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Mass kill of marine fauna was recorded from Kaštela Bay (eastern Adriatic coast) in September 1994. Mass kills of organisms in Kaštela Bay are relatively frequent and have occured repeatedly for the past fifteen years due to the autochtonous red tide bloom of Gonyaulax polyedra. The analysis of sea water samples collected nine days before the kill showed that regular red tide bloom of G. polyedra took place. However, during the kill period this organisms was not present in the samples. Only two heterotrophic species Polykrikos schwartzi and Noctiluca scintillans were found containing clearly visible cells of G. polyedra.

Spontaneous precipitation of calcium carbonates in the presence of foreign ions, selected organic substances and suspended mineral particles was investigated. In the model system total initial concentrations of calcium and carbonate species, as well as the ionic strength, were similar to those in the seawater. Vaterite was the only phase precipitated from model system. The addition of magnesium and strontium slightly retarded precipitation, while the addition of fulvic acid inhibited the process almost completely. In contrast, the addition of montmorillonite caused almost instantaneous precipitation of calcite, indicating montmorillonite as the suitable substrate for the overgrowth of this polymorph.