AN ECOSYSTEM MODEL ANALYSIS OF THE EFFECT OF MINE TAILINGS ON THE EUPHOTIC ZONE OF A PELAGIC ECOSYSTEM

A computer analysis was performed on experimental results obtained when mine tailings were added to seawater.The Mixed Upper-Layer Ecotrophie Simulation (MULES) model was tested by changing the extinction coefficient and the abundance of heterotrophic zooflagellates.Increasing the extinction coefficient resulted in a delay of phytoplankton growth, an increase in zooplankton standing stock and better growth of autotrophic flagellates compared with diatoms.Zooflagellates in the ecosystem influence the growth of zooplankton; secondary production by zooplankton was markedly depressed at low levels of zooflagellates.These results are believed to be of general significance for the diagnosis of suspended sediment effects on planktonic ecosystems.