Harmful Algal Blooms in Coastal Waters

Abstract Background Skeletonema species are prominent primary producers, some of which can also cause massive harmful algal blooms (HABs) in coastal waters under specific environmental conditions. Nevertheless, genomic information of Skeletonema species is currently limited, hindering advanced research on their role as primary producers and as HAB species. Mitochondrial genome (mtDNA) has been extensively used as “super barcode” in the phylogenetic analyses and comparative genomic analyses. However, of the 21 accepted Skeletonema species, full-length mtDNAs are currently available only for a single species, S. marinoi. Results In this study, we constructed full-length mtDNAs for six strains of five Skeletonema species, including S. marinoi, S. tropicum, S. grevillei, S. pseudocostatum and S. costatum (with two strains), which were isolated from coastal waters in China. The mtDNAs of all of these Skeletonema species were compact with short intergenic regions, no introns, and no repeat regions. Comparative analyses of these Skeletonema mtDNAs revealed high conservation, with a few discrete regions of high variations, some of which could be used as molecular markers for distinguishing Skeletonema species and for tracking the biogeographic distribution of these species with high resolution and specificity. We estimated divergence times among these Skeletonema species using 34 mtDNAs genes with fossil data as calibration point in PAML, which revealed that the Skeletonema species formed the independent clade diverging from Thalassiosira species approximately 48.30 Mya. Conclusions The availability of mtDNAs of five Skeletonema species provided valuable reference sequences for further evolutionary studies including speciation time estimation and comparative genomic analysis among diatom species. Divergent regions could be used as molecular markers for tracking different Skeletonema species in the fields of coastal regions.

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

Sultan Qaboos University Journal for Science [SQUJS] ◽

10.24200/squjs.vol12iss2pp75-85 ◽

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.

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Dead Zones

10.1093/oso/9780197520376.001.0001 ◽

2021 ◽

Cited By ~ 1

Author(s):

David L. Kirchman

Keyword(s):

Cover Crops ◽

Precision Agriculture ◽

Coastal Waters ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Biological Diversity ◽

Oxygen Depletion ◽

Waterborne Diseases ◽

Buffer Zones ◽

Dead Zones

This book explores the many rivers, lakes, and oceans that are losing oxygen. Aquatic habitats with little dissolved oxygen are called dead zones because nothing can live there except some microbes. The number and size of dead zones are increasing worldwide. The book shows that oxygen loss causes fish kills, devastates bottom-dwelling biota, reduces biological diversity, and rearranges aquatic food webs. In the 19th century in rich countries and in poor regions today, dead zones are accompanied by waterborne diseases that kill thousands of people. The open oceans are losing oxygen because of climate change, whereas dead zones in coastal waters and seas are caused by excessive nutrients, which promote excessive growth of algae and eventually oxygen depletion. Work by Gene Turner and Nancy Rabalais demonstrated that nutrients in the Gulf of Mexico come from fertilizers used in the US Midwest, home to the most productive cropland in the world. Agriculture is also the biggest source of nutrients fuelling dead zones in the Baltic Sea and other coastal waters. Today, fertilizers contaminate drinking water and kick-start harmful algal blooms in local lakes and reservoirs. Nutrient pollution in some regions has declined because of buffer zones, cover crops, and precision agriculture, but more needs to be done. The book concludes by arguing that each of us can do our part by changing our diet; eating less, especially eating less red meat, would improve our health and the health of the environment. A better diet could reduce the amount of greenhouse gas emitted by agriculture and shrink dead zones worldwide.

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