Study on Areal Expansion of Harmful Plankton

有害浮游生物面积扩大研究

基本信息

批准号：
06454099
负责人：
FUKUYO Yasuwo
金额：
$ 4.22万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06454099/
关键词：
Harmful plankton Dinoflagellate Toxic dinoflagellate Alexandrium Cyst Paralytic shellfish poisoning Areal Expansion of Harmful Plankton Cyst Sedimentation

项目摘要

Surface sediments were collected by using TU-1 piston corer at Tanabe Bay, Wakayama Prefecture, and Ofunato Bay, Iwate Prefecture, to investigate whether toxic dinoflagellates of the areas occurred long time before the first finding, by comparing cyst distribution in the sediment with plankton record.The sediment core was cut every 1 or 2 cm interval.Alexandrium cyst concentration, age of sediment, and compaction rate of each fraction were analyzed.The TU-1 corer was evaluated as the best among three types of corers including KK and Frager gravity corers regarding the amount of sediment collected and avoidance of mixture of layrs.For measurement of sediment age, the vertical distribution of lead 210 was analyzed by using alpha emission from polonium 210, in addition to the measurement of water contents of the fraction.In Tanabe Bay, Alexandrium cysts were found in all fractions from surface to 30cm deep, having maximum concentration of 175 cysts/cm^3 at3-4cm deep.The deepest layr of 28-30cm in which Alexandrium cysts were detected accumulated around 1945, taking into account of the sedimentation rate as 0.98 cm/y and the compaction rate.As the first finding of planktonic Alexandrium was made in 1980, the organism has already occurred about 35 years before the first observation.In Ofunato Bay, Alexandrium cysts were found in all fractions from surface to 14cm deep, having maximum consentration of 1,620 cysts/cm^3at2-3cm deep.The deepest layr of 12-14cm in which Alexandrium cysts were detected deposited between 1898 and 1914, taking into account of the sedimentation rate as 0.23cm/y and the compaction rate.As the first finding of planktonic Alexandrium was reported in 1963, the organism has already occurred about 50 to 60 years before the first observation.These findings indicate that Alexandrium has occurred a long time before the first observation, and invasion of the species might not occur recently.

Surface sediments were collected by using TU-1 piston corer at Tanabe Bay, Wakayama Prefecture, and Ofunato Bay, Iwate Prefecture, to investigate whether toxic dinoflagellates of the areas occurred long time before the first finding, by comparing cyst distribution in the sediment with plankton record.The sediment core was cut every 1 or 2 cm interval.Alexandrium cyst concentration, age of sediment, and compaction rate of分析了每一小部分。将Tu-1振动器评估为在包括KK和碎片重力搅拌在内的三种类型的旋塞中最好的，涉及收集的沉积物量和避免混合物的混合物。用于测量沉积物时代的垂直分布210的垂直分布210的垂直分布，通过使用210的Alpha发射，此外，除了bare Alex的测量范围内，还可以使用polonium 210的Alpha发射。在从表面至30厘米深的所有馏分中都发现了囊肿，最大浓度为175囊肿/cm^3 AT3-4厘米深。最高的28-30厘米的最深layr在1945年左右被检测到alexandrium囊肿，这是在1945年左右累积的，这是沉积速率的第一个汇总，并在1980 cm and compaction速率上进行了调查。在第一次观察之前已经发生了大约35年。 0.23厘米/y和压实率。正如1963年报道了浮游生物的第一个发现，该生物体已经发生在首次观察之前的50至60年。这些发现表明，这些发现是在首次观察之前很长时间发生的，并且可能不会发生这种物种的入侵。