CONTAMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND BACTERIAL DIVERSITY IN SURFACE SEDIMENTS OF FUGONG MANGROVE, CHINA

Abstract

Mangrove forest found in shorelines of tropical and subtropical zones thought to be support near shore marine production due to its high productivity. However, rapid industrialization and consequent contamination by persistent organic pollutants disturb the mangrove ecosystems. PAHs are one of the hazardous contaminants because of its ubiquity and genotoxicity. In the present study, effect of polycyclic aromatic hydrocarbons (PAHs) on the microbial community structure of surface sediments of Fugong mangrove, China was investigated. The concentrations of EPA 16 priority PAHs was measured by GC/MS and microbial community structure based on 5＇-terminal restriction fragment length polymorphism (T-RFLP) was analyzed using ABI 3100 automatic DNA sequencer. Concentrations of total PAHs ranged from 280.0 to 1206.8 ng/g dry weight and were lower than ER-L value suggested by Long et al. (1995). However, concentration of individual PAH compound such as dibenz(a,h)anthracene was higher than the ER-M value at several sampling sites and proportion of high molecular weight PAHs was higher than 90% of total PAHs implied the potent biological effect on mangrove organisms. The Shannon-Weaver diversity index of the dominant bacteria in surface sediment was similar between stations (3.58-4.23). Cluster analysis of microbial community structure revealed that the environmental conditions such as salinity, plantation etc. were more important for the distribution of microorganisms than concentrations of PAHs at the study area. [Supported by MEGRC & KOSEF-NSFC cooperative program (PN61300)].