scholarly journals Hydrographical Observations during a Red Tide with Fish Mortalities at Masirah Island, Oman

2008 ◽  
Vol 13 ◽  
pp. 64 ◽  
Author(s):  
Saud S. Al Busaidi ◽  
Khalfan M. Al Rashdi ◽  
Hamed M. Al Gheilani ◽  
Shehla Amer
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Red Tide ◽  
Fish Mortality ◽  
Noctiluca Scintillans ◽  
Trichodesmium Erythraeum ◽  
Fish Samples ◽  
Marine Dinoflagellates ◽  
Toxic Blooms ◽  
Human Poisoning

Harmful Algal Blooms (HABs) can have a significant impact on the distribution and  survival of coastal fishes and invertebrates, and consequently they can affect local economies where fishing is an important activity. In October 2005, extensive algal blooms with brownish/orange discoloured water and fish mortalities were observed east of Masirah Island. Satellite images revealed cooler upwelled surface water along a broad front just prior to the event, followed by a gradual warming period coinciding with the mortalities. Depth profiles of dissolved oxygen (DO), temperature, salinity and pH taken on 19th October (during the fish mortality event) showed a pronounced thermocline at ~15 m depth and minimum DO of 0.82 ml/L at 25 m depth, and a slight improvement in DO to 1.3 ml/L was measured on 22nd October (after the event). Demersal fishes of several families were prominent among mortalities. No bacterial infestation was found in fish samples and no human poisoning was reported. Planktological data showed that marine dinoflagellates Noctiluca scintillans and  Prorocentrum micans and toxic blooms of cyanobacterium Trichodesmium erythraeum were present.

scholarly journals Fish Kill Incidents and Harmful Algal Blooms in Omani Waters

2011 ◽  
Vol 16 ◽  
pp. 23 ◽  
Author(s):  
Hamed Mohammed Al Gheilani ◽  
Kazumi Matsuoka ◽  
Abdulaziz Yahya AlKindi ◽  
Shehla Amer ◽  
Colin Waring
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Red Tide ◽  
Ecological Impacts ◽  
Red Tides ◽  
Fish Kill ◽  
Noctiluca Scintillans ◽  
Trichodesmium Erythraeum ◽  
Toxic Species ◽  
Desalination Plants

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. 

scholarly journals Action Plan for Monitoring, Mitigation and Management of Harmful Algal Blooms in the Coastal Waters of Oman

2007 ◽  
Vol 12 (2) ◽  
pp. 75
Author(s):  
A.Y.A AlKindi ◽  
H.M.H. Al-Ghelani ◽  
S. Amer ◽  
Y.K Al-Akhzami
Keyword(s):  
Coastal Waters ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Red Tide ◽  
Action Plan ◽  
Rapid Response System ◽  
Gulf Of Oman ◽  
Trichodesmium Erythraeum ◽  
Response System ◽  
Adverse Impacts

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.   

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 ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Red Tide ◽  
Subsurface Layer ◽  
Vertical Mixing ◽  
Eastern Coast ◽  
Nutrient Concentrations ◽  
Red Tides ◽  
Radium Isotopes ◽  
Nutrient Sources

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.

scholarly journals Harmful algal blooms and red tide problems on the U.S. west coast

1997 ◽  
Vol 42 (5part2) ◽  
pp. 1076-1088 ◽  
Author(s):  
Rita A. Horner ◽  
David L. Garrison ◽  
F. Gerald Plumley
Keyword(s):  
West Coast ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Red Tide ◽  
The U.S

Preliminary Development of a Competitive Fluorescent Quantum Dot-Based Immunochromatographic Test Strip for Sensitive Saxitoxin Detection

2020 ◽  
Vol 18 (6) ◽  
pp. 459-463
Author(s):  
John G. Bruno ◽  
Jeremy John
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Dynamic Range ◽  
Red Tide ◽  
Coupling Reaction ◽  
Test Strip ◽  
Paralytic Shellfish Poisoning ◽  
Shellfish Poisoning ◽  
Band Shift ◽  
Portable Detection

Rapid and portable detection of saxitoxin (STX) and its many congeners is highly desirable to prevent paralytic shellfish poisoning due to red tide or harmful algal blooms. In this work, we describe successful preliminary efforts to develop a very sensitive general STX family test strip employing highly fluorescent red quantum dots (Qdot 655) to detect as little as 0.5 to 1 part per billion (ppb or ng/ml) of STX with a dynamic range extending to 20,000 ppb after the prototype dipstick assay was optimized. A competitive format was necessitated by the small molecule nature of STXs having only one epitope, but the decrease in Qdot fluorescence was clearly visible to the naked eye as a function of increasing STX concentration in aqueous buffer. The competitive displacement assay format required conjugation of a primary amine in STX to carboxyl-Qdot 655 via a covalent carbodiimide coupling reaction which was validated by an electrophoretic mobility band shift assay.

scholarly journals A Novel Cyclophilin B Gene in the Red Tide DinoflagellateCochlodinium polykrikoides: Molecular Characterizations and Transcriptional Responses to Environmental Stresses

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Sofia Abassi ◽  
Hui Wang ◽  
Bum Soo Park ◽  
Jong-Woo Park ◽  
Jang-Seu Ki
Keyword(s):  
Stress Responses ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Red Tide ◽  
Economic Loss ◽  
Cell Physiology ◽  
Transcriptional Responses ◽  
Splice Leader ◽  
Cyclophilin B ◽  
Cell Counts

The marine dinoflagellateCochlodinium polykrikoidesis one of the most common ichthyotoxic species that causes harmful algal blooms (HABs), which leads to ecological damage and huge economic loss in aquaculture industries. Cyclophilins (CYPs) belong to the immunophilin superfamily, and they may play a role in the survival mechanisms of the dinoflagellate in stress environments. In the present study, we identified a novel cyclophilin gene fromC. polykrikoidesand examined physiological and gene transcriptional responses to biocides copper sulphate (CuSO4) and sodium hypochlorite (NaOCl). The full length ofCpCYPwas 903 bp, ranging from the dinoflagellate splice leader (DinoSL) sequence to the polyA tail, comprising a 639 bp ORF, a 117 bp 5′-UTR, and a 147 bp 3′-UTR. Motif and phylogenetic comparisons showed that CpCYP was affiliated to group B of CYP. In biocide stressors, cell counts, chlorophylla, and photosynthetic efficiency (Fv/Fm) ofC. polykrikoideswere considerably decreased in both exposure time- and dose-dependent manners. In addition,CpCYPgene expression was significantly induced after 24 h exposure to the biocide-treated stress conditions. These results indicate an effect of the biocides on the cell physiology and expression profile ofCpCYP, suggesting that the gene may play a role in environmental stress responses.

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