Abstract
Dissolved organic matter in the interstitial water of the bottom sediments (DOMI) collected from Yonago Bay in Lake Nakanoumi was separated to six organic fractions (F-1, F-2, F-3, F-4, F-5 and F-6) by gel chromatography. The effects of these fractions on the yield of phytoplanktons were examined by adding them to algal growth medium and comparing with that of control. The test phytoplanktons were isolated from brackish Lake Nakanoumi and then cultured in an aseptic condition.
The growth and the rate of Asterionella japonica, Coscinodiscus sp., Chaetoceros sp., Prorocentrum minimum and Planktonema lauterbornii were considerably accelerated by addition of DOMI (F-1, F-4, F-5 and F-6), whereas addition of DOMI (F-2 and F-3) did show inhibitory effect on the growth of some phytoplankton species.
