Download or read book Spatial and Temporal Dynamics of Cyanobacteria and Microcystins in Freshwater Systems written by Som Cit Si Nang and published by . This book was released on 2012 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: [Truncated abstract] Excessive growth of cyanobacteria, commonly known as cyanobacterial blooms, appear to be increasing in magnitude and frequency worldwide, thus posing a serious threat to the safety and security of water resources. With the increasing global water stress, there is a need for effective management of cyanobacterial blooms in water bodies. So far, it has been a great challenge to mitigate and assess public health risks associated with cyanobacterial blooms due to difficulty in predicting the level of cyanobacterial biomass and microcystin concentrations in water bodies. Moreover, the effectiveness of the current bloom prevention and risk assessment strategies depend upon the understanding of the dynamics of cyanobacteria and microcystin under natural conditions. Thus, this research aims to: i) assess the variability of the relationship between cyanobacterial biomass and microcystin concentration, which is currently used to assess the risk to human and ecosystems health; ii) determine the environmental drivers of the dynamics of cyanobacterial dominance and microcystin concentration and assess site specificity of the environmental drivers; and iii) investigate how changes in the structure of phytoplankton community and cyanobacterial composition in response to nutrient concentration affect the dynamics of microcystin concentration. The results contained in this thesis revealed that the biomass-toxin relationship is a function of spatiotemporal patterns that affect cyanobacterial and microcystin dynamics. The correlation between the biomass and toxin is weak and site-specific, and large changes in total microcystin concentrations occur even at stable cyanobacterial biomass concentrations. This could pose a significant threat to the risk assessment associated with microcystin contamination in water bodies...
Download or read book Spatial and Temporal Dynamics of Cyanotoxins and Their Relation to Other Water Quality Variables in Upper Klamath Lake Oregon 2007 09 written by Sara L. Caldwell Eldridge and published by CreateSpace. This book was released on 2014-07-11 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phytoplankton blooms dominated by cyanobacteria that occur annually in hypereutrophic Upper Klamath Lake, Oregon, produce microcystins at concentrations that may contribute to the decline in populations of endangered Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers. During 2007–09, water samples were collected from Upper Klamath Lake to determine the presence and concentrations of microcystins and cylindrospermopsins and to relate the spatial and temporal occurrences of microcystins to water quality and other environmental variables.
Download or read book Spatial and Temporal Variation in Cyanobacterial Population Dynamics and Microcystin Production in Eutrophic Lakes written by and published by . This book was released on 2013 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Toxic cyanobacterial blooms threaten freshwaters worldwide. We have learned much about the environmental factors promoting cyanobacterial success: high growth rates in increased water temperatures, predator avoidance, an ability to store nitrogen (N) and phosphorus (P), positive buoyancy, high affinity for inorganic carbon (C) and efficiency for converting bicarbonate to carbon dioxide (CO2), and the ability of some to fix dinitrogen (N2). However, the physiological and ecological role of cyanotoxins eludes us. Furthermore, complex population dynamics of toxic and non-toxic cyanobacterial strains confounds many ecosystem-based studies. Thus, our research has focused on describing spatial and temporal cyanobacterial population dynamics and cyanotoxin production in eutrophic lakes. Our results indicate that vertical heterogeneity in lakes is important for partitioning individual cyanobacterial taxa within the photic zone on short time scales (hourly-daily). However, on the time-scales that toxic blooms occur (days-weeks), physics likely plays a larger role in distributing cyanobacterial biomass and toxins throughout the epilimnion. Similarly, horizontal heterogeneity in lakes can be extremely patchy. We observed on daily time-scales, cyanotoxins could vary by orders of magnitude in different parts of the lake. Thus, toxic blooms are not evenly distributed horizontally or vertically in lakes on short time scales, but were also not significantly different beyond several days. Conversely, cyanobacterial communities and toxin concentrations changed significantly over the course of the open water season. Intra-annual changes in temperature, lake stratification, and nutrient concentrations had a profound impact on cyanobacterial community composition and measured toxin concentrations. In particular, inorganic nitrogen drawdown during stratification resulted in large N2 fixing Aphanizomenon blooms. Shortly thereafter, Microcystis abundance and microcystin concentrations increased significantly. Aphanizomenon and Microcystis were both abundant in the fall, but toxin concentrations decreased. Three Microcystis genotypes were abundant at different times of the year, suggesting they occupy different niches. We proposed that microcystin production was caused by N stress, particularly the rapid drawdown of ammonium, and present a metabolic model for regulation of microcystin synthesis in Microcystis. Together, these results have implications for lake management, public health, and modeling toxin production in eutrophic lakes.
Download or read book Cyanobacterial Harmful Algal Blooms State of the Science and Research Needs written by H. Kenneth Hudnell and published by Springer Science & Business Media. This book was released on 2008-03-13 with total page 955 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the ever-increasing incidence of harmful cyanobacterial algal blooms, this monograph has added urgency and will be essential reading for all sorts of researchers, from neuroscientists to cancer research specialists. The volume contains the proceedings of the 2005 International Symposium on Cyanobacterial Harmful Algal Blooms, and has been edited by H. Kenneth Hudnell, of the US Environmental Protection Agency. It contains much of the most recent research into the subject.
Download or read book Environmental Fluid Dynamics written by Jorg Imberger and published by Academic Press. This book was released on 2012-09-06 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: A broad cross-section of scientists working in aquatic environments will enjoy this treatment of environmental fluid dynamics, a foundation for elucidating the importance of hydrodynamics and hydrology in the regulation of energy.
Download or read book A Manual of Chemical Biological Methods for Seawater Analysis written by Timothy R. Parsons and published by Elsevier. This book was released on 2013-10-22 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to the quantitative analysis of seawater, describing in detail biological and chemical techniques, which are considered to be amongst those most often used by biological oceanographers. The manual provides complete instructions for the addition of reagents and calculation of results with reference material for each method so that the original texts can be consulted if necessary. In general, the techniques require a minimum of prior professional training and methods needing very expensive equipment have been avoided.
Download or read book Microcystin Production and the Dominance of Toxigenic Strains of Cyanobacteria in Lake and Culture Studies written by Susan LeBlanc Renaud and published by . This book was released on 2009 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific Investigations Report written by Sharon E. Kroening and published by . This book was released on 2004 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Climate Change and Marine and Freshwater Toxins written by Luis M. Botana and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-12-16 with total page 669 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasingly widespread production of toxins by marine and freshwater microalgae raises serious concerns regarding seafood and drinking water safety. This book compiles studies on the influence of climate change on the spreading of toxin-producing species in aquatic systems. The chemistry and biology of toxin production is revised and an outlook on control and prevention of the toxins' impact on human and animal health is given.
Download or read book Cyanotoxins written by Ingrid Chorus and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: Toxic cyanobacteria are increasingly recognised as a potential hazard in water for human use. The recent availability of methods for quantitative screening is leading to a surge of research on their occurrence. This book presents a novel compilation of extensive screening results showing the cyanotoxin levels that may be expected when certain taxa dominate. These results indicate cyanotoxins to be the most widespread among the chemicals of concern in water used for drinking and recreation. It further combines field data with results from laboratory culture experiments to suggest a unifying view of how environmental factors control the cyanotoxin levels in natural waters. A practical section is dedicated to the exposure of humans through drinking-water and recreation.
Download or read book Physiological and molecular ecology of aquatic cyanobacteria written by Anton F Post and published by Frontiers Media SA. This book was released on 2015-03-26 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cyanobacteria inhabit every illuminated environment on Earth, from polar lakes to desert crusts and through their phototrophic metabolism play essential roles in global geochemical cycles. With the discovery of marine Synechococcus and Prochlorococcus almost 30 years ago, cyanobacteria have now earned their place as dominant primary producers contributing over 25 percent of global photosynthesis. Their global abundance is now explained from the coexistence of ecotypes that occupy different niches along spatial and temporal gradients. New ecotypes of Synechococcus have been identified as abundant components of microbial communities in freshwater environments and marginal seas. Extensive comparative genomics of marine and freshwater picocyanobacteria have begun to unmask adaptations to light and nutrient (N, P, Fe) limitation that these diverse environments present. Novel types of cyanobacterial diazotrophy input new N and structure microbial communities in the open sea. Current challenges include the understanding of the interactions between marine cyanobacteria and other microbes in their immediate community. In contrast, mesotrophic and eutrophic environments such as the Laurentian Great Lakes have been increasingly affected by nuisance and toxic cyanobacterial blooms that have yielded severe declines in water quality. Factors promoting bloom formation and the functional roles of toxins are important issues being addressed today.
Download or read book Harmful Cyanobacteria written by Jef Huisman and published by Springer Science & Business Media. This book was released on 2005-06-15 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: This outstanding volume provides an up-to-date overview of the advances in our knowledge of harmful cyanobacteria. An essential reference for all scientists and environmental professionals interested in cyanobacterial ecology and water management.
Download or read book Cyanobacterial Toxins of Drinking Water Supplies written by Ian Robert Falconer and published by CRC Press. This book was released on 2004-12-20 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contamination of both drinking and recreational water supplies by cyanobacteria is increasingly a cause for concern worldwide. While contamination causes livestock deaths with relative frequency, acute poisoning is rare in humans. However, there is growing apprehension over the possible role of cylindrospermopsins and microcystins in gastrointe
Download or read book Toxic Cyanobacteria in Water written by Ingrid Chorus and published by CRC Press. This book was released on 2021-03-08 with total page 701 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cyanobacterial toxins are among the hazardous substances most widely found in water. They occur naturally, but concentrations hazardous to human health are usually due to human activity. Therefore, to protect human health, managing lakes, reservoirs and rivers to prevent cyanobacterial blooms is critical. This second edition of Toxic Cyanobacteria in Water presents the current state of knowledge on the occurrence of cyanobacteria and cyanotoxins as well as their impacts on health through water-related exposure pathways, chiefly drinking-water and recreational activity. It provides scientific and technical background information to support hazard identification, assessment and prioritisation of the risks posed by cyanotoxins, and it outlines approaches for their management at each step of the water-use system. It sets out key practical considerations for developing management strategies, implementing efficient measures and designing monitoring programmes. This enables stakeholders to evaluate whether there is a health risk from toxic cyanobacteria and to mitigate it with appropriate measures. This book is intended for those working on toxic cyanobacteria with a specific focus on public health protection. It intends to empower professionals from different disciplines to communicate and cooperate for sustainable management of toxic cyanobacteria, including public health workers, ecologists, academics, and catchment and waterbody managers. Ingrid Chorus headed the department for Drinking-Water and Swimming-Pool Hygiene at the German Environment Agency. Martin Welker is a limnologist and microbiologist, currently with bioMérieux in Lyon, France.
Download or read book Toxic Cyanobacteria in Water written by Ingrid Chorus and published by CRC Press. This book was released on 1999-02-11 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cyanobacteria and their toxins are an increasing global public health menace. Most recently, problems have been experienced in Australia, the United States and, due to drought and increasing water scarcity, pose a severe threat in the U.K. With an international range of contributors, all leading experts in their fields, Toxic Cyanobacteria in Water examines the increasing need to protect drinking water and water resources from the hazards of Cyanobacteria and their impact on health. Written and edited by a World Health Organization working group, Toxic Cyanobacteria in Water is an operational handbook in a practical, assessible style. Toxic Cyanobacteria in Water will be invaluable to environmental health officers, professionals in the fields of water supply, public health, fresh water ecology and education, national and international organizations, special interest groups, post-graduate students and utilities responsible for managing drinking water supplies.
Download or read book Toxic Microcystis written by Mariyo F. Watanabe and published by CRC Press. This book was released on 1995-11-21 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses toxic Microcystis and the toxins from various viewpoints such as classification, cultivation, occurrences in lakes, and relations to zooplankton. The text presents new information on the chemistry, analytical chemistry, toxicology, molecular modeling, and liver tumor promotion of the toxins. Microcystis species are described in relation to morphological features, allozyme genotype, and toxin content. Seasonal changes of Microcystis population are described with special references to toxic species and composition of the toxins. Chemical characteristics of microcystins are reviewed and the process for identification of microcystins is described.
Download or read book Abstracts from the Conference on Great Lakes Research written by and published by . This book was released on 2007 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
