(2002). The Effects of Harmful Algal Blooms on Aquatic Organisms. Reviews in Fisheries Science: Vol. 10, No. 2, pp. 113-390.

The Effects of Harmful Algal Blooms on Aquatic Organisms

Food and Agriculture Organization (FAO) The Food and Agriculture Organization (FAO), established in 1945, is a UN specialized agency that provides global data and expertise on agri­ culture and nutrition, fisheries, forestry, and other food and agriculture– related issues. FAO is the UN system’s largest autonomous agency, with headquarters in Rome, 78 country offices and 15 regional, sub–regional, and liaison offices, including one located in Washington, D.C. FAO’s highest policy–making body, the biennial General Conference, comprises all 183 FAO member countries plus the European Commission. The General Conference determines FAO policy and approves FAO’s reg­ ular program of work and budget. The 31st Conference, meeting in November 1999, re–elected Director–General Jacques Diouf (Senegal) to a second six–year term through December 2005. Each biennial Confer­ ence elects a 49–member Council that meets semi–annually to make rec­ ommendations to the General Conference on budget and policy issues. The North America region, which comprises the United States and Can­ ada, is allocated two seats on the Council and one seat each on FAO’s Program, Finance, and Constitutional and Legal Matters (CCLM) Com­ mittees. The United States holds the North American seats on the Finance and Joint Staff Pension Committees through December 2003. Canada holds the North American seat on the CCLM and Program Committees through December 2003. The United States participated at the World Food Summit: Five Years Later meeting held at FAO headquarters June 10–13, 2002, to discuss progress towards attaining the 1996 World Food Summit target of reduc­ ing the world’s number of hungry and malnourished by half by 2015. The United States presented new initiatives to improve agriculture productivity as a significant contribution toward meeting that goal. U.S. Secretary of Agriculture Ann Veneman, leading the U.S. delegation, joined other min­ isters and heads of state and government in adopting a Declaration, “The International Alliance Against Hunger,” which reiterated the goals of the 1996 World Food Summit and stated, inter alia, “we are committed to

https://www.jstage.jst.go.jp/article/jve1997/7/2/7_2_107/_pdf

Food and Agriculture Organization (FAO) ホームページの活用法

Saxitoxin (STX) and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs). PSTs are the causative agents of paralytic shellfish poisoning (PSP) and are mostly associated with marine dinoflagellates (eukaryotes) and freshwater cyanobacteria (prokaryotes), which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified in several cyanobacterial genera including Anabaena, Cylindrospermopsis, Aphanizomenon Planktothrix and Lyngbya. STX and its analogs can be structurally classified into several classes such as non-sulfated, mono-sulfated, di-sulfated, decarbamoylated and the recently discovered hydrophobic analogs—each with varying levels of toxicity. Biotransformation of the PSTs into other PST analogs has been identified within marine invertebrates, humans and bacteria. An improved understanding of PST transformation into less toxic analogs and degradation, both chemically or enzymatically, will be important for the development of methods for the detoxification of contaminated water supplies and of shellfish destined for consumption. Some PSTs also have demonstrated pharmaceutical potential as a long-term anesthetic in the treatment of anal fissures and for chronic tension-type headache. The recent elucidation of the saxitoxin biosynthetic gene cluster in cyanobacteria and the identification of new PST analogs will present opportunities to further explore the pharmaceutical potential of these intriguing alkaloids.

https://www.mdpi.com/1660-3397/8/7/2185/pdf

Neurotoxic Alkaloids: Saxitoxin and Its Analogs

Metabolites from symbiotic bacteria

The cyanobacteria or "blue-green algae", as they are commonly termed, comprise a diverse group of oxygenic photosynthetic bacteria that inhabit a wide range of aquatic and terrestrial environments, and display incredible morphological diversity. Many aquatic, bloom-forming species of cyanobacteria are capable of producing biologically active secondary metabolites, which are highly toxic to humans and other animals. From a toxicological viewpoint, the cyanotoxins span four major classes: the neurotoxins, hepatotoxins, cytotoxins, and dermatoxins (irritant toxins). However, structurally they are quite diverse. Over the past decade, the biosynthesis pathways of the four major cyanotoxins: microcystin, nodularin, saxitoxin and cylindrospermopsin, have been genetically and biochemically elucidated. This review provides an overview of these biosynthesis pathways and additionally summarizes the chemistry and toxicology of these remarkable secondary metabolites.

https://www.mdpi.com/1660-3397/8/5/1650/pdf

On the chemistry, toxicology and genetics of the cyanobacterial toxins, microcystin, nodularin, saxitoxin and cylindrospermopsin.

Many pufferfish of the family Tetraodontidae possess a potent neurotoxin, tetrodotoxin (TTX). In marine pufferfish species, toxicity is generally high in the liver and ovary, whereas in brackish water and freshwater species, toxicity is higher in the skin. In 1964, the toxin of the California newt was identified as TTX as well, and since then TTX has been detected in a variety of other organisms. TTX is produced primarily by marine bacteria, and pufferfish accumulate TTX via the food chain that begins with these bacteria. Consequently, pufferfish become non-toxic when they are fed TTX-free diets in an environment in which the invasion of TTX-bearing organisms is completely shut off. Although some researchers claim that the TTX of amphibians is endogenous, we believe that it also has an exogenous origin, i.e., from organisms consumed as food. TTX-bearing animals are equipped with a high tolerance to TTX, and thus retain or accumulate TTX possibly as a biologic defense substance. There have been many cases of human intoxication due to the ingestion of TTX-bearing pufferfish, mainly in Japan, China, and Taiwan, and several victims have died. Several cases of TTX intoxication due to the ingestion of small gastropods, including some lethal cases, were recently reported in China and Taiwan, revealing a serious public health issue.

/pdf/tetrodotoxin-distribution-and-accumulation-in-aquatic-25qy95b6z1.pdf

Osamu Arakawa

Papers

Tetrodotoxin – Distribution and Accumulation in Aquatic Organisms, and Cases of Human Intoxication

Ostreopsis sp., a possible origin of palytoxin (PTX) in parrotfish Scarus ovifrons.

TTX accumulation in pufferfish.

Toxicity of pufferfish Takifugu rubripes cultured in netcages at sea or aquaria on land

Occurrence of saxitoxins as a major toxin in the ovary of a marine puffer Arothron firmamentum.