Transfer of paralytic shellfish toxins via marine food chains: a simulated experiment / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the transfer of paralytic shellfish toxins (PST) using four simulated marine food chains: dinoflagellate Alexandrium tamarense --> Artemia Artemia salina --> Mysid shrimp Neomysis awatschensis; A. tamarense --> N. awatschensis; A. tamarense --> A. salina --> Perch Lateolabrax japonicus; and A. tamarense --> L. japonicus.</p><p><b>METHODS</b>The ingestion of A. tamarense, a producer of PST, by L. japonicus, N. awatschensis, and A. salina was first confirmed by microscopic observation of A. tamarense cells in the intestine samples of the three different organisms, and by the analysis of Chl.a levels in the samples. Toxin accumulation in L. japonicus and N. awatschensis directly from the feeding on A. tamarense or indirectly through the vector of A. salina was then studied. The toxicity of samples was measured using the AOAC mouse bioassay method, and the toxin content and profile of A. tamarense were analyzed by the HPLC method.</p><p><b>RESULTS</b>Both A. salina and N. awatschensis could ingest A. tamarense cells. However, the ingestion capability of A. salina exceeded that of N. awatschensis. After the exposure to the culture of A. tamarense (2000 cells x mL(-1)) for 70 minutes, the content of Chl.a in A. salina and N. awatschensis reached 0.87 and 0.024 microg x mg(-1), respectively. Besides, A. tamarense cells existed in the intestines of L. japonicus, N. awatschensis and A. salina by microscopic observation. Therefore, the three organisms could ingest A. tamarense cells directly. A. salina could accumulate high content of PST, and the toxicity of A. salina in samples collected on days 1, 4, and 5 of the experiment was 2.18, 2.6, and 2.1 MU x g(-1), respectively. All extracts from the samples could lead to death of tested mice within 7 minutes, and the toxin content in artemia sample collected on the 1st day was estimated to be 1.65 x 10(-5) microg STX equal/individual. Toxin accumulation in L. japonicus and N. awatschensis directly from the feeding on A. tamarense or indirectly from the vector of A. salina was also studied. The mice injected with extracts from L. japonicus and N. awatschensis samples that accumulated PST either directly or indirectly showed PST intoxication symptoms, indicating that low levels of PST existed in these samples.</p><p><b>CONCLUSION</b>Paralytic shellfish toxins can be transferred to L. japonicus, N. awatschensis, and A. salina from A. tamarense directly or indirectly via the food chains.</p>

Environmental and health effects associated with Harmful Algal Bloom and marine algal toxins in China / 生物医学与环境科学（英文）

The frequency and scale of Harmful Algal Bloom (HAB) and marine algal toxin incidents have been increasing and spreading in the past two decades, causing damages to the marine environment and threatening human life through contaminated seafood. To better understand the effect of HAB and marine algal toxins on marine environment and human health in China, this paper overviews HAB occurrence and marine algal toxin incidents, as well as their environmental and health effects in this country. HAB has been increasing rapidly along the Chinese coast since the 1970s, and at least 512 documented HAB events have occurred from 1952 to 2002 in the Chinese mainland. It has been found that PSP and DSP toxins are distributed widely along both the northern and southern Chinese coasts. The HAB and marine algal toxin events during the 1990s in China were summarized, showing that the HAB and algal toxins resulted in great damages to local fisheries, marine culture, quality of marine environment, and human health. Therefore, to protect the coastal environment and human health, attention to HAB and marine algal toxins is urgently needed from the environmental and epidemiological view.