Department of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, 386-8567, Ueda, Nagano, Japan,
Environ Health Prev Med. 2007 Jan;12(1):33-9. doi: 10.1007/BF02898190.
The aim of this study is to clarify the long-term dynamics of the red tide occurring in Lake Kawaguchi.
The measurement of environmental factors and water sampling were carried out monthly at a fixed station in Lake Kawaguchi's center basin from April 1993 to March 2004. On June 26, 1995, the horizontal distribution ofPeridinium bipes was investigated using a plastic pipe, obtaining 0∼1-m layers of water column samples at 68 locations across the entire lake.
P. bipes showed an explosive growth and formed a freshwater red tide in the early summer of 1995, when the nutrient level was higher than those in the other years, particularly the phosphate concentration in the surface layer. The dissolved total phosphorus (DTP) concentration was sufficient forP. bipes growth in that year. In the study of its horizontal distribution,P. bipes was found at all the locations. The numbers of cells per milliliter ranged from 67 to 5360, averaging 1094±987 cells/ml, with particularly high densities along the northern shore. Since then,P. bipes has annually averaged about 25 cells/ml in Lake Kawaguchi.
We observed that the red tide caused byP. bipes correlates with a high DTP concentration in Lake Kawaguchi.
本研究旨在阐明发生在河口湖的赤潮的长期动态变化。
1993 年 4 月至 2004 年 3 月期间，每月在河口湖中心盆地的一个固定站进行环境因素测量和水样采集。1995 年 6 月 26 日，使用塑料管对双鞭甲藻在整个湖面上的水平分布进行了调查，在 68 个位置获得了 0∼1 米深的水柱样本。
双鞭甲藻在 1995 年初夏大量繁殖，形成淡水赤潮，此时营养水平高于其他年份，特别是表层磷酸盐浓度。当年，溶解总磷（DTP）浓度足以支持双鞭甲藻的生长。在其水平分布研究中，在所有位置都发现了双鞭甲藻。每毫升细胞数范围为 67 至 5360，平均值为 1094±987 个/ml，北部沿岸的密度特别高。此后，河口湖中的双鞭甲藻每年平均约为 25 个/ml。
我们观察到，双鞭甲藻引发的赤潮与河口湖中高 DTP 浓度有关。
