This book describes the present state of knowledge regarding the impact of cyanobacteria on health through the use of water. It considers aspects of risk management and details the information needed for protecting drinking water sources and recreational water bodies from the health hazards caused by cyanobacteria and their toxins. It also outlines the state of knowledge regarding the principal considerations in the design of programmes and studies for monitoring water resources and supplies and describes the approaches and procedures used.
The development of this publication was guided by the recommendations of several expert meetings concerning drinking water (Geneva, December 1995; Bad Elster, June
1996) and recreational water (Bad Elster, June 1996; St Helier, May 1997). An expert meeting in Bad Elster, April 1997, critically reviewed the literature concerning the toxicity of cyanotoxins and developed the scope and content of this book. A draft manuscript was reviewed at an editorial meeting in November 1997, and a further draft was
reviewed by the working group responsible for updating the Guidelines for Drinkingwater Quality in March 1998.

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Toxic cyanobacteria in water: a guide to their public health consequences, monitoring and management.

Emerging recognition of two fundamental errors under-pinning past polices for natural resource issues heralds awareness of the need for a worldwide fundamental change in thinking and in practice of environmental management. The first error has been an implicit assumption that ecosystem responses to human use are linear, predictable and controllable. The second has been an assumption that human and natural systems can be treated independently. However, evidence that has been accumulating in diverse regions all over the world suggests that natural and social systems behave in nonlinear ways, exhibit marked thresholds in their dynamics, and that social-ecological systems act as strongly coupled, complex and evolving integrated systems. This article is a summary of a report prepared on behalf of the Environmental Advisory Council to the Swedish Government, as input to the process of the World Summit on Sustainable Development (WSSD) in Johannesburg, South Africa in 26 August 4 September 2002. We use the concept of resilience—the capacity to buffer change, learn and develop—as a framework for understanding how to sustain and enhance adaptive capacity in a complex world of rapid transformations. Two useful tools for resilience-building in social-ecological systems are structured scenarios and active adaptive management. These tools require and facilitate a social context with flexible and open institutions and multi-level governance systems that allow for learning and increase adaptive capacity without foreclosing future development options.

https://bioone.org/journals/AMBIO-A-Journal-of-the-Human-Environment/volume-31/issue-5/0044-7447-31.5.437/Resilience-and-Sustainable-Development--Building-Adaptive-Capacity-in-a/10.1579/0044-7447-31.5.437.pdf

Resilience and sustainable development: building adaptive capacity in a world of transformations

Although algal blooms, including those considered toxic or harmful, can be natural phenomena, the nature of the global problem of harmful algal blooms (HABs) has expanded both in extent and its public perception over the last several decades. Of concern, especially for resource managers, is the potential relationship between HABs and the accelerated eutrophication of coastal waters from human activities. We address current insights into the relationships between HABs and eutrophication, focusing on sources of nutrients, known effects of nutrient loading and reduction, new understanding of pathways of nutrient acquisition among HAB species, and relationships between nutrients and toxic algae. Through specific, regional, and global examples of these various relationships, we offer both an assessment of the state of understanding, and the uncertainties that require future research efforts. The sources of nutrients poten- tially stimulating algal blooms include sewage, atmospheric deposition, groundwater flow, as well as agricultural and aquaculture runoff and discharge. On a global basis, strong correlations have been demonstrated between total phos- phorus inputs and phytoplankton production in freshwaters, and between total nitrogen input and phytoplankton pro- duction in estuarine and marine waters. There are also numerous examples in geographic regions ranging from the largest and second largest U.S. mainland estuaries (Chesapeake Bay and the Albemarle-Pamlico Estuarine System), to the Inland Sea of Japan, the Black Sea, and Chinese coastal waters, where increases in nutrient loading have been linked with the development of large biomass blooms, leading to anoxia and even toxic or harmful impacts on fisheries re- sources, ecosystems, and human health or recreation. Many of these regions have witnessed reductions in phytoplankton biomass (as chlorophyll a) or HAB incidence when nutrient controls were put in place. Shifts in species composition have often been attributed to changes in nutrient supply ratios, primarily N:P or N:Si. Recently this concept has been extended to include organic forms of nutrients, and an elevation in the ratio of dissolved organic carbon to dissolved organic nitrogen (DOC:DON) has been observed during several recent blooms. The physiological strategies by which different groups of species acquire their nutrients have become better understood, and alternate modes of nutrition such as heterotrophy and mixotrophy are now recognized as common among HAB species. Despite our increased un- derstanding of the pathways by which nutrients are delivered to ecosystems and the pathways by which they are assimilated differentially by different groups of species, the relationships between nutrient delivery and the development of blooms and their potential toxicity or harmfulness remain poorly understood. Many factors such as algal species presence/ abundance, degree of flushing or water exchange, weather conditions, and presence and abundance of grazers contribute to the success of a given species at a given point in time. Similar nutrient loads do not have the same impact in different environments or in the same environment at different points in time. Eutrophication is one of several mechanisms by which harmful algae appear to be increasing in extent and duration in many locations. Although important, it is not the only explanation for blooms or toxic outbreaks. Nutrient enrichment has been strongly linked to stimulation of some harmful species, but for others it has not been an apparent contributing factor. The overall effect of nutrient over- enrichment on harmful algal species is clearly species specific.

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Harmful Algal Blooms and Eutrophication: Nutrient Sources, Composition, and Consequences

Communities of microscopic plant life, or phytoplankton, dominate the Earth's aquatic ecosystems. This important new book by Colin Reynolds covers the adaptations, physiology and population dynamics of phytoplankton communities in lakes and rivers and oceans. It provides basic information on composition, morphology and physiology of the main phyletic groups represented in marine and freshwater systems and in addition reviews recent advances in community ecology, developing an appreciation of assembly processes, co-existence and competition, disturbance and diversity. Although focussed on one group of organisms, the book develops many concepts relevant to ecology in the broadest sense, and as such will appeal to graduate students and researchers in ecology, limnology and oceanography.

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The Ecology of Phytoplankton

The rise of harmful cyanobacteria blooms: The potential roles of eutrophication and climate change

Concentrations of particulate and dissolved cylindrospermopsin in 21 Aphanizomenon-dominated temperate lakes.

Throughout their lifespan, humans are exposed to many chemical substances, both beneficial and harmful. It is not possible to eliminate exposure to all toxins in our environment. Of the harmful chemicals, some are anthropogenic and others occur naturally. Although cyanotoxins occur naturally, their presence and abundance are, to a large extent, influenced and increased by human action. The extent to which cyanotoxins pose a human health risk depends on human exposure to these toxins. Reducing human exposure to cyanotoxins may be achieved either through preventing the occurrence of hazardous cell densities of toxic cyanobacteria, or by placing barriers (such as drinking water treatment or bathing restrictions) that would reduce human exposure to the cyanobacterial hazard.

Safe levels and safe practices

Current approaches to cyanotoxin risk assessment and risk management around the globe.

In 1995 and 1996 a total of 55 German water bodies with different trophic states were investigated for the presence of potentially microcystin-producing cyanobacteria. The seston biomass of over 500 samples was analyzed by HPLC to assess microcystin content. The highest microcystin content per dry weight was found when Planktothrix rubescens was dominant, followed by Planktothrix agardhii and Microcystis spp. The microcystin to chlorophyll-a ratio mostly varied between 0.1 and 0.5, with maxima of 1–2. In over 70% of the samples from pelagic water, particulate microcystin concentrations were below 10 μg L−1. By contrast, spatial and temporal concentrations varied by 4 orders of magnitude (2–25,000 μg L−1) at bathing sites in 1997 during a mass development of Microcystis spp. The seasonal peak of development of Microcystis spp. occurred from June to September and of Planktothrix agardhii from September to November. Planktothrix rubescens, however, was almost perennial. The seasonal levels of these cyanobacteria were clearly reflected by microcystin concentrations in the water bodies. ©1999 John Wiley & Sons, Inc. Environ Toxicol 14: 13–22, 1999

Microcystins (hepatotoxic heptapeptides) in german fresh water bodies

Fifteen microcystins (MC) were isolated from field samples dominated by Microcystis spp., Planktothrix agardhii or Planktothrix rubescens using reversed phase high-performance liquid chromatography (HPLC). Characterization of microcystins was performed with amino acid analysis followed by fast atom bombardment mass spectrometry (FABMS), and/or matrix assisted laser desorption ionization mass spectrometry (MALDI-TOF MS). In blooms of Microcystis spp. major microcystins were usually MC-RR, MC-YR and MC-LR, while in one strain [D-Asp 3 ] MC-LR and [D-Asp 3 ] MC-RR were also quantitatively abundant. The main microcystins found in field samples of Planktothrix agardhii were [D-Asp 3 ] MC-RR followed by [D-Asp 3 ] MC-LR and a [D-Asp 3 ] variant of MC-HtyR. Planktothrix agardhii strain HUB 076 produced [D-Asp 3 ] MC-RR as a single component. In all Planktothrix rubescens populations [D-Asp 3 , Dhb 7 ] MC-RR was the most abundant microcystin. Furthermore we found that microcystin composition in field populations of single species scarcely changed over time as long as dominance of this species persisted.

Ingrid Chorus

Papers

Concentrations of particulate and dissolved cylindrospermopsin in 21 Aphanizomenon-dominated temperate lakes.

Safe levels and safe practices

Current approaches to cyanotoxin risk assessment and risk management around the globe.

Microcystins (hepatotoxic heptapeptides) in german fresh water bodies

Characterization and diversity of microcystins in natural blooms and strains of the genera Microcystis and Planktothrix from German freshwaters