夏季の広島湾における細菌と従属栄養性微小鞭毛虫類の出現密度の変動

Numerical Fluctuation of Bacteria and Heterotrophic Microflagellates in Hiroshima Bay of the Inland Sea of Japan in Summer 1990

Iwamoto Noriko

Imai Ichiro

Uye Shin-ichi

日本プランクトン学会報

Numerical fluctuations of bacteria, heterotrophic microflagellates (HMF) and autotrophic nanoplankton (ANP) were investigated at a station in Hiroshima Bay at two days intervals during the period from 18 July to 17 August, 1990. The average density of bacteria and HMF within the water column was highest at the beginning of the investigation, decreased to the end of July, and then was relatively constant. The cyclic oscillation pattern of the population abundance of bacteria and HMF was not found in the present study. The ranges of density observed were 1.16-4.30 x 10^6 cells•ml^<-1> for bacteria (mean: 2.40 x 10^6 cells • ml^<-1>), and 3.27-9.09 x 10^3 cells • ml^<-1> for HMF (mean: 5.07 x 10^3 cells • ml^<-1>). The average numerical and biomass ratios of bacteria to HMF were 481 and 1.08, respectively, which were smaller than the ratios previously reported. This means that HMF occurred more abundantly relative to bacteria in the present study area comparing to other areas. The density of ANP was more fluctuated than that of HMF, ranging from 2.41 x 10^3 to 59.00 x 10^3 cells • ml^<-1> (mean: 12.9 x 103 cells • ml^<-1>).

bacteria

細菌

heterotrophic microflagellates

従属栄養性微小鞭毛虫類

autotrophic nanoplankton

独立栄養性ナノプランクトン

Hiroshima Bay

広島湾

Zoology [ 480 ]

jpn

日本プランクトン学会

Copyright (c) 1993 The Plankton Society of Japan

[ISSN] 0387-8961

[NCID] AN00197015