scholarly journals Assessing the Use of Molecular Barcoding and qPCR for Investigating the Ecology of Prorocentrum minimum (Dinophyceae), a Harmful Algal Species

2021 ◽  
Vol 9 (3) ◽  
pp. 510
Author(s):  
Kate McLennan ◽  
Rendy Ruvindy ◽  
Martin Ostrowski ◽  
Shauna Murray
Keyword(s):  
Light Microscopy ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
High Throughput Sequencing ◽  
Algal Species ◽  
Amplicon Sequencing ◽  
Prorocentrum Minimum ◽  
Molecular Barcoding ◽  
Phytoplankton Diversity ◽  
Abundance Estimates

Prorocentrum minimum is a species of marine dinoflagellate that occurs worldwide and can be responsible for harmful algal blooms (HABs). Some studies have reported it to produce tetrodotoxin; however, results have been inconsistent. qPCR and molecular barcoding (amplicon sequencing) using high-throughput sequencing have been increasingly applied to quantify HAB species for ecological analyses and monitoring. Here, we isolated a strain of P. minimum from eastern Australian waters, where it commonly occurs, and developed and validated a qPCR assay for this species based on a region of ITS rRNA in relation to abundance estimates from the cultured strain as determined using light microscopy. We used this tool to quantify and examine ecological drivers of P. minimum in Botany Bay, an estuary in southeast Australia, for over ~14 months in 2016–2017. We compared abundance estimates using qPCR with those obtained using molecular barcoding based on an 18S rRNA amplicon. There was a significant correlation between the abundance estimates from amplicon sequencing and qPCR, but the estimates from light microscopy were not significantly correlated, likely due to the counting method applied. Using amplicon sequencing, ~600 unique actual sequence variants (ASVs) were found, much larger than the known phytoplankton diversity from this region. P. minimum abundance in Botany Bay was found to be significantly associated with lower salinities and higher dissolved CO2 levels.

scholarly journals Diversity of dinoflagellate assemblages in coastal temperate and offshore tropical waters of Australia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tahnee Manning ◽  
Arjun Venkatesh Thilagaraj ◽  
Dmitri Mouradov ◽  
Richard Piola ◽  
Clare Grandison ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
High Throughput ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
High Throughput Sequencing ◽  
Environmental Parameters ◽  
Marine Phytoplankton ◽  
Tropical Waters ◽  
Total Sequence ◽  
Phytoplankton Communities

Abstract Background Dinoflagellates are a ubiquitous and ecologically important component of marine phytoplankton communities, with particularly notable species including those associated with harmful algal blooms (HABs) and those that bioluminesce. High-throughput sequencing offers a novel approach compared to traditional microscopy for determining species assemblages and distributions of dinoflagellates, which are poorly known especially in Australian waters. Results We assessed the composition of dinoflagellate assemblages in two Australian locations: coastal temperate Port Phillip Bay and offshore tropical waters of Davies Reef (Great Barrier Reef). These locations differ in certain environmental parameters reflecting latitude as well as possible anthropogenic influences. Molecular taxonomic assessment revealed more species than traditional microscopy, and it showed statistically significant differences in dinoflagellate assemblages between locations. Bioluminescent species and known associates of HABs were present at both sites. Dinoflagellates in both areas were mainly represented by the order Gymnodiniales (66%—82% of total sequence reads). In the warm waters of Davies Reef, Gymnodiniales were equally represented by the two superclades, Gymnodiniales sensu stricto (33%) and Gyrodinium (34%). In contrast, in cooler waters of Port Phillip Bay, Gymnodiniales was mainly represented by Gyrodinium (82%). In both locations, bioluminescent dinoflagellates represented up to 0.24% of the total sequence reads, with Protoperidinium the most abundant genus. HAB-related species, mainly represented by Gyrodinium, were more abundant in Port Phillip Bay (up to 47%) than at Davies Reef (28%), potentially reflecting anthropogenic influence from highly populated and industrial areas surrounding the bay. The entire assemblage of dinoflagellates, as well as the subsets of HAB and bioluminescent species, were strongly correlated with water quality parameters (R2 = 0.56–0.92). Significant predictors differed between the subsets: HAB assemblages were explained by salinity, temperature, dissolved oxygen, and total dissolved solids; whereas, bioluminescent assemblages were explained only by salinity and dissolved oxygen, and had greater variability. Conclusion High-throughput sequencing and genotyping revealed greater diversity of dinoflagellate assemblages than previously known in both subtropical and temperate Australian waters. Significant correlations of assemblage structure with environmental variables suggest the potential for explaining the distribution and composition of both HAB species and bioluminescent species.

scholarly journals Cyanoprokaryotes biodiversity in nine shallow Bulgarian wetlands

2019 ◽  
Vol 2 ◽  
Author(s):  
Blagoy Uzunov ◽  
Maya Stoyneva-Gärtner ◽  
Georg Gärtner ◽  
Mariana Radkova ◽  
Katerina Stefanova
Keyword(s):  
Light Microscopy ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Molecular Methods ◽  
Geographical Pattern ◽  
Algal Toxins ◽  
The Real ◽  
Total Phytoplankton ◽  
Toxigenic Strains ◽  
Conventional Light Microscopy

The results from the investigation of the phytoplankton in nine shallow wetlands, situated in Central and Eastern Bulgaria, conducted in the frame of recent projects related to identifying harmful algal blooms and algal toxins in the country are demonstrated. Therefore, the focus is on the cyanoprokaryotes and their toxigenic species in particular. The species were identified using conventional light microscopy, while for distinguishing the toxigenic species and strains PCR-based molecular methods were applied. Cyanoprokaryotes comprised about 30% of the total phytoplankton biodiversity of the studied wetlands and were unevenly spread among them. The presence and spread of toxigenic strains in the studied wetlands also did not show any strong geographical pattern. Taxonomic problems related with the evaluation of the real cyanoprokaryotic biodiversity and potential alien or invasive character of the morphospecies are discussed.

scholarly journals Harmful Algal Blooms: Physiology, Behavior, Population Dynamics and Global Impacts- A Review

2005 ◽  
Vol 10 ◽  
pp. 1
Author(s):  
H.M. Al-Ghelani ◽  
A.Y.A AlKindi ◽  
S. Amer ◽  
Y.K Al-Akhzami
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Global Climate ◽  
Algal Species ◽  
Molecular Probes ◽  
Screening Methods ◽  
Global Climate Changes ◽  
Global Impacts ◽  
Anthropogenic Loading ◽  
Global Increase

Harmful, toxic algae are now considered as one of the important players in the newly emerging environmental risk factors. The apparent global increase in harmful algal blooms (HABs) is becoming a serious problem in both aquaculture and fisheries populations. Not only has the magnitude and intensity of public health and economic impacts of these blooms increased in recent years, but the number of geographic locations experiencing toxic algal blooms has also increased dramatically. There are two primary factors causing HABs outbreaks. The natural processes such as upwelling and relaxation, and the anthropogenic loading resulting in eutrophication. However, the influence of global climate changes on algal bloom phenomenon cannot be ignored. The problem warrants development of effective strategies for the management and mitigation of HABs. Progress made in the routine coastal monitoring programs, development of methods for detection of algal species and toxins and coastal modeling activities for predicting HABs reflect the international concerns regarding the impacts of HABs. Innovative techniques using molecular probes will hopefully result in development of rapid, reliable screening methods for phycotoxins and the causative organisms.            

scholarly journals Comparison of Short-Term Toxicity of 14 Common Phycotoxins (Alone and in Combination) To The Survival of Brine Shrimp Artemia Salina

2021 ◽  
Author(s):  
Yu Ting Zhang ◽  
Shanshan SONG ◽  
Bin ZHANG ◽  
Yang ZHANG ◽  
Miao TIAN ◽  
...  
Keyword(s):  
Ecological Risk ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Algal Species ◽  
Natural Populations ◽  
Marine Ecosystems ◽  
Artemia Salina ◽  
Marine Organisms ◽  
Short Term ◽  
The Impact

Abstract Toxic harmful algal blooms (HABs) can cause deleterious effects in marine organisms, threatening the stability of marine ecosystems. It is well known that different strains, natural populations and growth conditions of the same toxic algal species may lead to different amount of phycotoxin production and the ensuing toxicity. To fully assess the ecological risk of toxic HABs, it is of great importance to investigate the toxic effects of phycotoxins in marine organisms. In this study, the short-term toxicity of 14 common phycotoxins (alone and in combination) in the marine zooplankton Artemia salina was investigated. On the basis of 48 h LC50, the order of toxicity in A. salina was AZA3 (with a LC50 of 0.0203 µg/ml)＞AZA2 (0.0273 µg/ml) ＞PTX2 (0.0396 µg/ml)＞DTX1 (0.0819 µg/ml)＞AZA1 (0.106 µg/ml)＞ SPX1 (0.144 µg/ml)＞YTX (0.172 µg/ml)＞dcSTX (0.668 µg/ml)＞OA (0.728 µg/ml)＞STX (1.042 µg/ml)＞GYM (1.069 µg/ml)＞PbTx3 (1.239 µg/ml)＞hYTX (1.799 µg/ml)＞PbTx2 (2.415 µg/ml). For the binary exposure, additive effects of OA and DTX1, DTX1 and hYTX; antagonistic effects of OA and PTX2, OA and STX; and synergetic effects of DTX1 and STX, DTX1 and YTX, DTX1 and PTX2, PTX2 and hYTX on the mortality of A. salina were observed. These results provide valuable toxicological data for assessing the impact of phycotoxins on marine planktonic species and highlight the potential ecological risk of toxic HABs in marine ecosystems.

scholarly journals Review of Harmful Algal Blooms in the Coastal Mediterranean Sea, with a Focus on Greek Waters

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 396
Author(s):  
Christina Tsikoti ◽  
Savvas Genitsaris
Keyword(s):  
Mediterranean Sea ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Ecosystem Health ◽  
Algal Species ◽  
Coastal Areas ◽  
Population Increase ◽  
Nutrient Inputs ◽  
Environmental Pressures ◽  
Marine Eutrophication

Anthropogenic marine eutrophication has been recognized as one of the major threats to aquatic ecosystem health. In recent years, eutrophication phenomena, prompted by global warming and population increase, have stimulated the proliferation of potentially harmful algal taxa resulting in the prevalence of frequent and intense harmful algal blooms (HABs) in coastal areas. Numerous coastal areas of the Mediterranean Sea (MS) are under environmental pressures arising from human activities that are driving ecosystem degradation and resulting in the increase of the supply of nutrient inputs. In this review, we aim to present the recent situation regarding the appearance of HABs in Mediterranean coastal areas linked to anthropogenic eutrophication, to highlight the features and particularities of the MS, and to summarize the harmful phytoplankton outbreaks along the length of coastal areas of many localities. Furthermore, we focus on HABs documented in Greek coastal areas according to the causative algal species, the period of occurrence, and the induced damage in human and ecosystem health. The occurrence of eutrophication-induced HAB incidents during the past two decades is emphasized.

Occurrence characteristics of harmful and non-harmful algal species related to coastal environments in the southern sea of Korea

2019 ◽  
Vol 70 (6) ◽  
pp. 794 ◽  
Author(s):  
Jin Ho Kim ◽  
Minji Lee ◽  
Young Kyun Lim ◽  
Yun Ji Kim ◽  
Seung Ho Baek
Keyword(s):  
South Korea ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Phytoplankton Community ◽  
Algal Species ◽  
Coastal Environments ◽  
Survey Period ◽  
Offshore Area ◽  
Occurrence Characteristics ◽  
Hab Species

Because the phytoplankton community and blooms are regulated by various environmental factors, it is difficult to define the cause and occurrence of the phenomenon of harmful algal blooms (HABs). This study evaluated the phytoplankton community and occurrence characteristic of HAB species related to coastal environments in South Korea, 2016. In summer, because of strong upwelling event, the surface sweater temperature around Geoje Island was abnormally low (17°C), and an unusual high temperature (29°C) and low salinity (29psu) were measured in offshore area. Diatoms and dinoflagellates showed contrasting occurrences during the survey period. Diatoms were dominant in the inshore area, whereas dinoflagellates occurred in the offshore area. The phytoplankton-community structures were established depending on different hydro-oceanographic characteristics. In statistical analysis, HABs of dinoflagellate Karenia appeared in upwelling areas with a high nutritional content, whereas Gymnodinium, Gyrodinium and Prorocentrum appeared in areas of low nutrients in June, and HAB species showed an equivalent tendency to appear at high water temperature and low saline level in August. Our results indicated that hydro-oceanographic events such as river discharge, current and upwelling play important roles in determining the phytoplankton community and potential occurrence characteristics of HABs in the coastal environment of South Korea.

scholarly journals Bacterial Composition Associated With Giant Colonies of the Harmful Algal Species Phaeocystis globosa

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhu Zhu ◽  
Rui Meng ◽  
Walker O. Smith Jr. ◽  
Hai Doan-Nhu ◽  
Lam Nguyen-Ngoc ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Algal Species ◽  
Microbial Consortia ◽  
Colony Development ◽  
Microbial Composition ◽  
Phaeocystis Globosa ◽  
Ambient Seawater ◽  
Bacterial Composition ◽  
Bacterial Consortia

The cosmopolitan algae Phaeocystis globosa forms harmful algal blooms frequently in a number of tropical and subtropical coastal regions in the past two decades. During the bloom, the giant colony, which is formed by P. globosa, is the dominant morphotype. However, the microenvironment and the microbial composition in the intracolonial fluid are poorly understood. Here, we used high-throughput 16S rRNA amplicon sequencing to examine the bacterial composition and predicted functions in intracolonial fluid. Compared with the bacterial consortia in ambient seawater, intracolonial fluids possessed the lower levels of microbial richness and diversity, implying selectivity of bacteria by the unique intracolonial microenvironment enclosed within the P. globosa polysaccharide envelope. The bacterial consortia in intracolonial fluid were dominated by Balneola (48.6% of total abundance) and Labrezia (28.5%). The bacteria and microbial function enriched in intracolonial fluid were involved in aromatic benzenoid compounds degradation, DMSP and DMS production and consumption, and antibacterial compounds synthesis. We suggest that the P. globosa colonial envelope allows for the formation of a specific microenvironment; thus, the unique microbial consortia inhabiting intracolonial fluid has close interaction with P. globosa cells, which may benefit colony development.

scholarly journals A prolonged red tide of Heterocapsa triquetra (Ehrenberg) F. Stein (Dinophyceae) and phytoplankton succession in a eutrophic estuary in Turkey

2015 ◽  
Vol 16 (3) ◽  
pp. 621 ◽  
Author(s):  
S. TAS
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Red Tide ◽  
Prorocentrum Minimum ◽  
Phytoplankton Succession ◽  
Chl A ◽  
Heterocapsa Triquetra ◽  
Golden Horn ◽  
Moderate Salinity ◽  
Near Future

A prolonged red tide of Heterocapsa triquetra and phytoplankton succession were investigated in a eutrophic estuary (Golden Horn) for a year. Runoff following the rainfall in winter supplied high amounts of nutrients and also created a mesohaline frontal zone in the middle and upper estuary. Red tide of H. triquetra was first observed with an orange-brownish water discoloration at the upper estuary in January. Highest cell density of H. triquetra was 2.7×106 cells l-1 in January and reached to 19.2×106 cells l-1 in April. Successive blooms continued with dinoflagellate Prorocentrum minimum in May and phytoflagellates Eutreptiella marina and Fibrocapsa sp. in summer. High chl-a and dissolved oxygen were measured in the spring depending on algal biomass. Findings indicate that H. triquetra might be adapted to moderate salinity and low temperatures and red tide events should be considered as a response to increasing eutrophication due to high amounts of nutrients. Eutrophication can lead to harmful algal blooms for this area in the near future.

Importance of free-living and particle-associated bacteria for the growth of the harmful dinoflagellate Prorocentrum minimum: evidence in culture stages

2018 ◽  
Vol 69 (2) ◽  
pp. 290 ◽  
Author(s):  
Bum Soo Park ◽  
Ruoyu Guo ◽  
Weol-Ae Lim ◽  
Jang-Seu Ki
Keyword(s):  
Bacterial Community ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Bacterial Community Composition ◽  
Hierarchical Cluster ◽  
Prorocentrum Minimum ◽  
Growth Stages ◽  
Roseobacter Clade ◽  
Free Living ◽  
Associated Bacteria

The marine dinoflagellate Prorocentrum minimum is the cause of harmful algal blooms and may grow in association with co-occurring bacteria as ectosymbiotic, endosymbiotic and free-living forms. In the present study we investigated the bacterial community composition of both free-living bacteria (FLB) and particle-associated bacteria (PAB) in the lag, exponential and stationary growth stages of P. minimum using pyrosequencing. Metagenomics, hierarchical cluster and non-metric multidimensional scaling analyses revealed that FLB and PAB had significantly different bacterial community compositions. The PAB community had greater taxonomic richness and diversity than the FLB community. In addition, the shared bacteria identified were clearly dominant in both the FLB (≥98.2%) and PAB (≥89.9%) communities. Among shared bacteria, the genera Seohaeicola (P. minimum operational taxonomic unit (OTU) #1) and Roseovarius (P. minimum OTU #6), belonging to the Roseobacter clade, were predominant in FLB (42–57%) and PAB (11–14%) communities respectively. In the PAB community, the Marinobacter clade (P. minimum OTU #13 and #15) was also a dominant taxon. Interestingly, in response to the growth of P. minimum, the proportion of the Roseobacter clade increased gradually, whereas the genus Marinobacter decreased in both the FLB and PAB communities. These results suggest that Roseobacter and Marinobacter clades are intimately associated with host dinoflagellate.

scholarly journals Spatiotemporal Distribution of Harmful Algal Flora in the Tropical Estuarine Complex of Goa, India

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Suraksha M. Pednekar ◽  
S. G. Prabhu Matondkar ◽  
Vijaya Kerkar
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Nutrient Loading ◽  
Algal Species ◽  
Spatiotemporal Variability ◽  
Algal Flora ◽  
The Past ◽  
Tropical Estuarine ◽  
Mandovi And Zuari Estuaries ◽  
Hab Species

Mandovi and Zuari estuarine complex is monsoon-influenced estuaries located along the central west coast of India. During the past few years, there has been an increase in nutrient loading specially during monsoonal runoff which is responsible for the growth of harmful algal flora. To understand occurrence and distribution of harmful algal blooms species, daily/alternate day samplings were carried out in Mandovi and Zuari estuaries during 2007-2008 and 2008-2009 periods, respectively, comprising of monsoon (June–November) and nonmonsoon (December–May). In Mandovi, total 54 HAB species with 49 in monsoon and 36 during nonmonsoon period were reported. In Zuari, total 46 HAB species with 38 in monsoon and 41 were reported during nonmonsoon period. Bray-Curtis cluster analysis based on log-transformed phytoplankton density detected seven well-defined groups revealing spatiotemporal variability. The density of the dominant harmful algal species was significantly positively correlated with nutrients, but negatively correlated with salinity. The results of the study indicate that monsoon plays an important role in occurrence and distribution of harmful algal species having direct correlation with salinity variations and nutrient loading.

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