Accumulation of phytoplankton in lake sediments estimated from photosynthetic pigments.

用高效液相色谱法对霞aura湖沉积物中浮游植物色素进行了分析。蓝绿藻特有的类胡萝卜素——紫棘烯酮和粘叶黄素的深度剖面在30年前为防止海水流入而修建的水闸（hitachigasuimon）之后有所增加。β -胡萝卜素的深度剖面表明，30年前湖泊藻类生物量下降，与水闸建设时期一致，之后随着蓝绿藻等淡水浮游植物的增加而增加。分析了贝加尔湖南部盆地沉积物中类胡萝卜素、叶绿素及相关色素的深度剖面。光合色素被发现在沉积物岩心中保存了几百年。沉积物中含有丰富的绿藻、硅藻、隐藻和蓝藻色素，叶绿素a和b的大部分以叶绿素素的形式保存下来。在整个岩心层中均检测到生物源苝，其存在表明沉积物处于缺氧状态。夏季在贝加尔湖发现了花青菌、溶藻菌。研究了贝加尔湖淡水中picocyanobacteria， Synechococcus spp.和Synechocystis spp.的色素组成，并估计了1994年8月贝加尔湖picocyanobacteria的分布和贡献。

Phytoplankton pigments in sediment of Lake Kasumigaura were analyzed by HPLC.The depth profiles of echinenone and myxoxanthophyll, which are characteristic carotenoids of blue-green algae, showed an increase after the lock gate (Hitachigawa-suimon) was constructed 30 years ago to prevent seawater coming into the lake. The depth profile of beta-carotene suggests that the algal biomass in the lake decreased 30 years ago, being consistent with the period of the construction of the lock gate, and then increased with the increase of freshwater phytoplankton such as blue-green algae.Depth profiles of carotenoids, chlorophylls and the related pigments in the sediments of southern basin of Lake Baikal were analyzed. The photosynthetic pigments were found to be preserved through the sediment cores which spanned several hundred years. Pigments originated from green-algae, diatoms, Cryptophyceae and cyanobacteria were abundant in the sediments and major part of chlorophyll a and b were preserved as pheophytin. Biogenic perylene was detected throughout the core layrs and its presence indicates that the sediment has been under an anoxic condition.Picocyanobacteria, Synechocystis limnetica have been observed in Lake Baikal during the summer. Pigment compositions of picocyanobacteria, Synechococcus spp. and Synechocystis spp. in freshwater was studied, and the distribution and contribution of picocyanobacteria in Lake Baikal on Augest 1994 was estimated.