Modeling the Dynamics of the Decomposed Ulva Prolifera Biotoxicity with Luminous Bacteria Method

Abstract

The “green tide” occurred frequently, however, their biotoxicity information is relatively scarce. In this study, we used luminescent bacteria test based on Vibrio fischeri (NRRL b-11177) to detect the biotoxicity of Enteromorpha prolifera in decomposition process. We added different biomasses of Enteromorpha prolifera to the same volume of seawater to simulate decomposition process. The biotoxicity was detected regularly. The comparative analysis showed that luminescent bacteria had high sensitivity to the biotoxicity in Enteromorpha prolifera decomposition. And the change of biotoxicity was closely related to the biomass of Enteromorpha prolifera. The more Enteromorpha prolifera added, the sample showed greater biotoxicity, got the grade III earlier and continued longer. Group E (32g/L) reached grade III on the 9th day of the experiment, and the number of days of grade III accounted for 95%. The decomposition of high concentration Enteromorpha prolifera produced obvious biotoxicity, and subsided slowly. Therefore, the area where “green tide” occured should cleanup in time to prevent the damage of the local ecological environment.