Health effects of recreational exposure to Moreton Bay, Australia waters during a Lyngbya majuscula bloom

The toxic cosmopolitan cyanobacteria Moorena producens: insights into distribution, ecophysiology and toxicity

Moorena producens is a benthic filamentous cyanobacteria that has been widely documented for its toxicity. This cyanobacterium colonizes both temperate (37%) and tropical (63%) regions, making it a cosmopolitan cyanobacterium with a global distribution. M. producens grows across coral reefs in multiple locations but recurringly blooms in Queensland, Australia. Today, nuisance blooms of M. producens have resulted in major disruptions to recreational activities along coastal areas and are known to cause adverse effects on organism and human health upon contact or ingestion. Specifically, marine organisms such as the green turtle Chelonia mydas and hawksbill turtle Eretmochelys imbricata were fatally poisoned by M. producens after consumption of this cyanobacterium. Reports record a range of effects on human health, from pain and blistering or even death upon ingestion of contaminated seafood. Blooms of M. producens are triggered by influxes of nitrogen, phosphate and iron, from surrounding coastal runoffs or sewage effluents. Additions of these nutrients can result in an increase in growth rate by 4-16 times. Iron bioavailability also plays a crucial role in bloom formation. A total of 231 natural products from 66 groups were identified from M. producens, with the three dominant groups: malyngamides, microcolins and dolastatins. These bioactive secondary metabolites have displayed toxicities against a range of carcinoma cell lines and organisms such as brine shrimp Artemia salina and goldfish Carassius auratus. This review provides a thorough insight to the distribution, ecophysiology and toxicity of M. producens, with reports on bloom events and implications on organism and human health.

Recent advances in nanomaterials-based optical and electrochemical aptasensors for detection of cyanotoxins

The existence of cyanotoxins poses serious threats to human health, it is highly desirable to develop specific and sensitive methods for rapid detection of cyanotoxins in food and water. Due to the distinct advantages of aptamer including high specificity, good stability and easy preparation, various aptamer-based sensors (aptasensors) have been proposed to promote the detection of cyanotoxins. In this review, we summarize recent advance in optical and electrochemical aptasensors for cyanotoxins sensing by integrating with versatile nanomaterials or innovative sensing strategies, such as colorimetric aptasensors, fluorescent aptasensors, surface enhancement Raman spectroscopy-based aptasensors, voltammetric aptasensors, electrochemical impedance spectroscopy-based aptasensors and photoelectrochemical aptasensors. We highlight the accomplishments and advancements of aptasensors with improved performance. Furthermore, the current challenges and future prospects in cyanotoxins detection are discussed from our perspectives, which we hope to provide more ideas for future researchers.

Multimedia distributions and the fate of microcystins from freshwater discharge in the Geum River Estuary, South Korea: Applicability of POCIS for monitoring of microalgal biotoxins

Here, we investigated the characteristics of the environmental multimedia distribution of microcystins (MCs) introduced from freshwater discharge through the estuary dam of the Geum River. In addition, the applicability of a passive sampling device (polar organic chemical integrative sampler, POCIS) for monitoring MCs was evaluated. Surface water, suspended solids (SS), sediments, and oysters were collected from the inner and outer estuary dam. Seven MC variants were analyzed using HPLC-MS/MS. POCIS was deployed at three sites over one week, and MCs were monitored for four weeks from August to September 2019. Before POCIS was deployed in the field, compounds-specific sampling rates of MCs were determined as functions of water temperature (10, 20, and 30 °C), flow rate (0, 0.38, and 0.76 m s^-1), and salinity (0, 15, and 30 psu) in the laboratory. The sampling rates of MCs in POCIS increased significantly with increasing water temperature and flow rate, whereas salinity did not significantly affect the sampling rates between freshwater and saltwater. The MCs in the Geum River Estuary mainly existed as particulate forms (mean: 78%), with relatively low proportions of dissolved forms (mean: 22%), indicating that MCs were mainly contained in cyanobacterial cells. There was no significant correlation among the concentrations of MCs in water, SS, sediments, and oysters. Time-weighted average concentrations of MCs from POCIS were not significantly correlated with the concentrations of MCs in water and oysters. The metabolites of MCs, including MC-LR-GSH, MC-LR-Cys, MC-RR-GSH, and MC-RR-Cys, were detected in oysters (no metabolites were detected in POCIS). Overall, POCIS can be useful for monitoring dissolved MCs in the aquatic ecosystem, particularly in calculating time-weighted average concentrations, but it seems to have limitations in evaluating the contamination status of total MCs, mainly in particulate form.

Distribution of microcystins in environmental multimedia and their bioaccumulation characteristics in marine benthic organisms in the Geum River Estuary, South Korea

Spatio-temporal distributions and bioaccumulation characteristics of freshwater cyanobacterial toxins, such as microcystins (MCs) in the Geum River Estuary, South Korea, were investigated during summer. Environmental multimedia samples (water, suspended particulate matter (SPM), and sediments) and tidal flat organisms (polychaetes, decapods, amphipods, and bivalves) were collected from regions inside and outside of the estuary dam for MCs analysis. Phytoplankton communities in the Geum River (freshwater) and estuarine area (brackish water) were also analyzed in order to understand the relationship with MCs concentrations. Seasonal variation in the structure of phytoplankton communities was detected in the Geum River, with a relatively high density of Cyanophyta in summer. MC concentrations were strongly correlated to water temperature, chlorophyll a, and cyanobacterial density. MC-LR was the most abundant MC variants in environmental samples. Dissolved MCs remained for longer periods and were more widely distributed in the coastal environments compared to particulate MCs. The distribution coefficients between water and SPM (K_d-SPM) and between water and sediments (K_d-sediment) of MCs showed that the phase shift of MCs in the environmental samples occurred in the estuary. K_d-SPM declined from the inside to outside regions of the estuary dam, and was mainly attributed to differences in the half-lives of MCs in dissolved (4.7 d for MC-LR) and particulate phases (0.44-0.52 d for MC-LR). Species-specific bioaccumulation of MCs occurred in tidal flat organisms, with relatively high bioaccumulation factors of MCs being detected in polychaetes and decapods compared to amphipods and bivalves. Overall, this study advances our understanding on the distribution, transport, fate, and bioaccumulation of MCs in estuarine and coastal environments.

Neo-Aplysiatoxin A Isolated from Okinawan Cyanobacterium Moorea Producens

A new aplysiatoxin derivative, neo-aplysiatoxin A (1), along with seven known compounds, neo-debromoaplysiatoxin A (2), dolastatin 3 (3), lyngbic acid (4), malyngamide M (5), hermitamide A (6), (−)-loliolide (7), and (+)-epiloliolide (8), was isolated from the Okinawan cyanobacterium Moorea producens. Their structures were elucidated on the basis of spectroscopic data, including high-resolution mass spectrometry and nuclear magnetic resonance. The compounds were evaluated for cytotoxic and diatom growth inhibition activities.

Economic impact of harmful algal blooms on human health: a systematic review

Harmful algal blooms (HABs) damage human activities and health. While there is wide literature on economic losses, little is known about the economic impact on human health. In this review, we systematically retrieved papers which presented health costs following exposure to HABs. A systematic review was conducted up to January 2019 in databases such as ScienceDirect and PubMed, and 16 studies were selected. Health costs included healthcare and medication expenses, loss of income due to illness, cost of pain and suffering, and cost of death. Two categories of illness (digestive and respiratory) were considered for health costs. For digestive illness cost, we found $86, $1,015 and $12,605, respectively, for mild, moderate and severe cases. For respiratory illness, costs were $86, $1,235 and $14,600, respectively, for mild, moderate and severe cases. We used Quality-Adjusted Life Years (QALYs) to access the loss of well-being due to illness caused by HABs. We found that breathing difficulty causes the most loss of QALYs, especially in children, with a loss of between 0.16 and 0.771 per child. Having gastroenteritis could cause a loss of between 2.2 and 7.1 QALYs per 1,000 children. Misleading symptoms of illness following exposure to HABs could cause bias in health costs estimations.

Natural Products from Cyanobacteria: Focus on Beneficial Activities

Cyanobacteria are photosynthetic microorganisms that colonize diverse environments worldwide, ranging from ocean to freshwaters, soils, and extreme environments. Their adaptation capacities and the diversity of natural products that they synthesize, support cyanobacterial success in colonization of their respective ecological niches. Although cyanobacteria are well-known for their toxin production and their relative deleterious consequences, they also produce a large variety of molecules that exhibit beneficial properties with high potential in various fields (e.g., a synthetic analog of dolastatin 10 is used against Hodgkin's lymphoma). The present review focuses on the beneficial activities of cyanobacterial molecules described so far. Based on an analysis of 670 papers, it appears that more than 90 genera of cyanobacteria have been observed to produce compounds with potentially beneficial activities in which most of them belong to the orders Oscillatoriales, Nostocales, Chroococcales, and Synechococcales. The rest of the cyanobacterial orders (i.e., Pleurocapsales, Chroococcidiopsales, and Gloeobacterales) remain poorly explored in terms of their molecular diversity and relative bioactivity. The diverse cyanobacterial metabolites possessing beneficial bioactivities belong to 10 different chemical classes (alkaloids, depsipeptides, lipopeptides, macrolides/lactones, peptides, terpenes, polysaccharides, lipids, polyketides, and others) that exhibit 14 major kinds of bioactivity. However, no direct relationship between the chemical class and the respective bioactivity of these molecules has been demonstrated. We further selected and specifically described 47 molecule families according to their respective bioactivities and their potential uses in pharmacology, cosmetology, agriculture, or other specific fields of interest. With this up-to-date review, we attempt to present new perspectives for the rational discovery of novel cyanobacterial metabolites with beneficial bioactivity.

Cyanobacteria blooms in water: Italian guidelines to assess and manage the risk associated to bathing and recreational activities

Cyanobacteria thrive in many aquatic environments, where they can produce cyanotoxins with different toxicological profile. Anthropic pressure and climate changes are causing the expansion in terms of time and space of their blooms, increasing the concerns for human health in several exposure scenarios. Here the update of the Italian guidelines for the management of cyanobacterial blooms in bathing water is presented. A risk-based approach has been developed according to the current scientific knowledge on cyanobacteria distribution in the Italian Lakes and on chemical, toxicological and epidemiological aspects of different cyanotoxins, summarized in the first part of the paper. Oral, dermal and inhalation exposure to cyanotoxins, during recreational activities, are individually examined, to develop a framework of thresholds and actions aimed at preventing harmful effects for bathers. Guidelines, also by comparing international guidance values and/or guidelines, provide criteria to plan environmental monitoring activities, health surveillance and public communication systems. Finally the still important scientific gaps and research needs are highlighted.

Effects of two different high-fidelity DNA polymerases on genetic analysis of the cyanobacterial community structure in a subtropical deep freshwater reservoir

The use of molecular methods to investigate the community structure and diversity of microalgae has largely replaced the previous morphological methods that were routinely carried out by microscopy. Different DNA polymerases can lead to bias in PCR amplification and affect the downstream community and diversity analysis. In this study, two clone libraries were constructed with two different DNA polymerases, Q5 high-fidelity DNA polymerase and exTaq polymerase, to compare the differences in their capability to accurately reflect the cyanobacterial community structure and diversity in a subtropical deep freshwater reservoir, Dongzhen reservoir. The results indicated that the two cyanobacterial clone libraries constructed by using Q5 high-fidelity DNA polymerase and exTaq DNA polymerase did not show significant differences, although a slightly higher community diversity was revealed by using Q5 high-fidelity DNA polymerase. It is noteworthy that so far Q5 high-fidelity DNA polymerase was the first time to be employed in the genetic analysis of cyanobacterial community. And it is for the first time that the cyanobacterial community structure in Dongzhen reservoir was analyzed using molecular methods. Phylogenetic analysis revealed that most of the clones belonged to Cyanophyta and chloroplast, among which Cyanobium sp. Suigetsu-CR5 made up the largest fraction of cyanobacteria in winter.

A Prospective Study of Marine Phytoplankton and Reported Illness Among Recreational Beachgoers in Puerto Rico, 2009

BACKGROUND

Blooms of marine phytoplankton may adversely affect human health. The potential public health impact of low-level exposures is not well established, and few prospective cohort studies of recreational exposures to marine phytoplankton have been conducted.

OBJECTIVE

We evaluated the association between phytoplankton cell counts and subsequent illness among recreational beachgoers.

METHODS

We recruited beachgoers at Boquerón Beach, Puerto Rico, during the summer of 2009. We conducted interviews at three time points to assess baseline health, water activities, and subsequent illness. Daily water samples were quantitatively assayed for phytoplankton cell count. Logistic regression models, adjusted for age and sex, were used to assess the association between exposure to three categories of phytoplankton concentration and subsequent illness.

RESULTS

During 26 study days, 15,726 individuals successfully completed all three interviews. Daily total phytoplankton cell counts ranged from 346 to 2,012 cells/mL (median, 712 cells/mL). The category with the highest (≥ 75th percentile) total phytoplankton cell count was associated with eye irritation [adjusted odds ratio (OR) = 1.30; 95% confidence interval (CI): 1.01, 1.66], rash (OR = 1.27; 95% CI: 1.02, 1.57), and earache (OR = 1.25; 95% CI: 0.88, 1.77). In phytoplankton group-specific analyses, the category with the highest Cyanobacteria counts was associated with respiratory illness (OR = 1.37; 95% CI: 1.12, 1.67), rash (OR = 1.32; 95% CI: 1.05, 1.66), eye irritation (OR = 1.25; 95% CI: 0.97, 1.62), and earache (OR = 1.35; 95% CI: 0.95, 1.93).

CONCLUSIONS

We found associations between recreational exposure to marine phytoplankton and reports of eye irritation, respiratory illness, and rash. We also found that associations varied by phytoplankton group, with Cyanobacteria having the strongest and most consistent associations.

CITATION

Lin CJ, Wade TJ, Sams EA, Dufour AP, Chapman AD, Hilborn ED. 2016. A prospective study of marine phytoplankton and reported illness among recreational beachgoers in Puerto Rico, 2009. Environ Health Perspect 124:477-483; http://dx.doi.org/10.1289/ehp.1409558.

Kalkitoxin inhibits angiogenesis, disrupts cellular hypoxic signaling, and blocks mitochondrial electron transport in tumor cells

The biologically active lipopeptide kalkitoxin was previously isolated from the marine cyanobacterium Moorea producens (Lyngbya majuscula). Kalkitoxin exhibited N-methyl-D-aspartate (NMDA)-mediated neurotoxicity and acted as an inhibitory ligand for voltage-sensitive sodium channels in cultured rat cerebellar granule neurons. Subsequent studies revealed that kalkitoxin generated a delayed form of colon tumor cell cytotoxicity in 7-day clonogenic cell survival assays. Cell line- and exposure time-dependent cytostatic/cytotoxic effects were previously observed with mitochondria-targeted inhibitors of hypoxia-inducible factor-1 (HIF-1). The transcription factor HIF-1 functions as a key regulator of oxygen homeostasis. Therefore, we investigated the ability of kalkitoxin to inhibit hypoxic signaling in human tumor cell lines. Kalkitoxin potently and selectively inhibited hypoxia-induced activation of HIF-1 in T47D breast tumor cells (IC50 5.6 nM). Mechanistic studies revealed that kalkitoxin inhibits HIF-1 activation by suppressing mitochondrial oxygen consumption at electron transport chain (ETC) complex I (NADH-ubiquinone oxidoreductase). Further studies indicate that kalkitoxin targets tumor angiogenesis by blocking the induction of angiogenic factors (i.e., VEGF) in tumor cells.

Involvement of JNK and caspase activation in hoiamide A-induced neurotoxicity in neocortical neurons

The frequent occurrence of Moorea producens (formerly Lyngbya majuscula) blooms has been associated with adverse effects on human health. Hoiamide A is a structurally unique cyclic depsipeptide isolated from an assemblage of the marine cyanobacteria M. producens and Phormidiumgracile. We examined the influence of hoiamide A on neurite outgrowth in neocortical neurons and found that it suppressed neurite outgrowth with an IC₅₀ value of 4.89 nM. Further study demonstrated that hoiamide A stimulated lactic acid dehydrogenase (LDH) efflux, nuclear condensation and caspase-3 activity with EC₅₀ values of 3.66, 2.55 and 4.33 nM, respectively. These data indicated that hoiamide A triggered a unique neuronal death profile that involves both necrotic and apoptotic mechanisms. The similar potencies and similar time-response relationships between LDH efflux and caspase-3 activation/nuclear condensation suggested that both necrosis and apoptosis may derive from interaction with a common molecular target. The broad-spectrum caspase inhibitor, Z-VAD-FMK completely inhibited hoiamide A-induced neurotoxicity. Additionally, hoiamide A stimulated JNK phosphorylation, and a JNK inhibitor attenuated hoiamide A-induced neurotoxicity. Collectively, these data demonstrate that hoiamide A-induced neuronal death requires both JNK and caspase signaling pathways. The potent neurotoxicity and unique neuronal cell death profile of hoiamide A represents a novel neurotoxic chemotype from marine cyanobacteria.

Mitigating harmful cyanobacterial blooms in a human- and climatically-impacted world

Bloom-forming harmful cyanobacteria (CyanoHABs) are harmful from environmental, ecological and human health perspectives by outcompeting beneficial phytoplankton, creating low oxygen conditions (hypoxia, anoxia), and by producing cyanotoxins. Cyanobacterial genera exhibit optimal growth rates and bloom potentials at relatively high water temperatures; hence, global warming plays a key role in their expansion and persistence. CyanoHABs are regulated by synergistic effects of nutrient (nitrogen:N and phosphorus:P) supplies, light, temperature, vertical stratification, water residence times, and biotic interactions. In most instances, nutrient control strategies should focus on reducing both N and P inputs. Strategies based on physical, chemical (nutrient) and biological manipulations can be effective in reducing CyanoHABs; however, these strategies are largely confined to relatively small systems, and some are prone to ecological and environmental drawbacks, including enhancing release of cyanotoxins, disruption of planktonic and benthic communities and fisheries habitat. All strategies should consider and be adaptive to climatic variability and change in order to be effective for long-term control of CyanoHABs. Rising temperatures and greater hydrologic variability will increase growth rates and alter critical nutrient thresholds for CyanoHAB development; thus, nutrient reductions for bloom control may need to be more aggressively pursued in response to climatic changes globally.

Toxic alkaloids in Lyngbya majuscula and related tropical marine cyanobacteria

The cyanobacterium Lyngbya majuscula is found in the littoral zone and to a depth of 30m in tropical, subtropical and temperate regions across the globe, as well as being an important contributor to coral reef ecosystems. This cyanobacterium produces a range of chemicals that may contribute to a variety of negative health outcomes including skin, eye and respiratory irritation. The toxic compounds, lyngbyatoxin A and debromoaplysiatoxin, have been implicated in acute dermatologic reactions in human swimmers, and experiments involving these two toxins show the formation of acute dermal lesions. We explore the reported distribution and health implications of L. majuscula, with reference to factors affecting bloom frequency. The likely implications of climate change upon the distribution of the organism, and frequency of blooms are also described.

State of knowledge and concerns on cyanobacterial blooms and cyanotoxins

Cyanobacteria are ubiquitous microorganisms considered as important contributors to the formation of Earth's atmosphere and nitrogen fixation. However, they are also frequently associated with toxic blooms. Indeed, the wide range of hepatotoxins, neurotoxins and dermatotoxins synthesized by these bacteria is a growing environmental and public health concern. This paper provides a state of the art on the occurrence and management of harmful cyanobacterial blooms in surface and drinking water, including economic impacts and research needs. Cyanobacterial blooms usually occur according to a combination of environmental factors e.g., nutrient concentration, water temperature, light intensity, salinity, water movement, stagnation and residence time, as well as several other variables. These environmental variables, in turn, have promoted the evolution and biosynthesis of strain-specific, gene-controlled metabolites (cyanotoxins) that are often harmful to aquatic and terrestrial life, including humans. Cyanotoxins are primarily produced intracellularly during the exponential growth phase. Release of toxins into water can occur during cell death or senescence but can also be due to evolutionary-derived or environmentally-mediated circumstances such as allelopathy or relatively sudden nutrient limitation. Consequently, when cyanobacterial blooms occur in drinking water resources, treatment has to remove both cyanobacteria (avoiding cell lysis and subsequent toxin release) and aqueous cyanotoxins previously released. Cells are usually removed with limited lysis by physical processes such as clarification or membrane filtration. However, aqueous toxins are usually removed by both physical retention, through adsorption on activated carbon or reverse osmosis, and chemical oxidation, through ozonation or chlorination. While the efficient oxidation of the more common cyanotoxins (microcystin, cylindrospermopsin, anatoxin and saxitoxin) has been extensively reported, the chemical and toxicological characterization of their by-products requires further investigation. In addition, future research should also investigate the removal of poorly considered cyanotoxins (β-methylamino-alanine, lyngbyatoxin or aplysiatoxin) as well as the economic impact of blooms.

Harmful cyanobacterial blooms: causes, consequences, and controls

Cyanobacteria are the Earth's oldest oxygenic photoautotrophs and have had major impacts on shaping its biosphere. Their long evolutionary history (≈ 3.5 by) has enabled them to adapt to geochemical and climatic changes, and more recently anthropogenic modifications of aquatic environments, including nutrient over-enrichment (eutrophication), water diversions, withdrawals, and salinization. Many cyanobacterial genera exhibit optimal growth rates and bloom potentials at relatively high water temperatures; hence global warming plays a key role in their expansion and persistence. Bloom-forming cyanobacterial taxa can be harmful from environmental, organismal, and human health perspectives by outcompeting beneficial phytoplankton, depleting oxygen upon bloom senescence, and producing a variety of toxic secondary metabolites (e.g., cyanotoxins). How environmental factors impact cyanotoxin production is the subject of ongoing research, but nutrient (N, P and trace metals) supply rates, light, temperature, oxidative stressors, interactions with other biota (bacteria, viruses and animal grazers), and most likely, the combined effects of these factors are all involved. Accordingly, strategies aimed at controlling and mitigating harmful blooms have focused on manipulating these dynamic factors. The applicability and feasibility of various controls and management approaches is discussed for natural waters and drinking water supplies. Strategies based on physical, chemical, and biological manipulations of specific factors show promise; however, a key underlying approach that should be considered in almost all instances is nutrient (both N and P) input reductions; which have been shown to effectively reduce cyanobacterial biomass, and therefore limit health risks and frequencies of hypoxic events.

Climate change: links to global expansion of harmful cyanobacteria

Cyanobacteria are the Earth's oldest (∼3.5 bya) oxygen evolving organisms, and they have had major impacts on shaping our modern-day biosphere. Conversely, biospheric environmental perturbations, including nutrient enrichment and climatic changes (e.g. global warming, hydrologic changes, increased frequencies and intensities of tropical cyclones, more intense and persistent droughts), strongly affect cyanobacterial growth and bloom potentials in freshwater and marine ecosystems. We examined human and climatic controls on harmful (toxic, hypoxia-generating, food web disrupting) bloom-forming cyanobacteria (CyanoHABs) along the freshwater to marine continuum. These changes may act synergistically to promote cyanobacterial dominance and persistence. This synergy is a formidable challenge to water quality, water supply and fisheries managers, because bloom potentials and controls may be altered in response to contemporaneous changes in thermal and hydrologic regimes. In inland waters, hydrologic modifications, including enhanced vertical mixing and, if water supplies permit, increased flushing (reducing residence time) will likely be needed in systems where nutrient input reductions are neither feasible nor possible. Successful control of CyanoHABs by grazers is unlikely except in specific cases. Overall, stricter nutrient management will likely be the most feasible and practical approach to long-term CyanoHAB control in a warmer, stormier and more extreme world.

An Integrated Bayesian Network approach to Lyngbya majuscula bloom initiation

Blooms of the cyanobacteria Lyngbya majuscula have occurred for decades around the world. However, with the increase in size and frequency of these blooms, coupled with the toxicity of such algae and their increased biomass, they have become substantial environmental and health issues. It is therefore imperative to develop a better understanding of the scientific and management factors impacting on Lyngbya bloom initiation. This paper suggests an Integrated Bayesian Network (IBN) approach that facilitates the merger of the research being conducted by various parties on Lyngbya. Pivotal to this approach are two Bayesian networks modelling the management and scientific factors of bloom initiation. The research found that Bayesian Networks (BN) and specifically Object Oriented BNs (OOBN) and Dynamic OOBNs facilitate an integrated approach to modelling ecological issues of concern. The merger of multiple models which explore different aspects of the problem through an IBN approach can apply to many multi-faceted environmental problems.

Dermatitis associated with exposure to a marine cyanobacterium during recreational water exposure

Background

Anecdotal evidence reported an outbreak of symptoms on Fraser Island during the late 1990s similar to those expected from exposure to dermotoxins found in the cyanobacterium L. majuscula. This coincided with the presence of a bloom of L. majuscula.

Methods

Records from the Fraser Island National Parks First aid station were examined. Information on cyanobacterial blooms at Fraser Island were obtained from Queensland National Parks rangers.

Results

Examination of first aid records from Fraser Island revealed an outbreak of symptoms predominantly in January and February 1998.

Conclusion

During a bloom of L. majuscula there were numerous reports of symptoms that could be attributed to dermotoxins found in L. majuscula. The other four years examined had no L. majuscula blooms and the number of L. majuscula symptoms was much reduced. These cases comprised a high percentage of the cases treated at the first aid station.