Harmful Algal Blooms and Microalgae from Ecology to Control Strategies

A special issue of Toxins (ISSN 2072-6651). This special issue belongs to the section "Marine and Freshwater Toxins".

Deadline for manuscript submissions: closed (30 November 2023) | Viewed by 10686

Special Issue Editors


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Guest Editor
Centro de Investigacións Científicas Avanzadas (CICA), Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Spain
Interests: phycology

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Guest Editor
1. CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Pólo dos Açores - Faculdade de Ciências e Tecnologias, Universidade dos Açores, R. Mãe de Deus 13A, 9500-321 Ponta Delgada, Portugal
2. BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
Interests: freshwater ecology; ecological quality assessment; environmental monitoring; environmental reconstruction; cyanobacteria; microalgae; diatoms; blue biotechnology; algae culture; litter decomposition
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Special Issue Information

Dear Colleagues,

The rise of harmful algal blooms (HABs) in aquatic ecosystems worldwide is among the most severe environmental concerns. Furthermore, climate change and human impact are acting synergistically to alter the biogeochemical balance in aquatic ecosystems, thus promoting HABs large-scale expansion and greater toxin production with an increase in frequency and intensity all over the world. HABs are a symptom of stress in aquatic ecosystems and an emerging threat to aquatic wildlife, which can also compromise the availability of drinking water because toxins or other harmful effects of massive proliferation of microalgae can cause disease or death in humans and animals. Further, HABs alter ecosystem services, hampering human use of wetlands and resulting in great economic losses.

However, the cause of burst HABs and toxin production remains unknown, being one of the biggest gaps in the current limnological knowledge. Thus, new perspectives are needed to understand the ecological drivers of microalgal blooms and regulatory mechanisms of toxins, which will be the key scientific basis for risk assessment and the design of effective adaptation and management strategies of water resources, especially in the current context of global change.

Dr. Rafael Carballeira
Dr. Vitor Gonçalves
Guest Editors

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Keywords

  • harmful algae blooms (HABs)
  • microalgal toxins
  • cyanobacteria
  • red tides
  • ecosystem services
  • human health
  • reservoir management
  • wetland conservation

Published Papers (7 papers)

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Research

24 pages, 24628 KiB  
Article
An Unprecedented Bloom of Oceanic Dinoflagellates (Karenia spp.) Inside a Fjord within a Highly Dynamic Multifrontal Ecosystem in Chilean Patagonia
by Ángela M. Baldrich, Patricio A. Díaz, Sergio A. Rosales, Camilo Rodríguez-Villegas, Gonzalo Álvarez, Iván Pérez-Santos, Manuel Díaz, Camila Schwerter, Michael Araya and Beatriz Reguera
Toxins 2024, 16(2), 77; https://doi.org/10.3390/toxins16020077 - 02 Feb 2024
Viewed by 1228
Abstract
At the end of summer 2020, a moderate (~105 cells L−1) bloom of potential fish-killing Karenia spp. was detected in samples from a 24 h study focused on Dinophysis spp. in the outer reaches of the Pitipalena-Añihue Marine Protected Area. [...] Read more.
At the end of summer 2020, a moderate (~105 cells L−1) bloom of potential fish-killing Karenia spp. was detected in samples from a 24 h study focused on Dinophysis spp. in the outer reaches of the Pitipalena-Añihue Marine Protected Area. Previous Karenia events with devastating effects on caged salmon and the wild fauna of Chilean Patagonia had been restricted to offshore waters, eventually reaching the southern coasts of Chiloé Island through the channel connecting the Chiloé Inland Sea to the Pacific Ocean. This event occurred at the onset of the COVID-19 lockdown when monitoring activities were slackened. A few salmon mortalities were related to other fish-killing species (e.g., Margalefidinium polykrikoides). As in the major Karenia event in 1999, the austral summer of 2020 was characterised by negative anomalies in rainfall and river outflow and a severe drought in March. Karenia spp. appeared to have been advected in a warm (14–15 °C) surface layer of estuarine saline water (S > 21). A lack of daily vertical migration patterns and cells dispersed through the whole water column suggested a declining population. Satellite images confirmed the decline, but gave evidence of dynamic multifrontal patterns of temperature and chl a distribution. A conceptual circulation model is proposed to explain the hypothetical retention of the Karenia bloom by a coastally generated eddy coupled with the semidiurnal tides at the mouth of Pitipalena Fjord. Thermal fronts generated by (topographically induced) upwelling around the Tic Toc Seamount are proposed as hot spots for the accumulation of swimming dinoflagellates in summer in the southern Chiloé Inland Sea. The results here provide helpful information on the environmental conditions and water column structure favouring Karenia occurrence. Thermohaline properties in the surface layer in summer can be used to develop a risk index (positive if the EFW layer is thin or absent). Full article
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36 pages, 8285 KiB  
Article
Molecular Phylogeny, Morphology, Growth and Toxicity of Three Benthic Dinoflagellates Ostreopsis sp. 9, Prorocentrum lima and Coolia monotis Developing in Strait of Gibraltar, Southwestern Mediterranean
by Mustapha Ibghi, Benlahcen Rijal Leblad, Mohammed L’Bachir El Kbiach, Hicham Aboualaalaa, Mouna Daoudi, Estelle Masseret, Emilie Le Floc’h, Fabienne Hervé, Gwenael Bilien, Nicolas Chomerat, Zouher Amzil and Mohamed Laabir
Toxins 2024, 16(1), 49; https://doi.org/10.3390/toxins16010049 - 16 Jan 2024
Viewed by 1746
Abstract
Few works have been carried out on benthic harmful algal blooms (BHAB) species in the southern Mediterranean and no data are available for the highly dynamic Strait of Gibraltar (western Mediterranean waters). For the first time, Ostreopsis sp. 9, Prorocentrum lima and Coolia [...] Read more.
Few works have been carried out on benthic harmful algal blooms (BHAB) species in the southern Mediterranean and no data are available for the highly dynamic Strait of Gibraltar (western Mediterranean waters). For the first time, Ostreopsis sp. 9, Prorocentrum lima and Coolia monotis were isolated in this key region in terms of exchanges between the Atlantic Ocean and the Mediterranean and subject to intense maritime traffic. Ribotyping confirmed the morphological identification of these three dinoflagellates species. Monoclonal cultures were established and the maximum growth rate and cell yield were measured at a temperature of 24 °C and an irradiance of 90 µmol photons m−2 s−1, for each species: 0.26 ± 0.02 d−1 (8.75 × 103 cell mL−1 after 28 days) for Ostreopsis sp. 9, 0.21 ± 0.01 d−1 (49 × 103 cell mL−1 after 145 days) for P. lima and 0.21 ± 0.01 d−1 (10.02 × 103 cell mL−1 after 28 days) for C. monotis. Only P. lima was toxic with concentrations of okadaic acid and dinophysistoxin-1 measured in optimal growth conditions ranging from 6.4 pg cell−1 to 26.97 pg cell−1 and from 5.19 to 25.27 pg cell−1, respectively. The toxin content of this species varied in function of the growth phase. Temperature influenced the growth and toxin content of P. lima. Results suggest that future warming of Mediterranean coastal waters may lead to higher growth rates and to increases in cellular toxin levels in P. lima. Nitrate and ammonia affected the toxin content of P. lima but no clear trend was noted. In further studies, we have to isolate other BHAB species and strains from Strait of Gibraltar waters to obtain more insight into their diversity and toxicity. Full article
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14 pages, 11974 KiB  
Article
A Digital Twin Lake Framework for Monitoring and Management of Harmful Algal Blooms
by Yinguo Qiu, Hao Liu, Jiaxin Liu, Dexin Li, Chengzhao Liu, Weixin Liu, Jindi Wang and Yaqin Jiao
Toxins 2023, 15(11), 665; https://doi.org/10.3390/toxins15110665 - 17 Nov 2023
Cited by 1 | Viewed by 1370
Abstract
Harmful algal blooms (HABs) caused by lake eutrophication and climate change have become one of the most serious problems for the global water environment. Timely and comprehensive data on HABs are essential for their scientific management, a need unmet by traditional methods. This [...] Read more.
Harmful algal blooms (HABs) caused by lake eutrophication and climate change have become one of the most serious problems for the global water environment. Timely and comprehensive data on HABs are essential for their scientific management, a need unmet by traditional methods. This study constructed a novel digital twin lake framework (DTLF) aiming to integrate, represent and analyze multi-source monitoring data on HABs and water quality, so as to support the prevention and control of HABs. In this framework, different from traditional research, browser-based front ends were used to execute the video-based HAB monitoring process, and real-time monitoring in the real sense was realized. On this basis, multi-source monitored results of HABs and water quality were integrated and displayed in the constructed DTLF, and information on HABs and water quality can be grasped comprehensively, visualized realistically and analyzed precisely. Experimental results demonstrate the satisfying frequency of video-based HAB monitoring (once per second) and the valuable results of multi-source data integration and analysis for HAB management. This study demonstrated the high value of the constructed DTLF in accurate monitoring and scientific management of HABs in lakes. Full article
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13 pages, 1369 KiB  
Article
The Effect of Microcystis on the Monitoring of Faecal Indicator Bacteria
by Jingjing Zhou, Mingzhi Qu, Christy Dunkinson, Daniel D. Lefebvre, Yuxiang Wang and R. Stephen Brown
Toxins 2023, 15(11), 628; https://doi.org/10.3390/toxins15110628 - 26 Oct 2023
Viewed by 1286
Abstract
The survival of Escherichia coli (E. coli) bacteria, the most common faecal indicator bacteria (FIB), may be significantly affected by cyanobacteria present during a harmful algal bloom (HAB). Therefore, the effect of Microcystis on the survival of FIB E.coli and coliforms [...] Read more.
The survival of Escherichia coli (E. coli) bacteria, the most common faecal indicator bacteria (FIB), may be significantly affected by cyanobacteria present during a harmful algal bloom (HAB). Therefore, the effect of Microcystis on the survival of FIB E.coli and coliforms was investigated. Microcosms containing two species of Microcystis (M. aeruginosa and M. smithii) were established and then inoculated with four reference strains of E. coli (ATCC 25922, 8739, 51813, and 11775) to explore the cyanobacteria-bacteria dynamics at a laboratory setting. Monitoring over several days showed normal growth of Microcystis, with or without the presence of E. coli. However, Microcystis was shown to dramatically decrease the survival of E. coli over time. Analysis of microcystin production by Microcystis was found to correlate with loss of E. coli, suggesting a toxic effect of microcystins on E. coli bacteria. This phenomenon was also demonstrated for a natural consortium of E. coli and coliform bacteria by inoculating with contaminated lake water. The results indicate that the use of E. coli as FIB may be greatly compromised in the presence of Microcystis spp. such as during a HAB when associated toxins are produced. Full article
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17 pages, 2700 KiB  
Article
Application of a Quantitative PCR to Investigate the Distribution and Dynamics of Two Morphologically Similar Species, Karenia mikimotoi and K. papilionacea (Dinophyceae) in Korean Coastal Waters
by Sunju Kim, Minji Cho, Jiae Yoo and Bum Soo Park
Toxins 2023, 15(7), 469; https://doi.org/10.3390/toxins15070469 - 20 Jul 2023
Cited by 2 | Viewed by 1221
Abstract
Species of the marine dinoflagellate genus Karenia are known to produce various potent biotoxins and can form noxious blooms that cause mass mortalities of fish and shellfish. To date, harmful blooms of the species K. mikimotoi have been reported in Korea, but K. [...] Read more.
Species of the marine dinoflagellate genus Karenia are known to produce various potent biotoxins and can form noxious blooms that cause mass mortalities of fish and shellfish. To date, harmful blooms of the species K. mikimotoi have been reported in Korea, but K. papilionacea was recently recorded off the southern coast of Korea. Here, we developed a quantitative real-time PCR (qRT-PCR) assay with specific primer pairs for the accurate detection and quantification of these two similar-looking unarmored species, K. mikimotoi and K. papilionacea, and investigated their distribution and dynamics in Korean coastal waters. Overall, K. papilionacea had not only a wider distribution, but also higher cell abundances (15–2553 cells L−1) than K. mikimotoi (3–122 cells L−1) in surface waters. Of 18 sampling sites, the two Karenia species were found to coexist at two sites. During monitoring at a fixed station (S5), K. papilionacea was generally predominant over K. mikimotoi; however, the two species exhibited similar dynamics and occasionally co-occurred. Both Karenia species showed similar physiological responses to temperature and salinity, requiring similar conditions for optimum growth. These results suggest that blooms of the two species may co-occur and induce a synergistic adverse effect on marine environments. Full article
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12 pages, 5247 KiB  
Article
Oceanographical Context of the First Bloom of the Silicoflagellate Octactis speculum (Ehrenberg) Recorded to Cause Salmon Mortality in a Galician Ria: Was This Bloom a Rare Event in the Iberian Coast?
by Ricardo Prego, Rafael Carballeira, Yolanda Pazos and Roberto Bao
Toxins 2023, 15(7), 435; https://doi.org/10.3390/toxins15070435 - 02 Jul 2023
Cited by 1 | Viewed by 988
Abstract
Harmful algal blooms are one of the leading causes of mortality in salmon aquaculture, with significant economic consequences. From 15 to 31 October 1996, a bloom of the skeletonized form of Octactis speculum (Ehrenberg) F.H. Chang, J.M. Grieve & J.E. Sutherland was detected [...] Read more.
Harmful algal blooms are one of the leading causes of mortality in salmon aquaculture, with significant economic consequences. From 15 to 31 October 1996, a bloom of the skeletonized form of Octactis speculum (Ehrenberg) F.H. Chang, J.M. Grieve & J.E. Sutherland was detected in the small Merexo inlet (1.7 km2 area), located on the southern shore of the Ria of Muxía (Galicia, NW Spain). The O. speculum population inside the inlet (data period: 1992–1996) seldom exceeded 4·103 cell·L−1. However, its concentration reached 2·105 cell·L−1 during the bloom, coinciding with a decrease in light penetration from 5 to 2 m deep, as measured using a Secchi disk. Although similar concentrations were reported during late October 1992, this was the first time that a bloom was associated with caged salmon (Salmo salar, Linnaeus 1758) mortality in the Galician coastal waters. This mortality was not associated with anoxia in the water column, but with fish gill irritations and mucus segregation due to gill clogging. Excess nitrate and silicate, the latter being essential for skeleton formation, were measured in the inlet during the bloom, with phosphate acting as the limiting nutrient (high negative correlation). Blooms of O. speculum occurred in autumn–winter, when water was retained within the inlet under meteorological conditions of southwest winds (which prompted downwelling conditions) and clear skies. A review of the oceanographic database of the Galician rias showed that massive O. speculum proliferations are also commonplace in other rias with similar environmental conditions, such as the Ria of Ares-Betanzos, and can therefore constitute a threat for the development of salmon aquaculture on this coast. Full article
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19 pages, 3856 KiB  
Article
Dissolved Algal Toxins along the Southern Coast of British Columbia Canada
by Ryan B. Shartau, Lenora D. M. Turcotte, Julia C. Bradshaw, Andrew R. S. Ross, Blair D. Surridge, Nina Nemcek and Stewart C. Johnson
Toxins 2023, 15(6), 395; https://doi.org/10.3390/toxins15060395 - 13 Jun 2023
Cited by 1 | Viewed by 1675
Abstract
Harmful algal blooms (HABs) in coastal British Columbia (BC), Canada, negatively impact the salmon aquaculture industry. One disease of interest to salmon aquaculture is Net Pen Liver Disease (NPLD), which induces severe liver damage and is believed to be caused by the exposure [...] Read more.
Harmful algal blooms (HABs) in coastal British Columbia (BC), Canada, negatively impact the salmon aquaculture industry. One disease of interest to salmon aquaculture is Net Pen Liver Disease (NPLD), which induces severe liver damage and is believed to be caused by the exposure to microcystins (MCs). To address the lack of information about algal toxins in BC marine environments and the risk they pose, this study investigated the presence of MCs and other toxins at aquaculture sites. Sampling was carried out using discrete water samples and Solid Phase Adsorption Toxin Tracking (SPATT) samplers from 2017–2019. All 283 SPATT samples and all 81 water samples tested positive for MCs. Testing for okadaic acid (OA) and domoic acid (DA) occurred in 66 and 43 samples, respectively, and all samples were positive for the toxin tested. Testing for dinophysistoxin-1 (DTX-1) (20 samples), pectenotoxin-2 (PTX-2) (20 samples), and yessotoxin (YTX) (17 samples) revealed that all samples were positive for the tested toxins. This study revealed the presence of multiple co-occurring toxins in BC’s coastal waters and the levels detected in this study were below the regulatory limits for health and recreational use. This study expands our limited knowledge of algal toxins in coastal BC and shows that further studies are needed to understand the risks they pose to marine fisheries and ecosystems. Full article
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