Effects of Industrial Effluents Containing Inorganic Materisals such as Chromate Treatment Water on the Growth of Several Species of Marine Phytoplankton

Abstract

Dokai Bay (Kitayushu City, Japan) receives the effluents from two different chromate processes of steel, an expensive-nonferrous-metal recovery process of iron sulfide, and an inorganic manure-producing process: these are the main sources of inorganic pollutants.
Among five phytoplankton tested, the growths of the two species, Skeletonema costatum and Olisthodiscus sp., which cause the red tides in Dokai Bay were stimulated at the early logarithmic phase as well as the stationary phase by the addition of four kinds of effluents, compared with those of their controls. These two species were more tolerant of the inhibitory effects of the effluents than were the other three species and strains: Chaetoceros curvisetus which was isolated from Dokai Bay and S. costatum and Olisthodiscus sp. which were isolated elsewhere. These patterns of the growth response of the five species and strains of plankton to the effluents which mainly contained inorganics were similar to those patterns of the growth response to the the effluents which mainly contained orgaincs reported in previous paper.
These results suggest that the growth specificities of the two kinds of plankton which caused the red tides in Dokai Bay to a variety of industrial effluents discharged into the bay could be sufficient to account for outbreaks of the red tide here.