抄録
Lake Takahoko in Aomori Prefecture is known to be a brackish-water lake leading to the Pacific Ocean by a narrow waterway. Diatom thanatocenoses from surficial sediments and water properties such as temperature, DO, salinity, conductivity, turbidity and pH were investigated.
The results are as follows:
(1) Most of the lake water is mesohaline, although oligohaline water exists partially in the innermost part of the lake.
(2) Bottom sediments, from deeper than 2m water depth, are composed of black surficial oozes smelling strongly of H2S.
(3) A total 137 taxa, belonging to 40 genera and comprising 128 species and 9 varieties, were found in the surficial sediments. Diatom assemblages are composed of fresh and fresh-brackish water species (46.3-83.5%), brackish water species (6.5-25.0%), and marine and marine-brackish water species (10.0-36.0%).
