Bloom and spread mechanisms of toxic red tides in SE-Asia

1993年在这里进行了初步调查，菲律宾和印度尼西亚报告了有毒浮游生物或中毒的贝类。由于发生了大范围的有毒赤潮，受害者众多，菲律宾10个地区进行了密集的研究。在浮游生物样本中没有发现有毒的甲藻，但在一些地区的沉积物中发现了许多包囊。在棉兰老岛卡米金岛采集的贝类标本中检测到麻痹和腹泻毒素。这是在热带地区首次发现腹泻毒素。通过在班乃岛萨皮亚湾进行的后续研究，确认了病原菌为尾藻和马尾藻。1994年在马尼拉湾进行了主要调查。水质高度富营养化。总氮最大值为87微米(平均29.4微米)，总磷为10.3微米(平均4.15微米)。由于水体中颗粒物的含量高于可溶性氮和磷，浮游植物对这些元素的吸收率和周转率可能较高。沉降率为0.91厘米/年。在中心区，1.5厘米/年。在东海岸。有毒的甲藻，Bahamense，分布在最内侧和巴丹海岸6米以下的浅水中。该物种的休息囊广泛存在于几十年前积累的表层和深层沉积物中。因此，据推测，该物种在过去几十年中曾多次在该地区复发，但最近在发生赤潮和贝类中毒事件后被发现。在印度尼西亚，雅加达湾和弗洛雷斯群岛进行了密集的调查，但没有发现麻痹毒素产生者。在弗洛雷斯群岛发现了底栖有毒物种利马原甲藻。在马来西亚发现了Bahamense吡咯菌。在中国亚历山大藻(Alexandrium spp.)在南部沿海水域被确认为有毒物种。

In 1993 preliminary surveys were carried out at here toxic plankton or intoxicated shellfish was reported in the Philippines and Indonesia. As extensive toxic red tides had occurred with many victims, intensive research were made at 10 areas of the Philippines. No toxic dinoflagellate was found in plankton samples , however, many cysts were in sediment in some of the areas. Paralytic and diarrhetic toxins were detected in shellfish specimens collected at Camiguin Island of Mindanao Island. This is the first finding of the diarrhetic toxins in tropical area. Causative organisms were confirmed as Dinophysis caudata and D. miles by following researches conducted at Sapian Bay, Panay Island.In 1994 the main survey was conducted in Manila Bay. Water quality was highly eutrophic. Total nitrogen was 87 muM at maximum (average 29.4 muM) and total phosphorus 10.3 muM (average 4.15 muM). As water contained more particulate matters than soluble nitrogen and phosphorus, up-take rate into phytoplankton and turn over rates of the elements were presumed to be high. Sedimentation rate was 0.91 cm/yr. at the central area and 1.5 cm/yr. at the east coast. The toxic dinoflagellate, Pyrodinium bahamense, was distributed in shallower waters than 6 m of innermost and Bataan coast areas. The resting cyst of the species was widely found in surface and deeper sediments accumulated several decades ago. Therefore the species was presumed to have been recurring in the area several times in the decades, but recently recognized after incidents of red tide and intoxication of shellfish.In Indonesia intensive surveys were conducted at Jakarta Bay and Flores Islands, but no paralytic toxin producer could be found. Benthic toxic species, Prorocentrum lima was found in Flores islands. In Malaysia Pyrodinium bahamense was found. In China Alexandrium spp. were confirmed as toxic species in southern coastal waters.