacific littora [pdf, 0.2 MB] Summary and conclusions [pdf, 0.6 MB] Appendices A. Members of the Working Group [pdf, 0.1 MB] B. Original terms of reference (Vladivostok, 1999) [pdf, 0.08 MB] C. Annual reports of WG 15 [pdf, 0.15 MB] D. Workshop report on taxonomy and identification of HAB species and data management [pdf, 0.15 MB] (Document pdf contains 156 pages

Remotely Sensed Assessment of the Preferred Habitat of Alexandrium catenella in the Gulf of Maine and the Bay of Fundy

Harmful Algal Blooms (HABs) of the toxic dinoflagellate Alexandrium catenella are an annually recurring problem in the Gulf of Maine (GoM), resulting in risks to human health and substantial economic losses due to shellfish harvesting closures. The monitoring approaches in the region are restricted to real-time identification of the HABs events, when they are clearly underway and already causing deleterious effects to the environment. To fully function as an early warning system rather than an immediate response, monitoring strategies need to be focused on environmental conditions preceding A. catenella HABs. However, the current understanding of the preferred habitat for A. catenella in the GoM is still scarce due to the complex interactions between this organism and the environment. My dissertation research contributes to the solution of these problems by determining the preferred thermal habitat for A. catenella, contrasting environmental conditions for two extremes in A. catenella concentration, and exploring the benefits of using high resolution spectral data to characterize the GoM surface waters. This dissertation is focused on the application of current and future remote sensing technology to the measurement and management of GoM HABs. Chapter 1 briefly introduces the problematic of HABs, monitoring efforts and the study species. Chapter 2 characterizes the interannual variability in the thermal habitat and bloom phenology of A. catenella in the Bay of Fundy, identifying the environmental conditions associated with this variability and its responses to climate change. Chapter 3 contrasts the optical and thermal conditions associated with two extremes in A. catenella concentration over multiple years and areas in the GoM and establishes a set of typical water types for each concentration category. Chapter 4 characterizes the spatial and temporal variability of hyperspectral reflectance of surface waters in the GoM and determines the advantage of hyperspectral resolution over multispectral to identify important spatial patterns and regions. Chapter 5 will conclude with a discussion on the implications of these results to monitoring efforts in the GoM, implications of climate change, and discusses future directives to further explore habitat suitability approaches in monitoring efforts

Earth resources. A continuing bibliography with indexes, issue 23

This bibliography lists 226 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1979 and September 30, 1979. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis