Effect of zinc sulphate on the growth of mono- and multispecies cultures of some marine plankton algae

摘要: The effect of zinc sulphate has been investigated in mono- and multispecies cultures the dinoflagellatesScrippsiella faeroense, Prorocentrum micans andGymnodinium splendens diatomsSchroederella schroederi andThalassiosira rotula. Multiplication rate, vivo chlorophyll fluorescence, maximum cell densities Zn-conditioned disturbance species equilibrium were used as criteria sublethal toxic inhibition. In monocultures, first became manifest after addition 0.01 to 0.1 mg Zn++ · l−1. Diatoms proved be more sensitive than dinoflagellates. cultures, growth each depended on ratio inocula. Interrelation between interspecific competition Zn-caused decrease number algal cells regulated further cultures. Algal sensitivity increased with combined test medium: a 5-species culture changes appeared already 0.005 few cases, depressed some an appreciable extent, even control At resulting low numbers, apparent only higher concentrations from 5 10 Morphological aberrations inScrippsiella faeroense diatoms 1 l−1 respectively. results show that experiments are method for investigating influence plankton algae monoculture experiments. natural communities, however, toxicity heavy metals may become effective at considerably lower limit concentrations; this is suggested by simplified model investigations laboratory.