Article
Environmental Sciences
Hyeon Ho Shin, Moon Ho Son, Bum Soo Park, Kyung Ha Han, Joo Yeon Youn, Kyeong Yoon Kwak, Ji Hoon Lee, A. -Young Shin, Eunjung Byun, Yeong Du Yoo, Min Ho Seo, Kyungsoon Shin, Zhun Li
Summary: This study investigated the germination features of ellipsoidal Alexandrium cysts isolated from sediments collected in Jinhae-Masan Bay, Korea. The results showed that the cysts could germinate across a wide range of temperature and their germination was not controlled by seasonal salinity changes. These findings provide important insights into the bloom dynamics of Alexandrium catenella in Jinhae-Masan Bay.
MARINE POLLUTION BULLETIN
(2023)
Article
Environmental Sciences
Camilo Rodriguez-Villegas, Rosa Figueroa, Ivan Perez-Santos, Carlos Molinet, Gonzalo S. Saldias, Sergio A. Rosales, Gonzalo Alvarez, Pamela Linford, Patricio A. Diaz
Summary: Harmful Algal Blooms (HAB) are a significant global issue, with the dinoflagellate species Alexandrium catenella being responsible for the toxin named Paralytic Shellfish Poisoning (PSP). Understanding the origins and formation of these blooms is essential for prediction. Previous research in Chilean Patagonia has focused on coastal areas, neglecting the adjacent oceanic regions. Through a combination of field studies and modeling approaches, it was found that the submarine canyons in the continental shelf off northern Chilean Patagonia enhance coastal upwelling, increasing the risk of resuspension of A. catenella resting cysts.
MARINE POLLUTION BULLETIN
(2022)
Article
Marine & Freshwater Biology
Ying Zhong Tang, Haifeng Gu, Zhaohui Wang, Dongyan Liu, Yan Wang, Douding Lu, Zhangxi Hu, Yunyan Deng, Lixia Shang, Yuzao Qi
Summary: Over the past three decades, studies in China have made significant progress in the research of dinoflagellates and other groups' resting cysts, including detecting species diversity, toxin production mechanism, and distribution, providing important references for the protection and management of coastal ecosystems.
Article
Marine & Freshwater Biology
Guat Ru Liow, Winnie Lik Sing Lau, Ing Kuo Law, Haifeng Gu, Chui Pin Leaw, Po Teen Lim
Summary: This study investigated the sexual reproduction of a toxigenic A. minutum in a laboratory setting, confirming its heterothallic nature and complex mating system with at least four distinct mating groups observed. Resting cysts were successfully produced in 41 out of 91 pairwise combinations of cross-mating strains, with a relatively shorter dormancy period of 5-8 days. The rapid encystment-excystment processes and short cyst dormancy period of this tropical Pacific A. minutum are believed to play crucial roles in governing bloom dynamics in the tropical coastal region.
PHYCOLOGICAL RESEARCH
(2021)
Review
Environmental Sciences
David W. Crawford, Paulina Montero, Giovanni Daneri
Summary: Evidences of shellfish toxicity have been recorded in South America since the late 16th Century. Toxic blooms of dinoflagellate Alexandrium catenella were first described in western Magellan Strait in the early 1970s and have since spread northward to Chilean Patagonia, culminating in a catastrophic event around Chiloé Island in 2016. Human activities may play a role in intensifying these blooms in more densely populated areas of northern Patagonia, while coastal areas with sparse human population density are less likely influenced
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Limnology
Wenjiao Tang, Huixia Geng, Yanjuan Xi, Qingchun Zhang, Xuexi Tang, Rencheng Yu
Summary: This study mapped the distribution of Alexandrium catenella resting cysts along the coast of Qinhuangdao through three surveys, and found a significant correlation between the abundance of resting cysts and vegetative cells, highlighting the important role of resting cysts in the bloom dynamics.
JOURNAL OF OCEANOLOGY AND LIMNOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Kyoko Yarimizu, Jorge Mardones, Javier Paredes-Mella, Luis Norambuena-Subiabre, Carl J. Carrano, Fumito Maruyama
Summary: This study investigated how iron conditions affect the growth and toxin production of A. catenella isolated from southern Chile, finding that optimal iron concentration is crucial for growth, while excess or insufficient iron can impact growth and toxin production.
Article
Marine & Freshwater Biology
Masumi Kamata, Naohisa Wada, Nina Yasuda, Daniel Varela, Jorge I. Mardones, Javier Paredes-Mella, Satoshi Nagai
Summary: The toxic dinoflagellate A. catenella poses a threat to seafood security in Chile. Genetic markers were developed to study its spatial and temporal diversity and genetic connectivity.
PLANKTON & BENTHOS RESEARCH
(2023)
Article
Marine & Freshwater Biology
Gustaaf M. Hallegraeff, Laura Schweibold, Enora Jaffrezic, Lesley Rhodes, Lincoln MacKenzie, Brenda Hay, Hazel Farrell
Summary: Australia and New Zealand both have similarities and differences in terms of harmful algal species occurrences and their impacts on human society, such as toxic shellfish toxin production. While both countries have experienced harmful algal events, the predominant seafood toxin syndromes differ between Australia and New Zealand.
Article
Biology
Marius N. Mueller, Frederico P. Brandini, Thomas W. Trull, Gustaaf M. Hallegraeff
Summary: The study found that environmental factors such as temperature, irradiance, carbonate chemistry, and macronutrient limitation significantly affect the coccosphere, coccolith, and cell volume of the Southern Ocean Emiliania huxleyi ecotype A. There is a strong correlation between cell and coccolith volume, indicating that coccolith volume is primarily controlled by physiological changes in cell volume. Macronutrient limitation, particularly of phosphorus and nitrogen, has the greatest influence on coccolith volume compared to other environmental drivers.
Article
Marine & Freshwater Biology
Alison Turnbull, Navreet Malhi, Andreas Seger, Jessica Jolley, Gustaaf Hallegraeff, Quinn Fitzgibbon
Summary: The study found that Southern Rock Lobsters exposed to and accumulating shellfish toxins in a controlled aquaculture setting did not show significant impacts on behavior, health, and nutrition; however, certain hematolymph biochemistry parameters showed changes indicating stress response.
AQUATIC TOXICOLOGY
(2021)
Article
Biodiversity Conservation
James Bramich, Christopher J. S. Bolch, Andrew Fischer
Summary: This study validates an improved version of a semi-analytical chl-a retrieval algorithm using Sentinel 2 platform, which includes a red-edge band at 704 nm and offers higher spatial resolution than other satellite platforms. By replacing a fixed chl-a specific absorption coefficient with a variable model, the algorithm achieved better performance in predicting chl-a concentrations, demonstrating a significant reduction in error and bias compared to the default algorithm.
ECOLOGICAL INDICATORS
(2021)
Editorial Material
Marine & Freshwater Biology
Gustaaf Hallegraeff, Henrik Enevoldsen, Adriana Zingone
Summary: The special issue presents a diverse picture of harmful algal bloom types and their socio-economic impacts at regional and subregional scale. The intensity and frequency of HAB events vary among regions, with some areas managing to control adverse effects on human health through increased monitoring activities, while risks to human activities and economic activities continue to exist.
Article
Multidisciplinary Sciences
L. Armbrecht, G. Hallegraeff, C. J. S. Bolch, C. Woodward, A. Cooper
Summary: By using hybridisation capture techniques and bioinformatic tools, we successfully increased the relative abundance of marine eukaryote sedaDNA and established a new proxy for evaluating its authenticity. This approach opens up new avenues for studying the long-term changes and evolution of marine eukaryotes over geological timescales.
SCIENTIFIC REPORTS
(2021)
Article
Biochemistry & Molecular Biology
Kyoko Yarimizu, Jorge Mardones, Javier Paredes-Mella, Luis Norambuena-Subiabre, Carl J. Carrano, Fumito Maruyama
Summary: This study investigated how iron conditions affect the growth and toxin production of A. catenella isolated from southern Chile, finding that optimal iron concentration is crucial for growth, while excess or insufficient iron can impact growth and toxin production.
Article
Food Science & Technology
Ana Flores-Lenero, Valentina Vargas-Torres, Javier Paredes-Mella, Luis Norambuena, Gonzalo Fuenzalida, Kim Lee-Chang, Jorge Mardones
Summary: This study confirms the occurrence of Heterosigma akashiwo in Chilean waters and provides insights into its growth conditions and cell characteristics. The findings suggest that the high production of long-chain PUFA and high ROS production may contribute to salmon mortality during H. akashiwo bloom events.
Review
Plant Sciences
Gustaaf M. Hallegraeff, Ruth S. Eriksen, Claire H. Davies, Julian Uribe-Palomino
Summary: This study reviewed 64 species of marine planktonic dinoflagellates from the Australian waters, confirming several causative organisms of diarrhetic shellfish poisoning. The ornate tropical genera Ornithocercus and Histioneis serve as warm-water indicators, while D. truncata is a cold-water Subantarctic species.
AUSTRALIAN SYSTEMATIC BOTANY
(2022)
Article
Plant Sciences
Luis Castro-Cera, Dario Vega-Diaz, Ruth S. Eriksen, Karine Leblanc, Gustaaf M. Hallegraeff
Summary: We reported the findings of the circumtropical dinoflagellate Tripos lanceolatus (Kofoid) F. Gomez from the Colombian Caribbean, with new records from the tropical western Pacific off Tonga and the Australian sector of the Indian Ocean. Scanning electron micrographs showed its morphological similarities to T. furca (Ehrenberg) F. Gomez within the subgenus Biceratium. Additionally, we reported the widely distributed tropical species T. schroeteri (B. Schroder) F. Gomez from the Colombian Caribbean and compared it to T. digitatus (F. Schutt) F. Gomez within the subgenus Archaeceratium.
Article
Fisheries
Muhamad Amin, Mark B. B. Adams, Christopher M. M. Burke, Christopher J. S. Bolch
Summary: Three strains of lactic acid bacteria (LAB) isolated from the gastrointestinal tract (GIT) of aquatic animals showed anti-Yersinia activity, indicating their potential as probiotics for the prevention of yersiniosis in Atlantic salmon. These strains, identified as Enterococcus sp., Enterococcus thailandicus, and Enterococcus durans, exhibited higher adhesion to salmon intestinal mucus compared to Y. ruckeri. Further in-vivo studies are needed to confirm the efficacy of these LAB in reducing the incidence of yersiniosis in salmonids.
JOURNAL OF FISH DISEASES
(2023)
Article
Paleontology
Bradley Paine, Linda Armbrecht, Christopher Bolch, Gustaaf M. Hallegraeff
Summary: Predicting phytoplankton responses to climate change in Tasmania's east coast requires a better understanding of longer-term variations from geological records. This study investigated coccolithophores in southeast Australian waters using microscopy and sedimentary ancient DNA techniques, revealing shifts in species dominance and periods of community instability. The findings provide valuable insights into the future of southeast Australian waters and underline the importance of coccolithophores in the marine ecosystem.
MARINE MICROPALEONTOLOGY
(2023)
Article
Biodiversity Conservation
Gustaaf M. M. Hallegraeff, Karine Leblanc
Summary: Antarctic diatom populations, such as Asteromphalus hookeri, A. hyalinus and A. parvulus, exhibit a wide range of hyaline rays. Different combinations of hyaline rays are observed in these diatoms, with 4 + 1 and 5 + 1 rays being the most common. Observations suggest that the separating lines in Asteromphalus play a crucial role in silica cell wall development. The taxonomy of two closely related diatom taxa, A. darwinii and A. hookeri, is discussed and their synonyms are listed.
