Journal articles: 'Marine algal toxins'

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JAMES, K. J., B. CAREY, J. O'HALLORAN, F. N. A. M. van PELT, and Z. ŠKRABÁKOVÁ. "Shellfish toxicity: human health implications of marine algal toxins." Epidemiology and Infection 138, no. 7 (April 23, 2010): 927–40. http://dx.doi.org/10.1017/s0950268810000853.

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SUMMARYFive major human toxic syndromes caused by the consumption of shellfish contaminated by algal toxins are presented. The increased risks to humans of shellfish toxicity from the prevalence of harmful algal blooms (HABs) may be a consequence of large-scale ecological changes from anthropogenic activities, especially increased eutrophication, marine transport and aquaculture, and global climate change. Improvements in toxin detection methods and increased toxin surveillance programmes are positive developments in limiting human exposure to shellfish toxins.

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Reis Costa. "Advances and Current Challenges in Marine Biotoxins Monitoring." Journal of Marine Science and Engineering 7, no. 9 (September 2, 2019): 302. http://dx.doi.org/10.3390/jmse7090302.

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Aune, T. "Testing for Algal Toxins In Vitro." Alternatives to Laboratory Animals 14, no. 3 (March 1987): 172–73. http://dx.doi.org/10.1177/026119298701400315.

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Toxic blooms of several strains of blue-green algae are found in both natural and man-made freshwater lakes. Furthermore, mussels may accumulate toxic marine dinoflagellates, rendering them toxic to humans. Traditionally, the presence of algal toxins is tested by intraperitoneal injections of extracts in mice. However, toxic waterblooms and mussels can both be detected by means of freshly prepared rat hepatocytes in suspension.

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Echevarria, Michael L., and Alison R. Taylor. "Marine algal neurotoxins: Pandora's box or panacea?" Biochemist 33, no. 3 (June 1, 2011): 14–18. http://dx.doi.org/10.1042/bio03303014.

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Phytoplankton produce a diversity of secondary metabolites that have deleterious effects on other organisms. Some of the most potent of these toxins affect neuronal function in animals. These algal neurotoxins bind selectively to specific receptors on ion transporters in neuronal cell membranes, altering their function and kinetic behaviour. The outcome of such toxin–transporter interactions is the disruption of cell signalling, leading to neurotoxicity through either excitatory or inhibitory mechanisms. Algal neurotoxins may affect non-neuronal cell types as well, but toxic effects are most pronounced in neuronal cells.

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Dolah, Frances M. van, and John S. Ramsdell. "Review and Assessment of In Vitro Detection Methods for Algal Toxins." Journal of AOAC INTERNATIONAL 84, no. 5 (September 1, 2001): 1617–25. http://dx.doi.org/10.1093/jaoac/84.5.1617.

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Abstract Algal toxins produced by marine and freshwater microalgae present a significant analytical challenge because of their complex structures and frequent occurrence as mixtures of structural congeners, which differ in toxic potencies and are present at varying proportions in contaminated samples. Rapid, sensitive in vitro detection methods specific for each class of algal toxins have been developed over the past decade, including immunoassays, enzyme inhibition assays, receptor assays, and cell assays. This review discusses the conceptual approaches to assay development and provides a detailed assessment of the use of in vitro detection methods for marine and freshwater algal toxins.

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Bouchouar, Etran, Samantha Bruzzese, Chelsea Pyles, and Kate Stechyshyn. "Shellfish toxins a public health concern for Canadians." Environmental Health Review 57, no. 01 (March 1, 2014): 16–21. http://dx.doi.org/10.5864/d2014-013.

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Harmful algal blooms (HABs) are increasing worldwide as a result of climate change and global marine traffic. HABs contain high concentrations of algal toxins. Toxin contaminated shellfish cannot be detected by taste, sight, or smell; the toxins are heat-stable and therefore are not destroyed by cooking. Human consumption of toxin-contaminated shellfish leads to illness. Treatment of shellfish poisoning is limited to symptom management. The burden of shellfish poisoning in humans is often underestimated, and the effects of chronic exposure are unknown. Currently there are regulatory practices for shellfish monitoring in Canada and the United States. Yet there is poor communication of HAB risks to the public.

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Selander, E., E. C. Berglund, P. Engström, F. Berggren, J. Eklund, S. Harðardóttir, N. Lundholm, W. Grebner, and M. X. Andersson. "Copepods drive large-scale trait-mediated effects in marine plankton." Science Advances 5, no. 2 (February 2019): eaat5096. http://dx.doi.org/10.1126/sciadv.aat5096.

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Fear of predation may influence food webs more than actual predation. However, the mechanisms and magnitude of nonconsumptive predator effects are largely unknown in unicellular-dominated food webs such as marine plankton. We report a general mechanism of chemically induced predator effects in marine plankton. Copepods, the most abundant zooplankton in the oceans, imprint seawater with unique polar lipids—copepodamides—which trigger toxin production and bioluminescence in harmful dinoflagellates. We show that copepodamides also elicit defensive traits in other phytoplankton, inducing the harmful algal bloom-forming diatom Pseudo-nitzschia seriata to produce 10 times more toxins, and colony-forming diatoms to decrease colony size by half. A 1-year study in the northeast Atlantic revealed that natural copepodamide concentrations are high enough to induce harmful algal toxins and size reduction in dominant primary producers when copepods are abundant. We conclude that copepodamides will structure marine plankton toward smaller, more defended life forms on basin-wide scales.

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MEDLIN, LINDA K., MARINA MONTRESOR, EDNA GRANELI, BEATRIX REUGERA, ROBIN RAINE, BENTE EDVARDSEN, JANE LEWIS, CHRIS ELLIOTT, YOLANDA PAZOS, and LUCIE MARANDA. "MIDTAL (Microarrays for the Detection of Toxic Algae)." Phytotaxa 127, no. 1 (August 29, 2013): 201. http://dx.doi.org/10.11646/phytotaxa.127.1.19.

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Microalgae in marine and brackish waters of Europe regularly cause harmful effects, considered from the human perspective, in that they cause economic damage to fisheries and tourism. Cyanobacteria cause similar problems in freshwaters. These episodes encompass a broad range of phenomena collectively referred to as harmful algal blooms (HABs). For adequate management of these phenomena, monitoring of microalgae is required. However, present day monitoring is time consuming and based on morphology as determined by light microscopy, which may be insufficient to give definitive species and toxin attribution. In the European Union (EU) FP7 project MIDTAL (microarrays for the detection of toxic algae), we will first target rapid species identification using rRNA genes. The variable regions of the rRNA genes can be used for probe design to recognize species or even strains. Second, a toxin based microarray will be developed that includes antibody reactions to specific toxins produced by these microalgae because even when cell numbers are low, toxins can be present and can accumulate in the shellfish. Microarrays are the state of the art technology in molecular biology for the processing of bulk samples for detection of target RNA/DNA sequence. Existing rRNA probes and antibodies for toxic algal species/strains and their toxins will be adapted and optimized for microarray use. The purpose of MIDTAL is to support the common fisheries policy and to aid the national monitoring agencies by providing new rapid tools for the identification of toxic algae and their toxins so they can comply with EU directive 91/1491/CEE to monitor for toxic algae, and reduce the need for the mouse bioassay.

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Corriere, Mauro, Lucía Soliño, and Pedro Reis Costa. "Effects of the Marine Biotoxins Okadaic Acid and Dinophysistoxins on Fish." Journal of Marine Science and Engineering 9, no. 3 (March 7, 2021): 293. http://dx.doi.org/10.3390/jmse9030293.

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Natural high proliferations of toxin-producing microorganisms in marine and freshwater environments result in dreadful consequences at the socioeconomically and environmental level due to water and seafood contamination. Monitoring programs and scientific evidence point to harmful algal blooms (HABs) increasing in frequency and intensity as a result of global climate alterations. Among marine toxins, the okadaic acid (OA) and the related dinophysistoxins (DTX) are the most frequently reported in EU waters, mainly in shellfish species. These toxins are responsible for human syndrome diarrhetic shellfish poisoning (DSP). Fish, like other marine species, are also exposed to HABs and their toxins. However, reduced attention has been given to exposure, accumulation, and effects on fish of DSP toxins, such as OA. The present review intends to summarize the current knowledge of the impact of DSP toxins and to identify the main issues needing further research. From data reviewed in this work, it is clear that exposure of fish to DSP toxins causes a range of negative effects, from behavioral and morphological alterations to death. However, there is still much to be investigated about the ecological and food safety risks related to contamination of fish with DSP toxins.

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Plumley, F. Gerald. "Marine algal toxins: Biochemistry, genetics, and molecular biology." Limnology and Oceanography 42, no. 5part2 (July 1997): 1252–64. http://dx.doi.org/10.4319/lo.1997.42.5_part_2.1252.

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Goya, Alejandra B., Danial Baqer, Ryan P. Alexander, Patrycja Stubbs, Karl Dean, Adam M. Lewis, Lewis Coates, Benjamin H. Maskrey, and Andrew D. Turner. "Marine Biotoxins in Whole and Processed Scallops from the Argentine Sea." Marine Drugs 20, no. 10 (October 10, 2022): 634. http://dx.doi.org/10.3390/md20100634.

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Harmful algal blooms are an increasing worldwide threat to the seafood industry and human health as a consequence of the natural production of biotoxins that can accumulate in shellfish. In the Argentine Sea, this has been identified as an issue for the offshore fisheries of Patagonian scallops (Zygochlamys patagonica), leading to potentially harmful effects on consumers. Here we assess spatial and temporal patterns in marine biotoxin concentrations in Patagonian scallops harvested in Argentinian waters between 2012–2017, based on analyses for paralytic shellfish toxins, lipophilic toxins, and amnesic shellfish toxins. There was no evidence for concentrations of lipophilic or amnesic toxins above regulatory acceptance thresholds, with trace concentrations of pectenotoxin 2, azaspiracid 2 and okadaic acid group toxins confirmed. Conversely, paralytic shellfish toxins were quantified in some scallops. Gonyautoxins 1 and 2 dominated the unusual toxin profiles (91%) in terms of saxitoxin equivalents with maximum concentrations reaching 3985 µg STX eq/kg and with changes in profiles linked in part to seasonal changes. Total toxin concentrations were compared between samples of the adductor muscle and whole tissue, with results showing the absence of toxins in the adductor muscle confirming toxin accumulation in the digestive tracts of the scallops and the absence of a human health threat following the processing of scallop adductor meat. These findings highlight that paralytic shellfish toxins with an unusual toxin profile can occur in relatively high concentrations in whole Patagonian scallops in specific regions and during particular time periods, also showing that the processing of scallops on board factory ships to obtain frozen adductor muscle is an effective management process that minimizes the risk of poisonings from final products destined for human consumption.

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Fire, Spencer E., Andrea Bogomolni, Robert A. DiGiovanni, Greg Early, Tod A. Leighfield, Keith Matassa, Glenn A. Miller, et al. "An assessment of temporal, spatial and taxonomic trends in harmful algal toxin exposure in stranded marine mammals from the U.S. New England coast." PLOS ONE 16, no. 1 (January 6, 2021): e0243570. http://dx.doi.org/10.1371/journal.pone.0243570.

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Despite a long-documented history of severe harmful algal blooms (HABs) in New England coastal waters, corresponding HAB-associated marine mammal mortality events in this region are far less frequent or severe relative to other regions where HABs are common. This long-term survey of the HAB toxins saxitoxin (STX) and domoic acid (DA) demonstrates significant and widespread exposure of these toxins in New England marine mammals, across multiple geographic, temporal and taxonomic groups. Overall, 19% of the 458 animals tested positive for one or more toxins, with 15% and 7% testing positive for STX and DA, respectively. 74% of the 23 different species analyzed demonstrated evidence of toxin exposure. STX was most prevalent in Maine coastal waters, most frequently detected in common dolphins (Delphinus delphis), and most often detected during July and October. DA was most prevalent in animals sampled in offshore locations and in bycaught animals, and most frequently detected in mysticetes, with humpback whales (Megaptera novaeangliae) testing positive at the highest rates. Feces and urine appeared to be the sample matrices most useful for determining the presence of toxins in an exposed animal, with feces samples having the highest concentrations of STX or DA. No relationship was found between the bloom season of toxin-producing phytoplankton and toxin detection rates, however STX was more likely to be present in July and October. No relationship between marine mammal dietary preference and frequency of toxin detection was observed. These findings are an important part of a framework for assessing future marine mammal morbidity and mortality events, as well as monitoring ecosystem health using marine mammals as sentinel organisms for predicting coastal ocean changes.

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Hayashi, Aiko, Juan José Dorantes-Aranda, John Bowman, and Gustaaf Hallegraeff. "Combined Cytotoxicity of the Phycotoxin Okadaic Acid and Mycotoxins on Intestinal and Neuroblastoma Human Cell Models." Toxins 10, no. 12 (December 8, 2018): 526. http://dx.doi.org/10.3390/toxins10120526.

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Mycotoxins are emerging toxins in the marine environment, which can co-occur with algal toxins to exert synergistic or antagonistic effects for human seafood consumption. The current study assesses the cytotoxicity of the algal toxin okadaic acid, shellfish, and dust storm-associated mycotoxins alone or in combination on human intestinal (HT-29) and neuroblastoma (SH-SY5Y) cell lines. Based on calculated IC50 (inhibitory concentration 50%) values, mycotoxins and the algal toxin on their own exhibited increased cytotoxicity in the order of sydowinin A < sydowinin B << patulin < alamethicin < sydowinol << gliotoxin ≈ okadaic acid against the HT-29 cell line, and sydowinin B < sydowinin A << alamethicin ≈ sydowinol < patulin, << gliotoxin < okadaic acid against the SH-SY5Y cell line. Combinations of okadaic acid–sydowinin A, –alamethicin, –patulin, and –gliotoxin exhibited antagonistic effects at low-moderate cytotoxicity, but became synergistic at high cytotoxicity, while okadaic acid–sydowinol displayed an antagonistic relationship against HT-29 cells. Furthermore, only okadaic acid–sydowinin A showed synergism, while okadaic acid–sydowinol, –alamethicin, –patulin, and –gliotoxin combinations demonstrated antagonism against SH-SY5Y. While diarrhetic shellfish poisoning (DSP) from okadaic acid and analogues in many parts of the world is considered to be a comparatively minor seafood toxin syndrome, our human cell model studies suggest that synergisms with certain mycotoxins may aggravate human health impacts, depending on the concentrations. These findings highlight the issues of the shortcomings of current regulatory approaches, which do not regulate for mycotoxins in shellfish and treat seafood toxins as if they occur as single toxins.

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Gordon, Christopher J., and John S. Ramsdell. "Effects of marine algal toxins on thermoregulation in mice." Neurotoxicology and Teratology 27, no. 5 (September 2005): 727–31. http://dx.doi.org/10.1016/j.ntt.2005.06.012.

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Bowen, Lizabeth, Susan Knowles, Kathi Lefebvre, Michelle St. Martin, Michael Murray, Kim Kloecker, Daniel Monson, et al. "Divergent Gene Expression Profiles in Alaskan Sea Otters: An Indicator of Chronic Domoic Acid Exposure?" Oceans 3, no. 3 (August 8, 2022): 401–18. http://dx.doi.org/10.3390/oceans3030027.

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An opportunistic investigation into ecosystem instability in Kachemak Bay (KBay), Alaska, has led us to investigate exposure to toxic algae in sea otters. We used gene expression to explore the physiological health of sea otters sampled in KBay in May 2019. We found altered levels of gene transcripts in comparison with reference sea otters from clinically normal, oil-exposed, and nutritionally challenged populations sampled over the past decade. KBay sea otters were markedly divergent from the other groups for five genes, which indicated the involvement of neurological, cardiac, immune, and detoxification systems. Further, analyses of urine and fecal samples detected domoic acid in the KBay sea otters. In combination, these results may point to chronic, low-level exposure to an algal toxin, such as domoic acid. With a warming climate, the frequency and severity of harmful algal blooms in marine environments is anticipated to increase, and novel molecular technologies to detect sublethal or chronic exposure to algal toxins will help provide an early warning of threats to the stability of populations and ecosystems.

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McPartlin, Daniel A., Michael J. Lochhead, Laurie B. Connell, Gregory J. Doucette, and Richard J. O'Kennedy. "Use of biosensors for the detection of marine toxins." Essays in Biochemistry 60, no. 1 (June 30, 2016): 49–58. http://dx.doi.org/10.1042/ebc20150006.

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Increasing occurrences of harmful algal blooms (HABs) in the ocean are a major concern for countries around the globe, and with strong links between HABs and climate change and eutrophication, the occurrences are only set to increase. Of particular concern with regard to HABs is the presence of toxin-producing algae. Six major marine biotoxin groups are associated with HABs. Ingestion of such toxins via contaminated shellfish, fish, or other potential vectors, can lead to intoxication syndromes with moderate to severe symptoms, including death in extreme cases. There are also major economic implications associated with the diverse effects of marine biotoxins and HABs. Thus, effective monitoring programmes are required to manage and mitigate their detrimental global effect. However, currently legislated detection methods are labour-intensive, expensive and relatively slow. The growing field of biosensor diagnostic devices is an exciting area that has the potential to produce robust, easy-to-use, cost-effective, rapid and accurate detection methods for marine biotoxins and HABs. This review discusses recently developed biosensor assays that target marine biotoxins and their microbial producers, both in harvested fish/shellfish samples and in the open ocean. The effective deployment of such biosensor platforms could address the pressing need for improved monitoring of HABs and marine biotoxins, and could help to reduce their global economic impact.

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Puri, Munish. "Algal biotechnology for pursuing omega-3 fatty acid (bioactive) production." Microbiology Australia 38, no. 2 (2017): 85. http://dx.doi.org/10.1071/ma17036.

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Algae are spread in diversified ecosystems that include marine, freshwater, desert and hot springs and even snow and ice environments. Algae are classified as multicellular large sea weeds (macroalgae) or unicellular microalgae. Macroalgae are targeted for mining of natural biologically active components, which include proteins, linear peptides, cyclic peptides, and amino acids1. Recently, microalgae have been exploited for the production of high-value compounds such as lipids (omega-3 fatty acids), enzymes, polymers, toxins, antioxidants, and pigments (carotenoids)2. Thus, algal biotechnology is defined as ‘the technology developed using algae (macro or micro) to make or modify bioactive compounds, or products (nutritional supplements, fine chemicals) and renewable fuels for specific use’.

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Raposo, Mariana I. C., Maria Teresa S. R. Gomes, Maria João Botelho, and Alisa Rudnitskaya. "Paralytic Shellfish Toxins (PST)-Transforming Enzymes: A Review." Toxins 12, no. 5 (May 22, 2020): 344. http://dx.doi.org/10.3390/toxins12050344.

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Paralytic shellfish toxins (PSTs) are a group of toxins that cause paralytic shellfish poisoning through blockage of voltage-gated sodium channels. PSTs are produced by prokaryotic freshwater cyanobacteria and eukaryotic marine dinoflagellates. Proliferation of toxic algae species can lead to harmful algal blooms, during which seafood accumulate high levels of PSTs, posing a health threat to consumers. The existence of PST-transforming enzymes was first remarked due to the divergence of PST profiles and concentrations between contaminated bivalves and toxigenic organisms. Later, several enzymes involved in PST transformation, synthesis and elimination have been identified. The knowledge of PST-transforming enzymes is necessary for understanding the processes of toxin accumulation and depuration in mollusk bivalves. Furthermore, PST-transforming enzymes facilitate the obtainment of pure analogues of toxins as in natural sources they are present in a mixture. Pure compounds are of interest for the development of drug candidates and as analytical reference materials. PST-transforming enzymes can also be employed for the development of analytical tools for toxin detection. This review summarizes the PST-transforming enzymes identified so far in living organisms from bacteria to humans, with special emphasis on bivalves, cyanobacteria and dinoflagellates, and discusses enzymes’ biological functions and potential practical applications.

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Krahl, Pamela L. "Harmful Algal Bloom-Associated Marine Toxins: A Risk Assessment Framework." Archives of Environmental & Occupational Health 64, no. 2 (July 2009): 129–34. http://dx.doi.org/10.3200/aeoh.64.2.129-134.

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Dolah, Frances M. Van. "Marine Algal Toxins: Origins, Health Effects, and Their Increased Occurrence." Environmental Health Perspectives 108 (March 2000): 133. http://dx.doi.org/10.2307/3454638.

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Danil, Kerri, Michelle Berman, Elizabeth Frame, Antonella Preti, Spencer E. Fire, Tod Leighfield, Jim Carretta, Melissa L. Carter, and Kathi Lefebvre. "Marine algal toxins and their vectors in southern California cetaceans." Harmful Algae 103 (March 2021): 102000. http://dx.doi.org/10.1016/j.hal.2021.102000.

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Shetty, Kateel G., Jacqueline V. Huntzicker, Kathleen S. Rein, and Krish Jayachandran. "Biodegradation of polyether algal toxins–Isolation of potential marine bacteria." Journal of Environmental Science and Health, Part A 45, no. 14 (November 2, 2010): 1850–57. http://dx.doi.org/10.1080/10934529.2010.520510.

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Van Dolah, F. M. "Marine algal toxins: origins, health effects, and their increased occurrence." Environmental Health Perspectives 108, suppl 1 (March 2000): 133–41. http://dx.doi.org/10.1289/ehp.00108s1133.

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Guillotin, Sophie, and Nicolas Delcourt. "Marine Neurotoxins’ Effects on Environmental and Human Health: An OMICS Overview." Marine Drugs 20, no. 1 (December 23, 2021): 18. http://dx.doi.org/10.3390/md20010018.

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Harmful algal blooms (HAB), and the consequent release of toxic metabolites, can be responsible for seafood poisoning outbreaks. Marine wildlife can accumulate these toxins throughout the food chain, which presents a threat to consumers’ health. Some of these toxins, such as saxitoxin (STX), domoic acid (DA), ciguatoxin (CTX), brevetoxin (BTX), tetrodotoxin (TTX), and β-N-methylamino-L-alanine (BMAA), cause severe neurological symptoms in humans. Considerable information is missing, however, notably the consequences of toxin exposures on changes in gene expression, protein profile, and metabolic pathways. This information could lead to understanding the consequence of marine neurotoxin exposure in aquatic organisms and humans. Nevertheless, recent contributions to the knowledge of neurotoxins arise from OMICS-based research, such as genomics, transcriptomics, proteomics, and metabolomics. This review presents a comprehensive overview of the most recent research and of the available solutions to explore OMICS datasets in order to identify new features in terms of ecotoxicology, food safety, and human health. In addition, future perspectives in OMICS studies are discussed.

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Pyenson, Nicholas D., Carolina S. Gutstein, James F. Parham, Jacobus P. Le Roux, Catalina Carreño Chavarría, Holly Little, Adam Metallo, et al. "Repeated mass strandings of Miocene marine mammals from Atacama Region of Chile point to sudden death at sea." Proceedings of the Royal Society B: Biological Sciences 281, no. 1781 (April 22, 2014): 20133316. http://dx.doi.org/10.1098/rspb.2013.3316.

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Marine mammal mass strandings have occurred for millions of years, but their origins defy singular explanations. Beyond human causes, mass strandings have been attributed to herding behaviour, large-scale oceanographic fronts and harmful algal blooms (HABs). Because algal toxins cause organ failure in marine mammals, HABs are the most common mass stranding agent with broad geographical and widespread taxonomic impact. Toxin-mediated mortalities in marine food webs have the potential to occur over geological timescales, but direct evidence for their antiquity has been lacking. Here, we describe an unusually dense accumulation of fossil marine vertebrates from Cerro Ballena, a Late Miocene locality in Atacama Region of Chile, preserving over 40 skeletons of rorqual whales, sperm whales, seals, aquatic sloths, walrus-whales and predatory bony fish. Marine mammal skeletons are distributed in four discrete horizons at the site, representing a recurring accumulation mechanism. Taphonomic analysis points to strong spatial focusing with a rapid death mechanism at sea, before being buried on a barrier-protected supratidal flat. In modern settings, HABs are the only known natural cause for such repeated, multispecies accumulations. This proposed agent suggests that upwelling zones elsewhere in the world should preserve fossil marine vertebrate accumulations in similar modes and densities.

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Tardivo Kubis, Jonás Adrián, Francisco Rodríguez, Araceli E. Rossignoli, Pilar Riobó, Eugenia A. Sar, and Inés Sunesen. "Morphological, Phylogenetic and Toxinological Characterization of Potentially Harmful Algal Species from the Marine Coastal Waters of Buenos Aires Province (Argentina)." Phycology 3, no. 1 (February 7, 2023): 79–105. http://dx.doi.org/10.3390/phycology3010006.

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In the framework of a monitoring program of harmful microalgae from the marine coastal waters of the Buenos Aires Province, seven strains were isolated and characterized by morphological and molecular analysis (LSU rDNA partial sequencing, D1–D3 regions). Established strains belonged to Alexandrium catenella, Protoceratium reticulatum and Pseudo-nitzschia multiseries. The toxinological profile of the target strains were determined by UHPLC-FLD equipment for paralytic shellfish toxins (PSTs) and LC-MS/MS for lipophilic (LSTs) and amnesic toxins (ASTs). The toxin profile varied in the four strains of A. catenella, the predominant compounds were gonyautoxins (GTXs) GTX2,3 and GTX1,4 for strains LPCc001 and LPCc004, and N-sulfocarbamoyl toxins (Cs) C1,2 and GTX1,4 for strains LPCc002 and LPCc008. The obtained cellular toxicity values were moderate-to-high (12.38–46.40 pg saxitoxin equiv. cell−1). The toxin profile of P. reticulatum was dominated by yessotoxins (YTXs) (up to 94.40 pg cell−1) accompanied by homo-yessotoxin (Homo-YTX) traces. In P. multiseries, the toxin profiles were dominated by domoic acid (DA) (1.62 pg cell−1 and 1.09 pg cell−1) and secondarily by Isomer A (Iso-A), Epi-domoic acid (Epi-DA), Isomer-E (Iso-E) and Isomer-D (Iso-D). This study provides detailed information about representative HAB species in the area, useful for resource management, risk evaluation and related research on toxic dinoflagellates and diatoms.

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Brandenburg, Karen, Laura Siebers, Joost Keuskamp, Thomas G. Jephcott, and Dedmer B. Van de Waal. "Effects of Nutrient Limitation on the Synthesis of N-Rich Phytoplankton Toxins: A Meta-Analysis." Toxins 12, no. 4 (April 1, 2020): 221. http://dx.doi.org/10.3390/toxins12040221.

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Eutrophication has played a major role in the worldwide increase of harmful algal blooms (HABs). Higher input of key nutrients, such as nitrogen (N) and phosphorus (P), can stimulate the growth of harmful algal species in freshwater, estuarine, and coastal marine ecosystems. Some HAB-forming taxa, particularly several cyanobacteria and dinoflagellate species, are harmful through the production of N-rich toxins that have detrimental effects on the environment and human health. Here, we test how changes in nutrient availability affect N-rich toxin synthesis in cyanobacteria and dinoflagellates using a meta-analysis approach. Overall, N-rich toxin content showed an increase with P limitation, while it tended to decrease with N limitation, but we also observed substantial variation in responses both within and across genera and toxin groups. For instance, in response to N limitation, microcystin content varied from a 297% decrease up to a 273% increase, and paralytic shellfish poisoning (PSP) toxin content varied from a 204% decrease to an 82% increase. Cylindrospermopsin, produced by N2-fixing cyanobacteria, showed no clear direction in response to nutrient limitation, and cellular contents of this compound may thus vary independently of nutrient fluctuations. Our results confirm earlier reported stoichiometric regulation of N-rich phytoplankton toxins, showing increased toxin content with an increase in cellular N:P ratios, and vice versa. Thus, changes in N-rich toxin content largely follow the changes in relative cellular N content. Consequently, although nutrient limitation may limit bloom biomass and thereby bloom toxicity, our results warn that P limitation can cause accumulation of cellular toxins and thus lead to unexpected increases in bloom toxicity.

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Luckas, Bernd. "Phycotoxins in the marine environment: control of marine organisms for contamination with algal toxins." International Journal of Environment and Pollution 13, no. 1/2/3/4/5/6 (2000): 148. http://dx.doi.org/10.1504/ijep.2000.002314.

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FRIEDMAN, MELISSA A., and BONNIE E. LEVIN. "Neurobehavioral effects of harmful algal bloom (HAB) toxins: A critical review." Journal of the International Neuropsychological Society 11, no. 3 (May 2005): 331–38. http://dx.doi.org/10.1017/s1355617705050381.

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Human exposure to naturally occurring marine toxins has been associated with a range of neurobehavioral abnormalities. The toxins are produced by harmful algal blooms (HABs) and are typically contracted through seafood consumption. The primary target of many of the HAB toxins is the neurologic system, and the neurobehavioral symptoms associated with the HAB illnesses have influenced public health policy. The HAB-related illnesses most frequently linked to neuropsychological disturbance are Amnesic Shellfish Poisoning, Ciguatera Fish Poisoning, and Possible Estuarine Associated Syndrome, which is associated with exposure to thePfiesteria piscicidaorganism. Although the neurophysiologic mechanisms underlying many of the HAB illnesses have been well delineated, the literature examining the neuropsychological impairments is unclear and needs to be defined. This review is intended to introduce an emerging area of study linking HAB illnesses with neuropsychological changes. (JINS, 2005,11, 331–338.)

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Olding, Daniel D. "Algal Communities as a Biological Indicator of Stormwater Management Pond Performance and Function." Water Quality Research Journal 35, no. 3 (August 1, 2000): 489–504. http://dx.doi.org/10.2166/wqrj.2000.029.

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Abstract An investigation into phytoplankton and periphyton algal communities of two recently constructed Stormwater management ponds suggests that Stormwater impacts on biological communities are reduced during passage through the ponds, providing a degree of protection for biological communities in their receiving waters. In both ponds, disturbance effects from the incoming Stormwater on algal community richness and evenness appear to be greatest in the sediment forebay and are reduced in the main pond. However, the nature of the disturbance in the two systems can be seen to be fundamentally different from a biological perspective, with Rouge Pond functioning primarily to reduce toxins harmful to algal communities (e.g., heavy metals), and Harding Pond acting to reduce nutrients. The taxonomic composition of the two sites provides an indication of the quality of the incoming Stormwater. Rouge Pond, which contains many marine and brackish water species, receives Stormwater runoff from a major highway, while Harding Pond, containing more nutrient rich species, receives Stormwater primarily from residential properties. Despite the nutrient-rich conditions present in both ponds, nuisance blue-green algae (cyanobacte-ria) are conspicuously absent, and the ponds appear to have little potential for developing harmful algal blooms. The lack of blue-green algae can be linked to the hydraulic functioning of the ponds, suggesting that Stormwater facilities may be engineered to inhibit undesirable algal communities.

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Tamele, Isidro, Marisa Silva, and Vitor Vasconcelos. "The Incidence of Marine Toxins and the Associated Seafood Poisoning Episodes in the African Countries of the Indian Ocean and the Red Sea." Toxins 11, no. 1 (January 21, 2019): 58. http://dx.doi.org/10.3390/toxins11010058.

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The occurrence of Harmful Algal Blooms (HABs) and bacteria can be one of the great threats to public health due to their ability to produce marine toxins (MTs). The most reported MTs include paralytic shellfish toxins (PSTs), amnesic shellfish toxins (ASTs), diarrheic shellfish toxins (DSTs), cyclic imines (CIs), ciguatoxins (CTXs), azaspiracids (AZTs), palytoxin (PlTXs), tetrodotoxins (TTXs) and their analogs, some of them leading to fatal outcomes. MTs have been reported in several marine organisms causing human poisoning incidents since these organisms constitute the food basis of coastal human populations. In African countries of the Indian Ocean and the Red Sea, to date, only South Africa has a specific monitoring program for MTs and some other countries count only with respect to centers of seafood poisoning control. Therefore, the aim of this review is to evaluate the occurrence of MTs and associated poisoning episodes as a contribution to public health and monitoring programs as an MT risk assessment tool for this geographic region.

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Mudadu, Alessandro G., Anna Maria Bazzoni, Virgilio Congiu, Giuseppe Esposito, Alberto Cesarani, Rita Melillo, Giuseppa Lorenzoni, et al. "Longitudinal Study on Seasonal Variation of Marine Biotoxins and Related Harmful Algae in Bivalve Mollusks Bred in Sardinia (Italy, W Mediterranean Sea) from 2015 to 2020 and Assessment of Potential Public Health Risks." Journal of Marine Science and Engineering 9, no. 5 (May 9, 2021): 510. http://dx.doi.org/10.3390/jmse9050510.

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Annual and interannual dynamics of shellfish toxins and associated harmful algal species (HAS) were analyzed from 2015 to 2020 in Tortolì Lagoon (Sardinia, west Mediterranean Sea). Analysis of seasonal occurrence of different harmful algae, such as Dinophysis spp., Prorocentrum spp., Pseudo-nitzschia spp. and Alexandrium minutum, was performed. The species Dinophysis acuminata and Dinophysis sacculus were responsible for the accumulation of lipophilic toxins belonging to the okadaic acid group (OAs) and pectenotoxins2 (PTX2) in bivalve mollusks. The highest HAS detection was recorded in the winter months; in particular, Dinophysis spp. was mostly present in January–February. Out of 1090 analyzed mollusk samples, 39 were non-compliant, exceeding the legal limits (160 μg OA eq/kg e.p.) reported in Regulation 853/2004 of the European Commission. A statistical analysis related to the presence of OA and PTX2 in mollusks with various environmental parameters (pH, water temperature, dissolved oxygen, algal density) was implemented, proving a clear winter seasonality. The present study highlights the necessity to better understand the different factors able to influence the production and accumulation of toxins in bivalve mollusks bred in an important Sardinian production area. The contribution of this research is important not only from an environmental and productive point of view but also from the view of implementing management in order to mitigate any harm to human health.

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Estevez, Pablo, and Ana Gago-Martinez. "Contribution of Mass Spectrometry to the Advances in Risk Characterization of Marine Biotoxins: Towards the Characterization of Metabolites Implied in Human Intoxications." Toxins 15, no. 2 (January 22, 2023): 103. http://dx.doi.org/10.3390/toxins15020103.

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A significant spread and prevalence of algal toxins and, in particular, marine biotoxins have been observed worldwide over the last decades. Marine biotoxins are natural contaminants produced during harmful algal blooms being accumulated in seafood, thus representing a threat to human health. Significant progress has been made in the last few years in the development of analytical methods able to evaluate and characterize the different toxic analogs involved in the contamination, Liquid Chromatography coupled to different detection modes, including Mass Spectrometry, the method of choice due to its potential for separation, identification, quantitation and even confirmation of the different above-mentioned analogs. Despite this, the risk characterization in humans is still limited, due to several reasons, including the lack of reference materials or even the limited access to biological samples from humans intoxicated during these toxic events and episodes, which hampered the advances in the evaluation of the metabolites responsible for the toxicity in humans. Mass Spectrometry has been proven to be a very powerful tool for confirmation, and in fact, it is playing an important role in the characterization of the new biotoxins analogs. The toxin metabolization in humans is still uncertain in most cases and needs further research in which the implementation of Mass Spectrometric methods is critical. This review is focused on compiling the most relevant information available regarding the metabolization of several marine biotoxins groups, which were identified using Mass Spectrometry after the in vitro exposition of these toxins to liver microsomes and hepatocytes. Information about the presence of metabolites in human samples, such as human urine after intoxication, which could also be used as potential biomarkers for diagnostic purposes, is also presented.

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Otero, Paz, and Marisa Silva. "Emerging Marine Biotoxins in European Waters: Potential Risks and Analytical Challenges." Marine Drugs 20, no. 3 (March 8, 2022): 199. http://dx.doi.org/10.3390/md20030199.

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Harmful algal blooms pose a challenge regarding food safety due to their erratic nature and forming circumstances which are yet to be disclosed. The best strategy to protect human consumers is through legislation and monitoring strategies. Global warming and anthropological intervention aided the migration and establishment of emerging toxin producers into Europe’s temperate waters, creating a new threat to human public health. The lack of information, standards, and reference materials delay effective solutions, being a matter of urgent resolution. In this work, the recent findings of the presence of emerging azaspiracids, spirolildes, pinnatoxins, gymnodimines, palitoxins, ciguatoxins, brevetoxins, and tetrodotoxins on European Coasts are addressed. The information concerning emerging toxins such as new matrices, locations, and toxicity assays is paramount to set the risk assessment guidelines, regulatory levels, and analytical methodology that would protect the consumers.

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Donovan, Carrie J., Rafael A. Garduño, Martin Kalmokoff, John C. Ku, Michael A. Quilliam, and Tom A. Gill. "Pseudoalteromonas Bacteria Are Capable of Degrading Paralytic Shellfish Toxins." Applied and Environmental Microbiology 75, no. 21 (August 28, 2009): 6919–23. http://dx.doi.org/10.1128/aem.01384-09.

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ABSTRACT Marine bacterial isolates cultured from the digestive tracts of blue mussels (Mytilus edulis) contaminated with paralytic shellfish toxins (PSTs) were screened for the ability to reduce the toxicity of a PST mixture. Seven isolates reduced the overall toxicity of the algal extract by ≥90% within 3 days. These isolates shared at least 99% 16S rRNA gene sequence similarity with five Pseudoalteromonas spp. Phenotypic tests suggested that all are novel strains of Pseudoalteromonas haloplanktis.

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Pomponi, Shirley A., Daniel G. Baden, and Yonathan Zohar. "Marine Biotechnology: Realizing the Potential." Marine Technology Society Journal 41, no. 3 (September 1, 2007): 24–31. http://dx.doi.org/10.4031/002533207787442132.

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Marine biotechnology is an applied science, the goal of which is to develop goods and services from marine organisms and processes. The new wave of marine biotechnology research began in the early 1980s and includes some significant success stories. A new drug to manage pain is commercially available, and a new cancer drug has been recommended for approval, the first from a fish-eating snail and the second from a mangrove tunicate. Enzymes from hydrothermal vent microbes are routinely used in PCR reactions, and marine-derived molecular probes are helping understand the molecular basis of disease processes. Advances in aquaculture biotechnology have resulted in more efficient production of finfish and shellfish for human consumption, and polyunsaturated fatty acids from marine microalgae are used as nutritional supplements for adults and infants. Rapid diagnostic tools have been developed to monitor toxins in the environment and in seafood, and genetic fingerprinting techniques are helping to control illegal trade of threatened marine species. In the future, multidisciplinary programs in oceans and human health should focus not only on microbial pathogens and harmful algal bloom toxins but also on discovery of new chemicals to prevent or treat human diseases. And the development of biological and biochemical sensors to detect pathogens, contaminants, and toxins and to monitor human and environmental health indicators in the marine environment should be a very high priority in the establishment of U.S. coastal ocean observing systems.

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Lopes, Vanessa, Ana Lopes, Pedro Costa, and Rui Rosa. "Cephalopods as Vectors of Harmful Algal Bloom Toxins in Marine Food Webs." Marine Drugs 11, no. 9 (September 6, 2013): 3381–409. http://dx.doi.org/10.3390/md11093381.

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Kerr, D. S., D. M. Briggs, and H. I. Saba. "A neurophysiological method of rapid detection and analysis of marine algal toxins." Toxicon 37, no. 12 (December 1999): 1803–25. http://dx.doi.org/10.1016/s0041-0101(99)00124-5.

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Al Muftah, Abdulrahman, Andrew I. Selwood, Amanda J. Foss, Hareb Mohammed S. J. Al-Jabri, Malcolm Potts, and Mete Yilmaz. "Algal toxins and producers in the marine waters of Qatar, Arabian Gulf." Toxicon 122 (November 2016): 54–66. http://dx.doi.org/10.1016/j.toxicon.2016.09.016.

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Thuduhena, Anjana Chamilka. "The HARMFUL CYANOBACTERIAL BLOOMS AND DEVELOPED CYANOPHAGES AS A BIOLOGICAL SOLUTION." Bacterial Empire 2, no. 1 (January 14, 2019): 6. http://dx.doi.org/10.36547/be.2019.2.1.6-9.

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Abstract Cyanobacterial Harmful Algal blooms (CHABs) cause devastating impacts to fisheries, tourism, public health and ecosystem around the world, and have increased in frequency. Cyanobacterial blooms occur in fresh water and marine environments, producing a variety of toxins, and poisoning risks to humans and animals. Chemicals can be used to kill cyanobacteria. Unfortunately, many of these chemicals are toxic to other forms of life, including fish and organisms they eat. The use of chemicals in natural lakes could create more problems than they solve, is not permitted. Cyanophage is a double-stranded DNA virus that infects cyanobacteria and is detected in both freshwater and marine environments as a biological solution developed Cyanophages can use for long term treatment options. Key words: Cyanobacterial Harmful Algal blooms, Cyanophage, DNA Viruses

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Mishra, R. K. "The Effect of Eutrophication on Drinking Water." British Journal of Multidisciplinary and Advanced Studies 4, no. 1 (January 19, 2023): 7–20. http://dx.doi.org/10.37745/bjmas.2022.0096.

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The effects of eutrophication on the environment may have deteriorate consequences of health of exposed animal and human populations through various path way’s. when fresh water, extracted from eutrophic areas, is used for the production of drinking water severe impacts can also occur during watering in eutrophic waters. eutrophication is complex processes which occurs both in fresh and marine waters, where certain types of algae disturbs the aquatic ecosystem and become a threat for animals and human health the primary cause of eutrophication is an excessive concentration of plant nutrient’s originating from agriculture of sewage treatment. The main cause of eutrophication is the large input of nutrient mixed to water body and the main effect is imbalance in the food web that results in the high levels of phytoplankton, zooplankton, algae biomass in stratified water bodies. This can lead algal blooms. The direct consequences is in an excess of oxygen consumption near bottom of the water body. eutrophication processes can be divided in to two categories depending on weather they are linked to the nutrients dispersion and phytoplankaton growth to oxygen cycle near the bottom of the water body. Various effects can be observed depending upon the severity of the eutrophication. Treatment of eutrophic water for producing drinking water. algae disturbs the aquatic ecosystems a threat for animal and human health..eutrophication concern the availability of oxygens. Some species of algae may also contain toxins but incidents where fresh water algae or the origin of cause human or animal illness. Some cynobacteria have capacity to produces toxins dangerous to human beings. A variety of symptoms depending on toxins implicated our observed such as fatigues, headache, diarrhoea, vomiting, and some throat fever skin irritations. Good practices to inform people about risks of bathing or sporting activity in normally colored or turbid waters. Allergic bathers of people walking along shore of water body affected by algae blooms. Any allergies releasing not only toxin but also allergic compounds. In some specific case; local authorities must rely on eutrophic water for producing drinking water.

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Ben-Gigirey, Begoña, Lucía Soliño, Isabel Bravo, Francisco Rodríguez, and María V. M. Casero. "Paralytic and Amnesic Shellfish Toxins Impacts on Seabirds, Analyses and Management." Toxins 13, no. 7 (June 29, 2021): 454. http://dx.doi.org/10.3390/toxins13070454.

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Marine biotoxins have been frequently implicated in morbidity and mortality events in numerous species of birds worldwide. Nevertheless, their effects on seabirds have often been overlooked and the associated ecological impact has not been extensively studied. On top of that, the number of published studies confirming by analyses the presence of marine biotoxins from harmful algal blooms (HABs) in seabirds, although having increased in recent years, is still quite low. This review compiles information on studies evidencing the impact of HAB toxins on marine birds, with a special focus on the effects of paralytic and amnesic shellfish toxins (PSTs and ASTs). It is mainly centered on studies in which the presence of PSTs and/or ASTs in seabird samples was demonstrated through analyses. The analytical techniques commonly employed, the tissues selected and the adjustments done in protocols for processing seabird matrixes are summarized. Other topics covered include the role of different vectors in the seabird intoxications, information on clinical signs in birds affected by PSTs and ASTs, and multifactorial causes which could aggravate the syndromes. Close collaboration between seabird experts and marine biotoxins researchers is needed to identify and report the potential involvement of HABs and their toxins in the mortality events. Future studies on the PSTs and ASTs pharmacodynamics, together with the establishment of lethal doses in various seabird species, are also necessary. These studies would aid in the selection of the target organs for toxins analyses and in the postmortem intoxication diagnoses.

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He, Chen, Wu, Sun, Ma, Wang, Liu, Chen, and Wang. "Distribution Characteristics and Environmental Control Factors of Lipophilic Marine Algal Toxins in Changjiang Estuary and the Adjacent East China Sea." Toxins 11, no. 10 (October 12, 2019): 596. http://dx.doi.org/10.3390/toxins11100596.

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Marine algal toxins, highly toxic secondary metabolites, have significant influences on coastal ecosystem health and mariculture safety. The occurrence and environmental control factors of lipophilic marine algal toxins (LMATs) in the surface seawater of the Changjiang estuary (CJE) and the adjacent East China Sea (ECS) were investigated. Pectenotoxin-2 (PTX2), okadaic acid (OA), dinophysistoxin-1(DTX1), and gymnodimine (GYM) were detected in the CJE surface seawater in summer, with concentration ranges of not detected (ND)–105.54 ng/L, ND–13.24 ng/L, ND–5.48 ng/L, and ND–12.95 ng/L, respectively. DTX1 (ND–316.15 ng/L), OA (ND–16.13 ng/L), and PTX2 (ND–4.97 ng/L) were detected in the ECS during spring. LMATs formed a unique low-concentration band in the Changjiang diluted water (CJDW) coverage area in the typical large river estuary. PTX2, OA, and DTX1 in seawater were mainly derived from Dinophysis caudate and Dinophysis rotundata, while GYM was suspected to be from Karenia selliformis. Correlation analyses showed that LMAT levels in seawater were positively correlated with dissolved oxygen and salinity, but negatively correlated with temperature and nutrients, indicating that the hydrological condition and nutritional status of seawater and climatic factors exert significant effects on the distribution of LMATs.

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Townhill, Bryony L., Jonathan Tinker, Miranda Jones, Sophie Pitois, Veronique Creach, Stephen D. Simpson, Stephen Dye, Elizabeth Bear, and John K. Pinnegar. "Harmful algal blooms and climate change: exploring future distribution changes." ICES Journal of Marine Science 75, no. 6 (September 11, 2018): 1882–93. http://dx.doi.org/10.1093/icesjms/fsy113.

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Abstract Harmful algae can cause death in fish, shellfish, marine mammals, and humans, via their toxins or from effects associated with their sheer quantity. There are many species, which cause a variety of problems around north-west Europe, and the frequency and distribution of algal blooms have altered in the recent past. Species distribution modelling was used to understand how harmful algal species may respond in the future to climate change, by considering environmental preferences and how these may shift. Most distribution studies to date use low resolution global model outputs. In this study, high resolution, downscaled shelf seas climate projections for the north-west European shelf were nested within lower resolution global projections, to understand how the distribution of harmful algae may change by the mid to end of century. Projections suggest that the habitat of most species (defined by temperature, salinity, depth, and stratification) will shift north this century, with suitability increasing in the central and northern North Sea. An increase in occurrence here might lead to more frequent detrimental blooms if wind, irradiance and nutrient levels are also suitable. Prioritizing monitoring of species in these susceptible areas could help in establishing early-warning systems for aquaculture and health protection schemes.

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Wu, Danni, Junhui Chen, Jiuming Wang, Xiuping He, Ming Xin, and Baodong Wang. "Monitoring and warning of lipophilic marine algal toxins in mariculture zone based on toxin profiles of phytoplankton." Ecotoxicology and Environmental Safety 197 (July 2020): 110647. http://dx.doi.org/10.1016/j.ecoenv.2020.110647.

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Ben-Gigirey, Begoña, Araceli E. Rossignoli, Pilar Riobó, and Francisco Rodríguez. "First Report of Paralytic Shellfish Toxins in Marine Invertebrates and Fish in Spain." Toxins 12, no. 11 (November 19, 2020): 723. http://dx.doi.org/10.3390/toxins12110723.

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A paralytic shellfish poisoning (PSP) episode developed in summer 2018 in the Rías Baixas (Galicia, NW Spain). The outbreak was associated with an unprecedentedly intense and long-lasting harmful algal bloom (HAB) (~one month) caused by the dinoflagellate Alexandrium minutum. Paralytic shellfish toxins (PSTs) were analyzed in extracts of 45 A. minutum strains isolated from the bloom by high-performance liquid chromatography with post-column oxidation and fluorescence detection (HPLC-PCOX-FLD). PSTs were also evaluated in tissues from marine fauna (invertebrates and fish) collected during the episode and in dolphin samples. The analysis of 45 A. minutum strains revealed a toxic profile including GTX1, GTX2, GTX3 and GTX4 toxins. With regard to the marine fauna samples, the highest PSTs levels were quantified in bivalve mollusks, but the toxins were also found in mullets, mackerels, starfish, squids and ascidians. This study reveals the potential accumulation of PSTs in marine invertebrates other than shellfish that could act as vectors in the trophic chain or pose a risk for human consumption. To our knowledge, this is the first time that PSTs are reported in ascidians and starfish from Spain. Moreover, it is the first time that evidence of PSTs in squids is described in Europe.

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Wang, Su-Chun, Fei-Fei Liu, Tian-Yuan Huang, Jin-Lin Fan, Zhi-Yin Gao, and Guang-Zhou Liu. "Effects of Nanoplastics on the Dinoflagellate Amphidinium carterae Hulburt from the Perspectives of Algal Growth, Oxidative Stress and Hemolysin Production." Nanomaterials 11, no. 10 (September 22, 2021): 2471. http://dx.doi.org/10.3390/nano11102471.

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Recently, the effects of nanoplastics (NPs) on aquatic organisms have attracted much attention; however, research on the toxicity of NPs to microalgae has been insufficient. In the present study, the effects of polystyrene nanoplastics (nano-PS, 50 nm) on growth inhibition, chlorophyll content, oxidative stress, and algal toxin production of the marine toxigenic dinoflagellate Amphidinium carterae Hulburt were investigated. Chlorophyll synthesis was promoted by nano-PS on day 2 but was inhibited on day 4; high concentrations of nano-PS (≥50 mg/L) significantly inhibited the growth of A. carterae. Moreover, despite the combined effect of superoxide dismutase (SOD) and glutathione (GSH), high reactive oxygen species (ROS) level and malondialdehyde (MDA) content were still induced by nano-PS (≥50 mg/L), indicating severe lipid peroxidation. In addition, the contents of extracellular and intracellular hemolytic toxins in nano-PS groups were significantly higher than those in control groups on days 2 and 8, except that those of extracellular hemolytic toxins in the 100 mg/L nano-PS group decreased on day 8 because of severe adsorption of hemolytic toxins to the nano-PS. Hence, the effects of nano-PS on A. carterae are closely linked to nano-PS concentration and surface properties and exposure time. These findings provide a deep understanding of the complex effects of NPs on toxigenic microalgae and present valuable data for assessing their environmental risks.

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Khan, Saleha, Nowrin Akter Shaika, and Sunzida Sultana. "Harmful algal blooms in the coastal waters of Bangladesh: an overview." Journal of Aquaculture and Marine Biology 11, no. 3 (November 10, 2022): 105–11. http://dx.doi.org/10.15406/jamb.2022.11.00344.

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Harmful algal blooms (HABs) constitute a global problem, affecting aquatic ecosystems, human health, fisheries and local economies. The Bay of Bengal, along the Bangladesh coast, is exceedingly suffering from pollution or anthropogenic nutrification that influences frequently occurring HAB species. The progression of climate change and eutrophication invigorate HAB trends and responses that in turn affect the respective coastal livelihood and economic growth. Tripos spp., Dinophysis spp., Protoperidinium spp., Chaetoceros spp., and Pseudo-nitzschia spp. are the common bloom-forming HAB species in the coastal waters of Bangladesh. Despite having huge potentiality for regional and global perspectives, the coastal region of Bangladesh remains relatively unexplored compared to other regions in the context of HABs and their pernicious effects. As a result, harmful algal blooms and the accumulation of algal toxins may interrupt fisheries, aquaculture, aquatic ecosystems and public health in the country. Therefore, proper research on the biology and ecology of harmful algae, biotoxins and their relationship with environmental factors need to be adequately understood to minimize their adverse effects on the noted marine resources of the Bay. This review focused on an overview of the HAB related issues – causes of HABs, their occurrences and abundances, associated environmental factors and adverse effects in the coastal zone of Bangladesh.

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Selander, Erik, Julia Kubanek, Mats Hamberg, Mats X. Andersson, Gunnar Cervin, and Henrik Pavia. "Predator lipids induce paralytic shellfish toxins in bloom-forming algae." Proceedings of the National Academy of Sciences 112, no. 20 (April 27, 2015): 6395–400. http://dx.doi.org/10.1073/pnas.1420154112.

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Interactions among microscopic planktonic organisms underpin the functioning of open ocean ecosystems. With few exceptions, these organisms lack advanced eyes and thus rely largely on chemical sensing to perceive their surroundings. However, few of the signaling molecules involved in interactions among marine plankton have been identified. We report a group of eight small molecules released by copepods, the most abundant zooplankton in the sea, which play a central role in food webs and biogeochemical cycles. The compounds, named copepodamides, are polar lipids connecting taurine via an amide to isoprenoid fatty acid conjugate of varying composition. The bloom-forming dinoflagellate Alexandrium minutum responds to pico- to nanomolar concentrations of copepodamides with up to a 20-fold increase in production of paralytic shellfish toxins. Different copepod species exude distinct copepodamide blends that contribute to the species-specific defensive responses observed in phytoplankton. The signaling system described here has far reaching implications for marine ecosystems by redirecting grazing pressure and facilitating the formation of large scale harmful algal blooms.

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Bowers, Emily K., Raphaela Stimmelmayr, Alicia Hendrix, and Kathi A. Lefebvre. "Stability of Saxitoxin in 50% Methanol Fecal Extracts and Raw Feces from Bowhead Whales (Balaena mysticetus)." Marine Drugs 20, no. 9 (August 25, 2022): 547. http://dx.doi.org/10.3390/md20090547.

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In recent decades, harmful algal blooms (HABs) producing paralytic shellfish toxins (including saxitoxin, STX) have become increasingly frequent in the marine waters of Alaska, USA, subjecting Pacific Arctic and subarctic communities and wildlife to increased toxin exposure risks. Research on the risks of HAB toxin exposures to marine mammal health commonly relies on the sampling of marine mammal gastrointestinal (GI) contents to quantify HAB toxins, yet no studies have been published testing the stability of STX in marine mammal GI matrices. An understanding of STX stability in test matrices under storage and handling conditions is imperative to the integrity of toxin quantifications and conclusions drawn thereby. Here, STX stability is characterized in field-collected bowhead whale feces (stored raw in several treatments) and in fecal extracts (50% methanol, MeOH) over multiple time points. Toxin stability, as the percent of initial concentration (T0), was reported for each storage treatment and time point. STX was stable (mean 99% T0) in 50% MeOH extracts over the 8-week study period, and there was no significant difference in STX concentrations quantified in split fecal samples extracted in 80% ethanol (EtOH) and 50% MeOH. STX was also relatively stable in raw fecal material stored in the freezer (mean 94% T0) and the refrigerator (mean 93% T0) up to 8 weeks. STX degraded over time in the room-temperature dark, room-temperature light, and warm treatments to means of 48 ± 1.9, 38 ± 2.8, and 20 ± 0.7% T0, respectively, after 8 weeks (mean ± standard error; SE). Additional opportunistically analyzed samples frozen for ≤4.5 years also showed STX to be relatively stable (mean 97% T0). Mean percent of T0 was measured slightly above 100% in some extracts following some treatments, and (most notably) at some long-term frozen time points, likely due to evaporation from samples causing STX to concentrate, or variability between ELISA plates. Overall, these results suggest that long-term frozen storage of raw fecal samples and the analysis of extracts within 8 weeks of extraction in 50% MeOH is sufficient for obtaining accurate STX quantifications in marine mammal fecal material without concerns about significant degradation.

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Journal articles on the topic 'Marine algal toxins'

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