scholarly journals Tracing the sources of nutrients fueling dinoflagellate red tides occurring along the coast of Korea using radium isotopes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hyeong Kyu Kwon ◽  
Guebuem Kim ◽  
Yongjin Han ◽  
Junhyeong Seo ◽  
Weol Ae Lim ◽  
...  

Abstract It is a well held concept that the magnitude of red-tide occurrence is dependent on the amount of nutrient supply if the conditions are same for temperature, salinity, light, interspecific competition, etc. However, nutrient sources fueling dinoflagellate red-tides are difficult to identify since red tides usually occur under very low inorganic-nutrient conditions. In this study, we used short-lived Ra isotopes (223Ra and 224Ra) to trace the nutrient sources fueling initiation and spread of Cochlodinium polykrikoides blooms along the coast of Korea during the summers of 2014, 2016, and 2017. Horizontal and vertical distributions of nutrient concentrations correlated well with 224Ra activities in nutrient-source waters. The offshore red-tide areas showed high 224Ra activities and low-inorganic and high-organic nutrient concentrations, which are favorable for blooming C. polykrikoides in competition with diatoms. Based on Ra isotopes, the nutrients fueling red-tide initiation (southern coast of Korea) are found to be transported horizontally from inner-shore waters. However, the nutrients in the spread region (eastern coast of Korea), approximately 200 km from the initiation region, are supplied continuously from the subsurface layer by vertical mixing or upwelling. Our study highlights that short-lived Ra isotopes are excellent tracers of nutrients fueling harmful algal blooms in coastal waters.

Author(s):  
Hamed Mohammed Al Gheilani ◽  
Kazumi Matsuoka ◽  
Abdulaziz Yahya AlKindi ◽  
Shehla Amer ◽  
Colin Waring

Red tide, one of the harmful algal blooms (HABs) is a natural ecological phenomenon and often this event is accompanied by severe impacts on coastal resources, local economies, and public health. The occurrence of red tides has become more frequent in Omani waters in recent years. Some of them caused fish kill, damaged fishery resources and mariculture, threatened the marine environment and the osmosis membranes of desalination plants. However, a number of them have been harmless. The most common dinoflagellate Noctiluca scintillans is associated with the red tide events in Omani waters. Toxic species like Karenia selliformis, Prorocentrum arabianum, and Trichodesmium erythraeum have also been reported recently. Although red tides in Oman have been considered a consequence of upwelling in the summer season (May to September), recent phytoplankton outbreaks in Oman are not restricted to summer. Frequent algal blooms have been reported during winter (December to March). HABs may have contributed to hypoxia and/or other negative ecological impacts. 


2021 ◽  
Author(s):  
Haoran Li ◽  
Kun Meng ◽  
Qiaojie Yu ◽  
Changping Chen ◽  
Jingfeng Chen ◽  
...  

Abstract In eutrophic waters, harmful algal blooms(HAB) are particularly prone to occur, which will affect the ecological environment and public health and safety. How to quickly detect and monitor marine microalgae is the key to preventing and managing HAB. Our innovative application of colloidal gold immunochromatography(GICG) technology to detect the dominant species in red tide, Skeletonema pseudocostatum, to monitor the outbreak of red tide. The experimental results show that the method and the prepared test strips are extremely sensitive, and can specifically detect the presence of Skeletonema pseudocostatum. The approximate concentration of algae cells is judged by establishing a fitting relationship between the degree of color development and the concentration of algae cells. This test strip provides a quick and easy method for routine environmental monitoring, fishery water quality monitoring, and field testing of red tide monitoring. It effectively warns of the outbreak of red tides and also provides a new application direction for GICG technology.


2020 ◽  
Vol 12 (2) ◽  
pp. 34
Author(s):  
Xiaofan Wang ◽  
Lingyu Xu

Harmful algal blooms (HABs) often cause great harm to fishery production and the safety of human lives. Therefore, the detection and prediction of HABs has become an important issue. Machine learning has been increasingly used to predict HABs at home and abroad. However, few of them can capture the sudden change of Chl-a in advance and handle the long-term dependencies appropriately. In order to address these challenges, the Long Short-Term Memory (LSTM) based spatial-temporal attentions model for Chlorophyll-a (Chl-a) concentration prediction is proposed, a model which can capture the correlation between various factors and Chl-a adaptively and catch dynamic temporal information from previous time intervals for making predictions. The model can also capture the stage of Chl-a when values soar as red tide breaks out in advance. Due to the instability of the current Chl-a concentration prediction model, the model is also applied to make a prediction about the forecast reliability, to have a basic understanding of the range and fluctuation of model errors and provide a reference to describe the range of marine disasters. The data used in the experiment is retrieved from Fujian Marine Forecasts Station from 2009 to 2011 and is combined into 8-dimension data. Results show that the proposed approach performs better than other Chl-a prediction algorithms (such as Attention LSTM and Seq2seq and back propagation). The result of error prediction also reveals that the error forecast method possesses established advantages for red tides prevention and control.


1997 ◽  
Vol 42 (5part2) ◽  
pp. 1076-1088 ◽  
Author(s):  
Rita A. Horner ◽  
David L. Garrison ◽  
F. Gerald Plumley

2012 ◽  
Vol 69 (8) ◽  
pp. 1377-1379 ◽  
Author(s):  
Daniel L. Roelke ◽  
Sofie Spatharis ◽  
Simon M. Mitrovic

Water cycles are changing because of human population growth and climate change. Such changes will affect fundamental system-level characteristics that in turn will greatly influence ecosystem form and functioning. Here, a collection of papers is offered that furthers our understanding of cause and effect relationships between altered hydrology and various ecosystem properties. Combined, these papers address issues related to inflows, connectivity, and circulation and vertical mixing. In regards to altered inflows, this collection of papers addresses how seagrass bed communities, incidence of some haptophyte harmful algal blooms, and biodiversity of intermittently flowing streams might respond. These papers also address factors that influence connectivity in wetlands, and in the case of a lake and its neighboring wetland, how connectivity between systems can profoundly affect ecosystem form and functioning. Finally, the effects of altered circulation and vertical mixing are addressed as they relate to the spread of some cyanobacteria blooms to higher latitudes. The reader of this collection of papers gains a better appreciation of how ecosystem form and functioning is influenced by hydrologic processes and can conclude that there is a need for continued research in this area to better understand the impacts of human population growth and climate change.


EDIS ◽  
2008 ◽  
Vol 2008 (3) ◽  
Author(s):  
Jorge R. Rey

ENY-851, a 5-page illustrated factsheet by Jorge R. Rey, explains what these “harmful algal blooms” are, what causes them, their impacts on marine ecosystems, human health, and coastal economies, and strategies for mitigation and control. Includes references. Published by UF Entomology and Nematology Department, February 2008.


Author(s):  
A.Y.A AlKindi ◽  
H.M.H. Al-Ghelani ◽  
S. Amer ◽  
Y.K Al-Akhzami

The Gulf of Oman, an ecologically and economically rich ecosystem, is frequently impacted by occurrences of harmful algal blooms. Recent studies indicate an increase in the number of causative species and harmful impacts. Many red tide incidents in Oman have been found leading to hypoxia. The frequent bloom forming species here are Karenia selliformis, Nitzschia pungens, Prorocentrum arabianum and Trichodesmium erythraeum. We review work carried out in this area, and we propose here a Management Action Plan for not only an effective monitoring system for harmful algal blooms (HABs), but also mitigation of their adverse impacts and rapid response system.   


2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Raju Reddy ◽  
Nupur Verma ◽  
Tan-Lucien Mohammed

Florida red tides occur annually due to proliferation of the marine dinoflagellate Karenia brevis, which produces neurotoxins known as brevotoxins. Inhalational exposure to brevotoxins usually results in upper airway symptoms only. Rarely does exposure lead to lower respiratory tract symptoms as in our case. We report a case of a 50-year-old man who presented with a 4-week history of dyspnea after exposure to the red tide. Computed tomography (CT) of the chest showed diffuse bilateral ground glass opacities and interstitial thickening. Bronchoalveolar lavage cultures and cytology were negative. The patient was started on steroids. Over the next few weeks, the patient’s symptoms resolved. Repeat CT chest showed complete resolution of the ground glass opacities. Steroids were then tapered. Most patients who are exposed to algal blooms have self-limiting symptoms. Patients with asthma are particularly susceptible to worsening respiratory symptoms after exposure to brevotoxin aerosols. This case highlights that, in rare cases, exposure to red tide can results in severe lower respiratory tract symptoms.


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