How the pollution stress acting on the phytoplankton populations——an observation by the experimental enclosed ecosystem

A marine enclosed ecosystem experiment was conducted by Chinese and Canadian scientists in Xiamen in April 1985.PoVutants of heavy metals mixed with Cu, Hg, Pb, Zn and Cd and of suspended sediments were added to bags volumed about 10 m³.It was showed that during 21 days the effects on the plankton populations were evident in the bags due to the contamination, i.e.the growth of diatom population reduced to different levels characterized by the lag appearance of density peaks, low instant growth rate end delay of doulbling time with low biomass.A strong grazing from the pollutant affected zooplankton population resulted in heavy stress on the growth of algal population. As a result, the stress transferred to the phytoplankton population through the herbivores.