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

1993年对菲律宾和印度尼西亚的有毒浮游生物或中毒贝类进行了初步调查。由于发生了大面积的有毒赤潮，造成许多受害者，因此在菲律宾的10个地区进行了深入研究。浮游生物样本中未发现有毒鞭毛藻，但部分海域沉积物中有许多囊状物。在棉兰老岛卡米金岛采集的贝类标本中检出麻痹和腹泻毒素。这是热带地区首次发现腹泻毒素。在班乃岛萨皮安湾进行的后续研究证实，致病生物为尾尾恐龙（Dinophysis caudata）和d.m miles。1994年主要调查是在马尼拉湾进行的。水质高度富营养化。总氮最高为87 muM（平均29.4 muM），总磷最高为10.3 muM（平均4.15 muM）。由于水中含有的颗粒物质比可溶性氮和磷多，浮游植物对这些元素的吸收速率和周转率被认为很高。沉降速率为0.91 cm/yr。在中心区域和1.5厘米/年。在东海岸。有毒鞭毛藻巴hamense （Pyrodinium bahamense）主要分布在最内层和巴丹海岸6 m以下的浅水区。该物种的静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，该物种被认为在几十年内曾在该地区多次出现，但最近在红潮和贝类中毒事件后才被确认。在印度尼西亚，在雅加达湾和弗洛雷斯群岛进行了密集调查，但没有发现麻痹毒素产生者。底栖有毒物种，利马原心在弗洛雷斯群岛被发现。在马来西亚，发现了巴哈门火龙花。在中国，亚历山大菌属被确认为南部沿海水域的有毒物种。

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.