The Impacts Of Anthropogenic Activity And Climate Change On The Formation Of Harmful Algal Blooms Habs And Its Ecological Consequence

Harmful algal blooms (HABs) - blooms that cause fish kills, contaminate seafood with toxins, or cause human or ecological health impacts and harm to local economies - are occurring more often, in more places and lasting longer than in past decades. This expansion is primarily the result of human activities, through increased nutrient inputs and various aspects of climate change. The Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) programme promoted international collaboration to understand HAB population dynamics in various oceanographic regimes and to improve the prediction of HABs. This volume introduces readers to the overarching framework of the GEOHAB programme, factors contributing to the global expansion of harmful algal blooms, the complexities of HABs in different habitats, and the forward-looking issues to be tackled by the next generation of GEOHAB, GlobalHAB. The programme brought together an international team of contributing scientists and ecosystem managers, and its outcomes will greatly benefit the international research community.

Globally, there are 3 400 to 4 000 described species of marine microalgae but only 1 to 2 percent are considered to be harmful. Harmful algal blooms (HABs) have significant impacts on food safety and security through contamination or mass mortalities of aquatic organisms. The impacts and mass mortalities of marine species caused by harmful algae are not new and have been recorded for decades. However, there is growing concern that these events will increase due to accelerating global warming, climate change and anthropogenic activities. Indeed, if not properly controlled, aquatic products contaminated with HAB biotoxins are responsible for potentially deadly foodborne diseases and when rapidly growing, HAB consequences include reduced dissolved oxygen in the ocean, dead zones, and mass mortalities of aquatic organisms. Improving HAB forecasting is an opportunity to develop early warning systems for HAB events such as food contamination, mass mortalities, or foodborne diseases. Surveillance systems have been developed to monitor HABs in many countries; however, the lead-time or the type of data (i.e. identification at the species-level, determination of toxicity) may not be sufficient to take effective action for food safety management measures or other reasons, such as transfer of aquaculture products to other areas. Having early warning systems could help mitigate the impact of HABs and reduce the occurrence of HAB events. The Joint FAO-IOC-IAEA technical guidance for the implementation of early warning systems (EWS) for HABs will guide competent authorities and relevant institutions involved in consumer protection or environmental monitoring to implement early warning systems for HABs present in their areas (marine and brackish waters), specifically those affecting food safety or food security (benthic HABs, fish-killing HABs, pelagic toxic HABs, and cyanobacteria HABs). The guidance provides a roadmap for stakeholders on how to improve or implement an EWS for HABs and biotoxins, where appropriate. It is important to note that not all countries and institutions can implement the same level of EWS for HABs, and this guidance is intended mainly for those who seek to broaden existing early warning systems, or who are just beginning to consider putting a system in place.

In the marine environment, single-celled, microscopic, plant-like organisms naturally occur in the well-lit surface layer of any body of water. These organisms, referred to as phytoplankton or microalgae, form the base of the food web upon which nearly all other marine organisms depend. Algal bloom is a rapid increase in or accumulation of the population of about 300 species of algae due to excess nutrients (eutrophication), and is of major global interest as it causes reduction in species diversity, abrupt changes in water quality, and discoloration of the water (green, yellow, brown or red) depending on the species of algae and the type of pigments they contain. Dying blooms can also be an environmental concern as when the cells sink and decay, bacteria break down the organic material, which in turn strips oxygen from the water. This microbial oxygen demand at times leads to very low oxygen levels in the bottom waters, harming aquatic life. Documentation of this sporadic high abundance of algae, together with the significant species richness of the diatoms, requires comprehensive studies in the Sundarban coastal environment, which is facing severe degradation due to natural & anthropogenic stressors. In addition, a better understanding of the effects of algal blooms on seafood quality, the complex biological, chemical and physical interactions and subsequent effects on trophodynamics is needed to develop strategies for effective coastal zone management. The book discusses the occurrence of harmful algal blooms (HABs) caused by the dinoflagellates of the genus Alexandrium and Karenia, or diatoms of the genus Pseudo-nitzschia, which have large and varied impacts on marine ecosystems (such as large-scale marine mortality events that have been associated with various types of shellfish poisonings) depending on the species involved, the environment where they are found, and the mechanism by which they exert negative effects. HABs represent a major environmental problem in all regions of the U.S., and their occurrence is on the rise due to increased nutrient pollution. HABs have severe impacts on human health, aquatic ecosystems, and the economy. Such blooms, known colloquially as red tides due to their red or brown hues, are increasing in frequency and magnitude worldwide as a result of changes in oceanic climate, increased coastal eutrophication and enhanced long-distance dispersal in ballast water. As such, the book offers an in-depth account of the complex biological, chemical and physical interactions of the algal blooms (both innocuous and harmful ones). It also discusses the highly topical issue of the impact of global climate change on the frequency and severity of HABs in the context of alterations in temperature, stratification, light and ocean acidification. Focusing on both basic and applied limnology, this book is a reliable and up-to-date reference resource for students, teachers and researchers engaged in the field of coastal research/management at regional and global scales.

Written by environmental health experts with long teaching and professional careers in policy and public health, the third edition of Environmental Policy and Public Health comprises two volumes addressing key physical hazards in the environment that impact public health. The first volume on Principal Health Hazards and Mitigation is complemented by the second volume, Emerging Health Hazards and Mitigation. The health of the environment is inextricably linked to that of people. Thoroughly updated, Volume 1 describes how the quality of air, water, and food is threatened by the presence of toxic substances and explains why climate change is a global health priority already impacting human health and the environment. The mitigations discussed in this volume are twofold: policies that are intended for control of specific hazards and suggested hazard interventions. The role of policy in addressing each of these key environmental health areas is extensively discussed in this volume as well. Each chapter explains step by step how new environmental health issues are translated into public health policies and concludes with practice questions to facilitate interactive learning for upper-level undergraduate and graduate students taking courses in public health and environmental sciences. The step-by step approach, as well as the case studies and practice questions, allow for a diverse portfolio of in-person and hybrid pedagogical strategies and tools at the fingertips of faculty who not only teach policy courses, but whose course topics, such as climate and health, have policy relevance.

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.

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.

This latest Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) will again form the standard reference for all those concerned with climate change and its consequences, including students, researchers and policy makers in environmental science, meteorology, climatology, biology, ecology, atmospheric chemistry and environmental policy.