Combating Red Tides in Harbors

10.1142/12638 ◽  
2023 ◽  
Author(s):  
Weidong Ji ◽  
Cai Lin ◽  
Kuncan Xu ◽  
Baohong Chen ◽  
Guobiao Ji ◽  
...  
Keyword(s):  
Red Tides

scholarly journals Feeding diverse prey as an excellent strategy of mixotrophic dinoflagellates for global dominance

2021 ◽  
Vol 7 (2) ◽  
pp. eabe4214
Author(s):  
Hae Jin Jeong ◽  
Hee Chang Kang ◽  
An Suk Lim ◽  
Se Hyeon Jang ◽  
Kitack Lee ◽  
...  
Keyword(s):  
Genetic Factor ◽  
Red Tide ◽  
Biogeochemical Cycles ◽  
Evolutionary Strategy ◽  
Distribution Data ◽  
Red Tides ◽  
Trade Off ◽  
Moderate Growth ◽  
Prey Diversity ◽  
Standing Question

Microalgae fuel food webs and biogeochemical cycles of key elements in the ocean. What determines microalgal dominance in the ocean is a long-standing question. Red tide distribution data (spanning 1990 to 2019) show that mixotrophic dinoflagellates, capable of photosynthesis and predation together, were responsible for ~40% of the species forming red tides globally. Counterintuitively, the species with low or moderate growth rates but diverse prey including diatoms caused red tides globally. The ability of these dinoflagellates to trade off growth for prey diversity is another genetic factor critical to formation of red tides across diverse ocean conditions. This finding has profound implications for explaining the global dominance of particular microalgae, their key eco-evolutionary strategy, and prediction of harmful red tide outbreaks.

scholarly journals High Spatial-Resolution Red Tide Detection in the Southern Coast of Korea Using U-Net from PlanetScope Imagery

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4447
Author(s):  
Jisun Shin ◽  
Young-Heon Jo ◽  
Joo-Hyung Ryu ◽  
Boo-Keun Khim ◽  
Soo Mee Kim
Keyword(s):  
Deep Learning ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Red Tide ◽  
Learning Approaches ◽  
Red Tides ◽  
Southern Coast ◽  
Color Sensors ◽  
Deep Learning Model ◽  
Bloom Water

Red tides caused by Margalefidinium polykrikoides occur continuously along the southern coast of Korea, where there are many aquaculture cages, and therefore, prompt monitoring of bloom water is required to prevent considerable damage. Satellite-based ocean-color sensors are widely used for detecting red tide blooms, but their low spatial resolution restricts coastal observations. Contrarily, terrestrial sensors with a high spatial resolution are good candidate sensors, despite the lack of spectral resolution and bands for red tide detection. In this study, we developed a U-Net deep learning model for detecting M. polykrikoides blooms along the southern coast of Korea from PlanetScope imagery with a high spatial resolution of 3 m. The U-Net model was trained with four different datasets that were constructed with randomly or non-randomly chosen patches consisting of different ratios of red tide and non-red tide pixels. The qualitative and quantitative assessments of the conventional red tide index (RTI) and four U-Net models suggest that the U-Net model, which was trained with a dataset of non-randomly chosen patches including non-red tide patches, outperformed RTI in terms of sensitivity, precision, and F-measure level, accounting for an increase of 19.84%, 44.84%, and 28.52%, respectively. The M. polykrikoides map derived from U-Net provides the most reasonable red tide patterns in all water areas. Combining high spatial resolution images and deep learning approaches represents a good solution for the monitoring of red tides over coastal regions.

Chemical environment for red tides due toChattonella antiqua

1989 ◽  
Vol 45 (2) ◽  
pp. 116-128 ◽  
Author(s):  
Yasuo Nakamura ◽  
Tatsushi Umemori ◽  
Masataka Watanabe
Keyword(s):  
Chemical Environment ◽  
Red Tides

scholarly journals Investigation of the Inhibitory Effects of Mangrove Leaves and Analysis of Their Active Components on Phaeocystis globosa during Different Stages of Leaf Age

2018 ◽  
Vol 15 (11) ◽  
pp. 2434 ◽  
Author(s):  
Min Zhao ◽  
Han Xiao ◽  
Dong Sun ◽  
Shunshan Duan
Keyword(s):  
Secondary Metabolites ◽  
Harmful Algae ◽  
Marine Ecology ◽  
Phenolic Glycoside ◽  
Aqueous Extracts ◽  
Red Tides ◽  
Inhibitory Effects ◽  
Phaeocystis Globosa ◽  
Biological Remediation ◽  
Young Leaves

The presence of harmful algal blooms (HABs) can cause significant problems to the quality of the water, the marine ecosystems, and the human health, and economy worldwide. Biological remediation can inhibit harmful algal growth efficiently in an environmental-friendly manner. Therefore, the research conducted on biological remediation with regard to the inhibition of HABs is becoming a major focus in marine ecology. To date, no study has been reported with regard to the red tides occurring in mangrove wetlands. Therefore, the present study used two mangrove species, namely Bruguiera gymnorrhiza and Kandelia candel and one harmful algae species Phaeocystis globosa as experimental organisms. The present study determined the inhibitory effects and algae physiology of specific aqueous extracts from mangrove leaves on the viability of harmful algae, and analyzed the main chemical composition of the aqueous extracts by ultra-performance liquid chromatography coupled to high resolution mass spectrometry (UPLC-QTOF-MS). The results indicated that the aqueous extracts from different leaf ages of B. gymnorrhiza and K. candel leaves exhibited apparent inhibitory effects on the growth of P. globosa. The inhibitory effects of B. gymnorrhiza and K. candel leaves aqueous extracts on the growth of P. globosa were in the following order: senescent > mature > young leaves. The levels of the parameters superoxide dismutase (SOD) activity, glutathione (GSH), and malondialdehyde (MDA)content in P. globosa following treatment with B. gymnorrhiza and K. candel leaves aqueous extracts were increased as follows: senescent > mature > young leaves. Simultaneously, the intensity of the ion peaks of the specific secondary metabolites assigned 4 (No.: 4 Rt: 2.83 min), 7 (No.: 7 Rt: 3.14 min), 8 (No.: 8 Rt: 3.24 min), 9 (No.: 9 Rt: 3.82min) and 10 (No.: 10 Rt: 4.10 min) were increased. These metabolites were found in the aqueous extracts from B. gymnorrhiza leaves. The intensities of the ion peaks of the secondary metabolites 7, 8 in the aqueous extracts from the K. candel leaves were also increased. The majority of the substances that inhibited the algae found in the mangrove plants were secondary metabolites. Therefore, we considered that the norsesquiterpenes compounds 4, 8, 9, and 10 and a phenolic glycoside compound 7 were the active constituents in the aqueous extracts of the mangrove leaves responsible for the inhibition of algae growth. This evidence provided theoretical guidance for the development of biological methods to control red tides and for the further use of substances with antiproliferative activity against algae.

Hong Kong: Toxic red tides again!

1991 ◽  
Vol 22 (1) ◽  
pp. 4 ◽  
Author(s):  
John Hodgkiss ◽  
K.C. Ho
Keyword(s):  
Hong Kong ◽  
Red Tides

scholarly journals Coastal Ocean Physics and Red Tides: An Example from Monterey Bay, California

Oceanography ◽  
2005 ◽  
Vol 18 (2) ◽  
pp. 246-255 ◽  
Author(s):  
John Ryan ◽  
Heidi Dierssen ◽  
Raphael Kudela ◽  
Christopher Scholin ◽  
Kenneth Johnson ◽  
...  
Keyword(s):  
Coastal Ocean ◽  
Monterey Bay ◽  
Red Tides ◽  
Ocean Physics

scholarly journals Role of Aerosolized Coal Fly Ash in the Global Plankton Imbalance: Case of Florida's Toxic Algae Crisis

2019 ◽  
pp. 1-24
Author(s):  
Mark Whiteside ◽  
J. Marvin Herndon
Keyword(s):  
Fly Ash ◽  
Marine Mammals ◽  
Salt Water ◽  
Harmful Algal Bloom ◽  
Coal Fly Ash ◽  
Harmful Algae ◽  
Cyanobacterial Blooms ◽  
Red Tides ◽  
Blue Green Algae ◽  
Tropospheric Aerosol

Red tide is the term used in Florida (USA) and elsewhere to describe a type of marine harmful algal bloom (HAB) that grows out of control and produces neurotoxins that adversely affect humans, birds, fish, shellfish, and marine mammals. HABs are becoming more abundant, extensive, and closer to shore, and longer in duration than any time in recorded history. Our objective is to review the effects the multifold components of aerosolized coal fly ash as they relate to the increasing occurrences of HABs. Aerosolized coal fly ash (CFA) pollutants from non-sequestered coal-fired power plant emissions and from undisclosed, although “hidden in plain sight,” tropospheric particulate geoengineering operations are inflicting irreparable damage to the world’s surface water-bodies and causing great harm to human health (including lung cancer, respiratory and neurodegenerative diseases) and environmental health (including major die-offs of insects, birds and trees). Florida’s ever-growing toxic nightmare of red tides and blue-green algae is a microcosm of similar activity globally. Atmospheric deposition of aerosol particulates, most importantly bioavailable iron, has drastically shifted the global plankton community balance in the direction of harmful algae and cyanobacterial blooms in fresh and salt water. Proposed geoengineering schemes of iron fertilization of the ocean would only make a bad situation unimaginably worse. Based on the evidence presented here, the global spread of harmful algae blooms will only be contained by rapidly reducing particulate air pollution both by implementation of universal industrial particulate-trapping and by the immediate halting of jet-sprayed particulate aerosols. Corrective actions depend not only on international cooperation, but on ending the deadly code of silence throughout government, academe, and media on the subject of ongoing tropospheric aerosol geoengineering. Long-standing weather control, climate intervention, and geoengineering operations have come to threaten not only all humans but the entire web of life on Earth.

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