Abstract: The study on the effects of pollutants discharge on red tide occurrence in eastern sea area of Shenzhen showed that the occurrence frequency of dinoflagellate red tide had significant positive correlations with the net discharge of total nitrogen (TN) and total phosphorous (TP) as well as the N/P ratio of the discharge. The thresholds of net discharged TN and TP were estimated to be 3.917×10³ t and 2.123×10⁴ t, respectively. No significant correlation was observed between diatom red tide and alongshore pollutants discharge. An example was given to illustrate the means of pollutants discharge control.

Key words: assimilates accumulation and distribution., ¹³C, organic carbon, photosynthetic characteristics, organic fertilizer