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8. Fish Kills Related to Harmful Algal Bloom Events in Southeast Asia.

Author

San Diego-McGlone, Maria Lourdes, Yñiguez, Aletta T., Benico, Garry, Lum, Wai Mun, Hii, Kieng Soon, Leong, Sandric Chee Yew, Leaw, Chui Pin, Iwataki, Mitsunori, and Lim, Po Teen

Abstract

Fish kills in Southeast Asia are frequently associated with harmful algal blooms (HABs) and cause significant ecological and economic impacts and can have negative effects on the sustainability of aquatic ecosystems and the fisheries they support. This paper serves as a review of fish-kill events with focus on those related to HABs within the region. It examines the causative algal species, known mechanisms of fish mortality, and socio-economic consequences in order to better understand and manage this threat to sustainable fisheries. Fish kills have been reported across multiple countries within Southeast Asia, with notable hotspots in the Philippines, Malaysia, Singapore, Indonesia, and Thailand. The common harmful microalgal species span a diverse group including dinoflagellates (Karenia spp., Karlodinium spp., Margalefidinium polykrikoides, Noctiluca scintillans), raphidophytes (Chattonella spp.), diatoms (Skeletonema spp. and Chaetoceros spp.), and cyanobacteria (Trichodesmium spp.). These microalgae lead to fish kills through mechanisms such as hypoxia, physical gill damage, and ichthyotoxin production. Freshwater fish kills linked to HABs have also been documented for the Philippines, but there is no or limited information for the region. Our review highlights the widespread and recurring nature of fish kills, their impact on fisheries and aquaculture, and challenges in managing and mitigating their effects. There are efforts at enhancing management and mitigation using clay and early warning systems. However, it is essential to further improve monitoring efforts, the development and deployment of early warning systems, and viable and holistic mitigation strategies to protect the region's aquatic resources and dependent communities, especially as aquaculture and coastal development are increasing concurrent with a changing climate that can exacerbate the risks of fish kills and HABs in Southeast Asia. [ABSTRACT FROM AUTHOR]

Published
2024
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13. The harmful raphidophyte Chattonella (Raphidophyceae) in Western Pacific: Its red tides and associated fisheries damage over the past 50 years (1969–2019)

Author

Lum, Wai Mun, Benico, Garry, Doan-Nhu, Hai, Furio, Elsa, Leaw, Chui Pin, Leong, Sandric Chee Yew, Lim, Po Teen, Lim, Weol Ae, Lirdwitayaprasit, Thaithaworn, Lu, Songhui, Muawanah, Nguyen, Nguyen Van, Orlova, Tatiana Yu., Rachman, Arief, Sakamoto, Setsuko, Takahashi, Kazuya, Teng, Sing Tung, Thoha, Hikmah, Wang, Pengbin, Yñiguez, Aletta T., Wakita, Kazumi, and Iwataki, Mitsunori

Published
2021
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16. First report of toxigenic Amphidoma languida (Amphidomataceae, Dinophyceae) from the Pacific, with reference to intracellular ultrastructure and azaspiracid compounds.

Author

Kuwata, Koyo, Hernández‐Becerril, David U., Ozawa, Mayu, Uchida, Hajime, Lum, Wai Mun, Takahashi, Kazuya, Benico, Garry, Suzuki, Toshiyuki, and Iwataki, Mitsunori

Subjects
TRANSMISSION electron microscopy, PARIETAL cells, SCANNING electron microscopy, MASS spectrometry, CHLOROPLASTS
Abstract

SUMMARY: Morphology, phylogeny and azaspiracid (AZA) production of a strain of Amphidoma languida isolated from the subtropical Mexican Pacific were examined. Scanning electron microscopy showed the thecal plate arrangement of Am. languida from Mexico as Po, cp, X, 6′, 6′′, 6C, 5S, 6′′′, 2′′′′, with the prominent apical pore complex, the ventral pore on the anterior of the 1′ plate near the suture to the 6′ plate, and the antapical pore on the 2′′′′ plate, which are congruent with those of Am. languida reported from the Atlantic. The ventral depression was occasionally observed on the anterior end of Sa plate. Cells had a dinokaryotic nucleus positioned in the posterior part of the cell and parietal yellowish chloroplasts with a spherical pyrenoid in the episome. Transmission electron microscopy showed crystalline vesicles and tubular cytoplasmic invaginations in the pyrenoid, which resembled those reported from the most related non‐toxigenic species Amphidoma fulgens. The intracellular components, different from Am. fulgens, were oil droplets and lipid‐associated membranous structures. AZA‐2 was detected from the strain by liquid chromatography‐tandem mass spectrometry with a cell quota of 30.9 fg cell−1. Three other AZA‐related compounds were also detected. This is the first report of AZA‐producing Am. languida in the Pacific Ocean. [ABSTRACT FROM AUTHOR]

Published
2024
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17. Morphological and phylogenetic data do not support the split of Alexandrium into four genera

Author

Mertens, Kenneth Neil, Adachi, Masao, Anderson, Donald M., Band-Schmidt, Christine J., Bravo, Isabel, Brosnahan, Michael L., Bolch, Christopher J.S., Calado, António J., Carbonell-Moore, M. Consuelo, Chomérat, Nicolas, Elbrächter, Malte, Figueroa, Rosa Isabel, Fraga, Santiago, Gárate-Lizárraga, Ismael, Garcés, Esther, Gu, Haifeng, Hallegraeff, Gustaaf, Hess, Philipp, Hoppenrath, Mona, Horiguchi, Takeo, Iwataki, Mitsunori, John, Uwe, Kremp, Anke, Larsen, Jacob, Leaw, Chui Pin, Li, Zhun, Lim, Po Teen, Litaker, Wayne, MacKenzie, Lincoln, Masseret, Estelle, Matsuoka, Kazumi, Moestrup, Øjvind, Montresor, Marina, Nagai, Satoshi, Nézan, Elisabeth, Nishimura, Tomohiro, Okolodkov, Yuri B., Orlova, Tatiana Yu., Reñé, Albert, Sampedro, Nagore, Satta, Cecilia Teodora, Shin, Hyeon Ho, Siano, Raffaele, Smith, Kirsty F., Steidinger, Karen, Takano, Yoshihito, Tillmann, Urban, Wolny, Jennifer, Yamaguchi, Aika, and Murray, Shauna

Published
2020
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19. Perceived global increase in algal blooms is attributable to intensified monitoring and emerging bloom impacts

Author

Hallegraeff, Gustaaf M., Anderson, Donald M., Belin, Catherine, Bottein, Marie-Yasmine Dechraoui, Bresnan, Eileen, Chinain, Mireille, Enevoldsen, Henrik, Iwataki, Mitsunori, Karlson, Bengt, McKenzie, Cynthia H., Sunesen, Inés, Pitcher, Grant C., Provoost, Pieter, Richardson, Anthony, Schweibold, Laura, Tester, Patricia A., Trainer, Vera L., Yñiguez, Aletta T., and Zingone, Adriana

Published
2021
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23. Overview of Harmful Algal Blooms in Asia

Author

Furuya, Ken, Iwataki, Mitsunori, Lim, Po Teen, Lu, Songhui, Leaw, Chui-Pin, Azanza, Rhodora V., Kim, Hak-Gyoon, Fukuyo, Yasuwo, Caldwell, Martyn M., Series Editor, Díaz, Sandra, Series Editor, Heldmaier, Gerhard, Series Editor, Jackson, Robert B., Series Editor, Lange, Otto L., Series Editor, Levia, Delphis F., Series Editor, Mooney, Harold A., Series Editor, Schulze, Ernst-Detlef, Series Editor, Sommer, Ulrich, Series Editor, Glibert, Patricia M., editor, Berdalet, Elisa, editor, Burford, Michele A., editor, Pitcher, Grant C., editor, and Zhou, Mingjiang, editor

Published
2018
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25. A new small thecate dinoflagellate Azadinium anteroporum sp. nov. (Amphidomataceae, Dinophyceae) isolated from the Asian Pacific

Author

Kuwata, Koyo, primary, Lum, Wai Mun, additional, Takahashi, Kazuya, additional, Benico, Garry, additional, Uchida, Hajime, additional, Ozawa, Mayu, additional, Matsushima, Ryoji, additional, Watanabe, Ryuichi, additional, Oikawa, Hiroshi, additional, Suzuki, Toshiyuki, additional, and Iwataki, Mitsunori, additional

Published
2023
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26. Comparative effects of temperature and salinity on growth of four harmful Chattonella spp. (Raphidophyceae) from tropical Asian waters

Author

Lum, Wai Mun, primary, Sakamoto, Setsuko, additional, Yuasa, Koki, additional, Takahashi, Kazuya, additional, Kuwata, Koyo, additional, Kodama, Taketoshi, additional, Katayama, Tomoyo, additional, Leaw, Chui Pin, additional, Lim, Po Teen, additional, Takahashi, Kazutaka, additional, and Iwataki, Mitsunori, additional

Published
2023
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28. Harmful Algae in Indonesia: Small in Size, Big in Effect

Author

Muawanah, Bayu Intan, Mariana D., Boudin, Elyse, Thoha, Hikmah, Rachman, Arief, Sianturi, Oksto Ridho, Sidabutar, Tumpak, Iwataki, Mitsunori, Takahashi, Kazuya, Avarre, Jean-christophe, Carcaillet, Frédérique, Masseret, Estelle, Muawanah, Bayu Intan, Mariana D., Boudin, Elyse, Thoha, Hikmah, Rachman, Arief, Sianturi, Oksto Ridho, Sidabutar, Tumpak, Iwataki, Mitsunori, Takahashi, Kazuya, Avarre, Jean-christophe, Carcaillet, Frédérique, and Masseret, Estelle

Abstract

Sometimes the waters of seas, rivers, or lakes turn an odd color, becoming brown, red, or green. These colors are actually those of tiny algae that are invisible to the naked eye—but those algae are reproducing so fast that they stain the water. These events are called algal blooms, and they can be harmful because they produce toxins that kill aquatic animals and can cause poisoning in humans. Our group investigated the harmful algal blooms that have been occurring regularly in Lampung Bay, Indonesia, since 2012. We tracked down the algal species responsible for these blooms by analyzing seawater and the seabed sediments of the bay. We identified one species of algae, a dinoflagellate called Margalefidinium polykrikoides, as the culprit. This species can take on multiple shapes, which makes its identification particularly difficult. Improving our knowledge about this algal species will eventually help us understand what triggers harmful algal blooms and how to prevent them.

Published
2023
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29. FISH-KILLING MARINE ALGAL BLOOMS:Causative Organisms, Ichthyotoxic Mechanisms, Impacts and Mitigation

Author

Hallegraeff, Gustaaf, Anderson, Donald M., Davidson, Keith, Gianella , Facchin, Hansen, Per Juel, Iwataki, Mitsunori, Larsen, Thomas Ostenfeld, Hegaret, Hélène, Mardones, Jorge I., MacKenzie, Lincoln, Rensel, J. E., Hallegraeff, Gustaaf, Anderson, Donald M., Davidson, Keith, Gianella , Facchin, Hansen, Per Juel, Iwataki, Mitsunori, Larsen, Thomas Ostenfeld, Hegaret, Hélène, Mardones, Jorge I., MacKenzie, Lincoln, and Rensel, J. E.

Abstract

Fish-killing microalgal blooms are responsible for much greater global socio-economic impacts than the well-studied HAB species causing seafood biotoxin contamination. Examples are the 1972 Chattonella marina bloom in the Seto Inland Sea, Japan (estimated USD 71M loss to yellowtail aquaculture), the 1988 Prymnesium polylepis bloom in the European Kattegat with broad marine ecosystem impacts, and the 2015/16 Pseudochattonella verruculosa bloom in Chile (USD 800M loss to salmon aquaculture). Highly potent fish-killers include the globally distributed, taxonomically unrelated dinoflagellate genera Alexandrium, Karenia, Karlodinium and Margalefidinium, raphidophytes Chattonella and Heterosigma, dictyochophytes Pseudochattonella and Vicicitus, and haptophytes Chrysochromulina and Prymnesium. All these species have in common their propensity to produce lytic compounds that irreparably damage the sensitive gill tissues of fish which ultimately die from suffocation. Except for recent advances with Karlodinium (karlotoxins), Prymnesium (prymnesins), and Karenia brevisulcata (brevisulcenals), the precise mechanisms of how such microalgae kill finfish remain poorly understood. Reactive Oxygen Species can be a co-factor in ichthyotoxicity, notably with raphidophytes such as Chattonella. While some species are always ichthyotoxic, others such as Heterosigma, Pseudochattonella and Alexandrium catenella kill fish only under certain conditions or life stages. Broad scale ecosystem impacts from fish killing algae are less common with raphidophytes and dictyochophytes that require intimate cellular contact for harmful effects, compared to Karenia and Prymnesium where intracellular or excreted toxins are responsible. Critical hurdles that limit progress in our understanding of ichthyotoxins and their control and mitigation include: HABs at fish farms are not usually a research priority until a major bloom occurs; data sharing between industry and scientists is very limited; an

Published
2023

31. New Azaspiracid Analogues Detected as Bi-Charged Ions in Azadinium Poporum (Amphidomataceae, Dinophyceae) Isolated from Japanese Coastal Waters

Author

Ozawa, Mayu, primary, Uchida, Hajime, additional, Watanabe, Ryuichi, additional, Numano, Satoshi, additional, Matsushima, Ryoji, additional, Oikawa, Hiroshi, additional, Takahashi, Kazuya, additional, Lum, Wai Mun, additional, Benico, Garry, additional, Iwataki, Mitsunori, additional, and Suzuki, Toshiyuki, additional

Published
2023
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35. Ultrastructure and Systematics of Two New Species of Dinoflagellate, Paragymnodinium Asymmetricum sp. nov. and Paragymnodinium Inerme sp. nov. (Gymnodiniales, Dinophyceae)(1)

Author

Yokouchi, Koh, Takahashi, Kazuya, Nguyen, Van Nguyen, Iwataki, Mitsunori, and Horiguchi, Takeo

Subjects
taxonomy, nutritional mode, chloroplast, nematocyst, Gymnodinium sensu stricto, flagellar apparatus, Paragymnodinium
Abstract

The genus Paragymnodinium currently includes two species, P. shiwhaense and P. stigmaticum, that are characterized by mixotrophic nutrition and the possession of nematocysts. In this study, two new dinoflagellates belonging to this genus were described based on observations using LM, SEM, and TEM together with a molecular analysis. Cells of P. asymmetricum sp. nov., isolated from Nha Trang Beach, Vietnam, were 7.9-12.6 mu m long and 4.7-9.0 mu m wide. The species showed no evidence of feeding behavior and was able to sustain itself phototrophically. Paragymnodinium asymmetricum shared many features with P. shiwhaense, including presence of nematocysts, absence of an eyespot, and a planktonic lifestyle, but was clearly distinguished by the asymmetric shape of the hyposome, possession of a single chloroplast, and its nutritional mode. Cells of P. inerme sp. nov., isolated from Jogashima, Kanagawa Pref, Japan, were 15.3-23.7 mu m long and 10.9-19.6 mu m wide. This species also showed no evidence of feeding behavior. Paragymnodinium inerme was similar to cells of P. shiwhaense in shape and planktonic lifestyle, but its nutritional mode was different. The presence of incomplete nematocysts was also a unique feature. A phylogenetic analysis inferred from concatenated SSU and LSU rDNA sequences recovered the two dinoflagellates in a robust clade with Paragymnodinium spp., within the clade of Gymnodinium sensu stricto. This evidence, together with their morphological similarities, made it reasonable to conclude that these two dinoflagellates are new species of Paragymnodinium.

Published
2020

39. Morphological variation and phylogeny ofKarenia selliformis(Gymnodiniales, Dinophyceae) in an intensive cold-water algal bloom in eastern Hokkaido, Japan in September–November 2021

Author

Iwataki, Mitsunori, primary, Lum, Wai Mun, additional, Kuwata, Koyo, additional, Takahashi, Kazuya, additional, Arima, Daichi, additional, Kuribayashi, Takanori, additional, Kosaka, Yuki, additional, Hasegawa, Natsuki, additional, Watanabe, Tsuyoshi, additional, Shikata, Tomoyuki, additional, Isada, Tomonori, additional, Orlova, Tatiana Yu., additional, and Sakamoto, Setsuko, additional

Published
2021
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46. Toxigenic strains of Azadinium poporum (Amphidomataceae, Dinophyceae) from Japan and Vietnam, with first reports of A. poporum (ribotype A) and A. trinitatum in Asian Pacific

Author

Takahashi, Kazuya, primary, Lum, Wai Mun, additional, Benico, Garry, additional, Uchida, Hajime, additional, Ozawa, Mayu, additional, Oikawa, Hiroshi, additional, Suzuki, Toshiyuki, additional, Nguyen, Nguyen Van, additional, Ha, Dao Viet, additional, and Iwataki, Mitsunori, additional

Published
2021
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50. Morphological and phylogenetic data do not support the split of Alexandrium into four genera

Author

Mertens, Kenneth, Adachi, Masao, Anderson, Donald M., Band-schmidt, Christine J., Bravo, Isabel, Brosnahan, Michael L., Bolch, Christopher J.s., Calado, António J., Carbonell-moore, M. Consuelo, Chomérat, Nicolas, Elbrächter, Malte, Figueroa, Rosa Isabel, Fraga, Santiago, Gárate-lizárraga, Ismael, Garcés, Esther, Gu, Haifeng, Hallegraeff, Gustaaf, Hess, Philipp, Hoppenrath, Mona, Horiguchi, Takeo, Iwataki, Mitsunori, John, Uwe, Kremp, Anke, Larsen, Jacob, Leaw, Chui Pin, Li, Zhun, Lim, Po Teen, Litaker, Wayne, Mackenzie, Lincoln, Masseret, Estelle, Matsuoka, Kazumi, Moestrup, Øjvind, Montresor, Marina, Nagai, Satoshi, Nézan, Elisabeth, Nishimura, Tomohiro, Okolodkov, Yuri B., Orlova, Tatiana Yu., Reñé, Albert, Sampedro, Nagore, Satta, Cecilia Teodora, Shin, Hyeon Ho, Siano, Raffaele, Smith, Kirsty F., Steidinger, Karen, Takano, Yoshihito, Tillmann, Urban, Wolny, Jennifer, Yamaguchi, Aika, Murray, Shauna, Mertens, Kenneth, Adachi, Masao, Anderson, Donald M., Band-schmidt, Christine J., Bravo, Isabel, Brosnahan, Michael L., Bolch, Christopher J.s., Calado, António J., Carbonell-moore, M. Consuelo, Chomérat, Nicolas, Elbrächter, Malte, Figueroa, Rosa Isabel, Fraga, Santiago, Gárate-lizárraga, Ismael, Garcés, Esther, Gu, Haifeng, Hallegraeff, Gustaaf, Hess, Philipp, Hoppenrath, Mona, Horiguchi, Takeo, Iwataki, Mitsunori, John, Uwe, Kremp, Anke, Larsen, Jacob, Leaw, Chui Pin, Li, Zhun, Lim, Po Teen, Litaker, Wayne, Mackenzie, Lincoln, Masseret, Estelle, Matsuoka, Kazumi, Moestrup, Øjvind, Montresor, Marina, Nagai, Satoshi, Nézan, Elisabeth, Nishimura, Tomohiro, Okolodkov, Yuri B., Orlova, Tatiana Yu., Reñé, Albert, Sampedro, Nagore, Satta, Cecilia Teodora, Shin, Hyeon Ho, Siano, Raffaele, Smith, Kirsty F., Steidinger, Karen, Takano, Yoshihito, Tillmann, Urban, Wolny, Jennifer, Yamaguchi, Aika, and Murray, Shauna

Abstract

A recently published study analyzed the phylogenetic relationship between the genera Centrodinium and Alexandrium, confirming an earlier publication showing the genus Alexandrium as paraphyletic. This most recent manuscript retained the genus Alexandrium, introduced a new genus Episemicolon, resurrected two genera, Gessnerium and Protogonyaulax, and stated that: “The polyphyly [sic] of Alexandrium is solved with the split into four genera”. However, these reintroduced taxa were not based on monophyletic groups. Therefore this work, if accepted, would result in replacing a single paraphyletic taxon with several non-monophyletic ones. The morphological data presented for genus characterization also do not convincingly support taxa delimitations. The combination of weak molecular phylogenetics and the lack of diagnostic traits (i.e., autapomorphies) render the applicability of the concept of limited use. The proposal to split the genus Alexandrium on the basis of our current knowledge is rejected herein. The aim here is not to present an alternative analysis and revision, but to maintain Alexandrium. A better constructed and more phylogenetically accurate revision can and should wait until more complete evidence becomes available and there is a strong reason to revise the genus Alexandrium. The reasons are explained in detail by a review of the available molecular and morphological data for species of the genera Alexandrium and Centrodinium. In addition, cyst morphology and chemotaxonomy are discussed, and the need for integrative taxonomy is highlighted.

Published
2020
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