Resting cysts of Alexandrium catenella and A. pacificum (Dinophyceae) in the Bohai and Yellow Seas, China: Abundance, distribution and implications for toxic algal blooms

Dai, Lei; Yu, Rencheng; Geng, Hui-Xia; Zhao, Yue; Zhang, Qing‐Chun; Kong, Fan‐Zhou; Chen, Zhen-Fan; Zhao, Jiayu; Zhou, Mingjiang

doi:10.1016/j.hal.2020.101794

Cited by 23 publications

(5 citation statements)

References 44 publications

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“…To the best of our knowledge, this is the first report of the toxin profiles of A. pacificum from northern China, although this species is known to be present in the Bohai Sea and Yellow Sea of China [7,59]. One of these strains produced predominantly GTX1/4 but lacked C toxins.…”

Section: Identifying Populations Based On Physiological Differentiationmentioning

confidence: 82%

Dynamics of the Toxic Dinoflagellate Alexandrium pacificum in the Taiwan Strait and Its Linkages to Surrounding Populations

Liu

Zheng

Krock

et al. 2021

Water

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The dinoflagellate Alexandrium pacificum can produce paralytic shellfish toxins and is mainly distributed in the Pacific. Blooms of A. pacificum have been frequently reported in offshore areas of the East China Sea, but not along the coast. To investigate the bloom dynamics of A. pacificum and their potential origins in the Taiwan Strait, we performed intensive sampling of both water and sediments from 2017 to 2020. Ellipsoidal cysts were identified as A. pacificum and enumerated based on microscopic observation. Their abundances were quite low but there was a maximum of 9.6 cysts cm−3 in the sediment near the Minjiang River estuary in May 2020, consistent with the high cell abundance in the water column in this area. Cells of A. pacificum were examined using a quantitative polymerase chain reaction, and they appeared to be persistent in the water column across the seasons. High densities of A. pacificum (103 cells L−1) were observed near the Jiulongjiang and Minjiang River estuary in early May 2020, where high nutrients (dissolved inorganic nitrogen and phosphate), and relatively low temperatures (20–21 °C) were also recorded. Strains isolated from the East and South China Sea exhibited the highest division rate (0.63 and 0.93 divisions d−1) at 20 and 23 °C, respectively, but the strain from the Yellow Sea showed the highest division (0.40 divisions d−1) at 17–23 °C. Strains from the East and South China Sea shared similar toxin profiles dominated by the N-sulfocarbamoyl toxins C1/2, but the strain from the Yellow Sea predominantly produced the carbamoyl toxins GTX1/4 and no C1/2. Our results suggest that both cyst germination and persistent cells in the water column might contribute to the bloom formation in the Taiwan Strait. Our results also indicate that the East and South China Sea populations are connected genetically through similar toxin formation but separated from the Yellow Sea population geographically.

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Section: Identifying Populations Based On Physiological Differentiationmentioning

confidence: 82%

Dynamics of the Toxic Dinoflagellate Alexandrium pacificum in the Taiwan Strait and Its Linkages to Surrounding Populations

Liu

Zheng

Krock

et al. 2021

Water

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“…Concerning A. catenella , the predictions suggest a widespread, global distribution. Indeed, the model was quite accurate in its predictions, in the north-western Pacific Ocean [ 94 , 95 , 96 ] and the south-western Pacific Ocean [ 29 , 97 , 98 , 99 ]; South Africa [ 100 ]; South America [ 101 , 102 ]; the Mediterranean Sea [ 103 , 104 ]; and on the eastern shores of North America [ 105 ]; as well as the West Coast [ 106 , 107 ]. An overprediction did occur for certain regions, where no major blooms or occurrences have been recorded, as in some regions of the African continent (although the absence of records could be linked to the very small number of studies); on the Atlantic coast of the Iberian Peninsula (although in this region it could occur in very low concentrations that escape the monitoring programs and phytoplankton studies); and in other European areas, where it is only occasionally reported.…”

Section: Discussionmentioning

confidence: 99%

Projecting Future Climate Change-Mediated Impacts in Three Paralytic Shellfish Toxins-Producing Dinoflagellate Species

Borges

Lopes

Amorim

et al. 2022

Biology

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Toxin-producing microalgae present a significant environmental risk for ecosystems and human societies when they reach concentrations that affect other aquatic organisms or human health. Harmful algal blooms (HAB) have been linked to mass wildlife die-offs and human food poisoning episodes, and climate change has the potential to alter the frequency, magnitude, and geographical extent of such events. Thus, a framework of species distribution models (SDMs), employing MaxEnt modeling, was used to project changes in habitat suitability and distribution of three key paralytic shellfish toxin (PST)-producing dinoflagellate species (i.e., Alexandrium catenella, A. minutum, and Gymnodinium catenatum), up to 2050 and 2100, across four representative concentration pathway scenarios (RCP-2.6, 4.5, 6.0, and 8.5; CMIP5). Despite slightly different responses at the regional level, the global habitat suitability has decreased for all the species, leading to an overall contraction in their tropical and sub-tropical ranges, while considerable expansions are projected in higher latitudes, particularly in the Northern Hemisphere, suggesting poleward distributional shifts. Such trends were exacerbated with increasing RCP severity. Yet, further research is required, with a greater assemblage of environmental predictors and improved occurrence datasets, to gain a more holistic understanding of the potential impacts of climate change on PST-producing species.

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“…In addition, we compared the relationship between salinity and toxin content through transcriptional regulation. The test species A. pacificum (formerly A. tamarense ) is known to produce STXs [ 13 , 24 ] and is widely distributed in the coastal waters of Europe, Australia, Asia, and America [ 43 , 44 , 45 , 46 , 47 ]. In Korea, the species was first recorded in 1985 [ 48 ], and it has been continuously investigated in terms of environmental monitoring and toxicity because of its early spring blooms and toxin outbreaks [ 49 , 50 ].…”

Section: Introductionmentioning

confidence: 99%

Salinity Affects Saxitoxins (STXs) Toxicity in the Dinoflagellate Alexandrium pacificum, with Low Transcription of SXT-Biosynthesis Genes sxtA4 and sxtG

Bui

Kim

Park

et al. 2021

Toxins

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Salinity is an important factor for regulating metabolic processes in aquatic organisms; however, its effects on toxicity and STX biosynthesis gene responses in dinoflagellates require further elucidation. Herein, we evaluated the physiological responses, toxin production, and expression levels of two STX synthesis core genes, sxtA4 and sxtG, in the dinoflagellate Alexandrium pacificum Alex05 under different salinities (20, 25, 30, 35, and 40 psu). Optimal growth was observed at 30 psu (0.12 cell division/d), but cell growth significantly decreased at 20 psu and was irregular at 25 and 40 psu. The cell size increased at lower salinities, with the highest size of 31.5 µm at 20 psu. STXs eq was highest (35.8 fmol/cell) in the exponential phase at 30 psu. GTX4 and C2 were predominant at that time but were replaced by GTX1 and NeoSTX in the stationary phase. However, sxtA4 and sxtG mRNAs were induced, and their patterns were similar in all tested conditions. PCA showed that gene transcriptional levels were not correlated with toxin contents and salinity. These results suggest that A. pacificum may produce the highest amount of toxins at optimal salinity, but sxtA4 and sxtG may be only minimally affected by salinity, even under high salinity stress.

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Resting cysts of Alexandrium catenella and A. pacificum (Dinophyceae) in the Bohai and Yellow Seas, China: Abundance, distribution and implications for toxic algal blooms

Cited by 23 publications

References 44 publications

Dynamics of the Toxic Dinoflagellate Alexandrium pacificum in the Taiwan Strait and Its Linkages to Surrounding Populations

Dynamics of the Toxic Dinoflagellate Alexandrium pacificum in the Taiwan Strait and Its Linkages to Surrounding Populations

Projecting Future Climate Change-Mediated Impacts in Three Paralytic Shellfish Toxins-Producing Dinoflagellate Species

Salinity Affects Saxitoxins (STXs) Toxicity in the Dinoflagellate Alexandrium pacificum, with Low Transcription of SXT-Biosynthesis Genes sxtA4 and sxtG

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