Marine Biotoxins

This paper provides an extensive review of different aspects of five shellfish-poisoning syndromes (paralytic, diarrhoeic, amnesic, neurologic and azapiracid), as well as one fish-poisoning syndrome (ciguatera fish poisoning), and discusses in detail the causative toxins produced by marine organisms, chemical structures and analytical methods of the toxins, habitat and occurrence of the toxin-producing organisms, case studies and existing regulations. Based on this analysis, risk assessments are carried out for each of the toxins, and recommendations are elaborated to improve the management of these risks in order to reduce the harmful effect of these toxins on public health.

The emergence of marine and freshwater toxins in geographical areas where they have never been reported before is a concern due to the considerable impact on (sea)food contamination, and consequently, on public health. Several groups of marine biotoxins, in particular tetrodotoxins, ciguatoxins, and palytoxins, are included among the relevant marine biotoxins that have recently emerged in several coastal areas. A similar situation has been observed in freshwater, where cyanobacterial toxins, such as microcystins, could end up in unexpected areas such as the estuaries where shellfish are cultivated. Climate change and the increased availability of nutrients have been considered as the key factors in the expansion of all of these toxins into new areas; however, this could also be due to more intense biological invasions, more sensitive analytical methods, or perhaps even an increased scientific interest in these natural contaminations. The incidences of human intoxications due to the consumption of seafood contaminated with these toxins have made their study an important task to accomplish in order to protect human health. This Special Issue has a focus on a wide variety of emerging biotoxin classes and techniques to identify and quantify them.

This paper provides an extensive review of different aspects of five shellfish-poisoning syndromes (paralytic, diarrhoeic, amnesic, neurologic and azapiracid), as well as one fish-poisoning syndrome (ciguatera fish poisoning). It discusses in detail the causative toxins produced by marine organisms, chemical structures and analytical methods, habitat and occurrence of the toxin-producing organisms, case studies and existing regulations. Based on this analysis, risk assessments are carried out for each of the toxins, and recommendations are elaborated to improve the management of these risks in order to reduce the harmful effects of these toxins on public health. Contents Chapter 1: Introduction; Chapter 2: Paralytic Shellfish Poisoning (PSP); Chemical structures and properties, Methods of analysis, Source organism(s) and habitat, Occurrence and accumulation in seafood, Toxicity of PSP toxins, Prevention of PSP intoxication, Cases and outbreaks of PSP, Regulations and monitoring; Chapter 3: Diarrhoeic Shellfish Poisoning (DSP); Chemical structures and properties, Methods of analysis, Source organism(s) and habitat, Occurrence and accumulation in seafood, Toxicity of DSP toxins, Prevention of DSP intoxication, Cases and outbreaks of DSP, Regulations and monitoring; Chapter 4: Amnesic Shellfish Poisoning (ASP); Chemical structures and properties, Methods of analysis, Source organism(s) and habitat, Occurrence and accumulation in seafood, Toxicity of ASP toxins, Prevention of ASP toxins, Prevention of ASP intoxication, Cases and outbreaks of ASP, Regulations and monitoring; Chapter 5: Neurologic Shellfish Poisoning (NSP); Chemical structures and properties, Methods of analysis, Source organism(s) and habitat, Occurrence and accumulation in seafood, Toxicity of NSP toxins, Prevention of NSP intoxication, Cases and outbreaks of NSP, Regulations and monitoring; Chapter 6: Azaspiracid Shellfish Poisoning (AZP); Chemical structures and properties, Methods of analysis, Source organism(s) and habitat, Occurrence and accumulation in seafood, Toxicity of AZP toxins, Prevention of AZP intoxication, Cases and outbreaks of AZP, Regulations and monitoring; Chapter 7: Ciguatera Fish Poisoning (CFP); Chemical structures and properties of ciguatoxins, Methods of analysis, Source organism(s), habitat and distribution, Occurrence and accumulation in seafood, Toxicity of CFP toxins, Prevention of CFP intoxication, Cases and outbreaks of CFP, Regulations and monitoring; Chapter 8: Risk Assessment; Risk assessment for paralytic shellfish poisoning (PS), Risk assessment for diarrhoeic shellfish poisoning (DSP), Risk assessment for Amnesic shellfish poisoning (ASP), Risk assessment for neurologic shellfish poisoning (NSP), Risk assessment for azaspiracid shellfish poisoning (AZP), Risk assessment for ciguatera fish poisoning (CFP); Chapter 9: Conclusions and Recommendations; Conclusions, Recommendations.

Marine biotoxins may pose a threat to the human consumption of seafood and seafood products. The increasing global trade and higher demand for seafood products worldwide represents a challenge for food safety authorities, policy makers, food business operators, and the scientific community, in particular, researchers devoted to environmental sciences, toxicology, and analytical chemistry. In addition, due to changes in climate conditions and technological developments, new and emerging marine toxins are being detected in regions where they were previously unknown. This Special Issue highlight studies aiming to the develop detection methods for marine biotoxins for better understanding the dynamics of accumulation/elimination of marine biotoxins and their effects on marine organisms, as well as toxin exposure studies that aim to evaluate the risks associated with the consumption of contaminated seafood.

Marine Pharmacognosy: Action of Marine Biotoxins at the Cellular Level focuses on the study and utilization of marine drugs. This book discusses the methods of isolation and characterization of bioactive agents, bioassays, microcalorimetry, voltage-clamp techniques, toxin-induced alterations, measurement of muscle contraction, and kinetics of toxin-induced hemolysis. Organized into nine chapters, this book starts with an overview of the use and usefulness of marine bioactive agents as research tools. This text then examines the pharmacological effects of maculotoxin, which are similar to those of tetrodoxin and saritoxin. Other chapters consider the role of choline in general cellular processes. This book discusses as well the rate of hemolysis as a function of prymnesin concentration. The final chapter deals with the features of the prymnesin–membrane interaction. This book is a valuable resource for pharmacologists, bacteriologists, zoologists, physiologists, botanists, and oceanographers. Scientists involved in biological oceanography and comparative physiology will also find this book useful.

In areas where toxic algal blooms occur, the main affected organisms are shellfish, which, because of their high levels of filtration (clearance rate), accumulate high concentrations of nutrients and toxic phytoplankton in their visceral tissue. This accumulation of toxins in shellfish leads to a distribution of these toxins to their different non-visceral tissues. Chapter One of Marine Toxins: Detection Methods, Chemical and Biological Aspects and Health Effects discusses the detection and quantification of lipophilic marine biotoxins by liquid chromatography tandem mass spectrometry from endemic species and gastropods. Chapter Two present studies which use the similarity analysis of paralytic shellfish poisoning toxins (PSP-toxins) profile patterns to analyse epidemiological linkage of a group of toxins contaminated bivalves collected between years 2004 and 2015. Chapter Three provide an overview of the current status of biomarker use in the assessment of the effects of marine toxins on bivalve mollusks. Chapter Four reviews the latest research on the biological and clinical effects of caulerpenyne.

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.