Results are presented about the changes in chlorophyll a density, carbon fixation and nutrient levels in the surface waters of three transects of the southern South China Sea (SCS), northern Java Sea (JS) and eastern Indian Ocean (IO) during April 5~16 of 2011. The in situ Chl a concentration and carbon fixation showed decreasing trends from high to low latitude along the three transects, while the photosynthetic rate of phytoplankton estimated from 14 C incorporation displayed no simple variation with latitude. Chl a concentration and carbon fixation in the IO water was lower than that in the JS water. Higher salinity and lower contents of dissolved inorganic nitrogen (DIN) and silicate (SiO3 2− ) characterized the IO water as compared to the SCS or JS water, and the PO4 3− content was lower in the IO water than in the SCS or JS water in most cases. Our results also indicate the importance of DIN and SiO3 2− concentrations for the geographical changes in phytoplankton biomass and primary productivity among the three regions.

The microbial degradative characteristics of three phthalate ester isomers (ortho-, meta-, and para- benzene dicarboxylic esters, DMP,DMI, and DMT respectively for short) by a degrading bacterium isolated from mangrove soil were investigated. The bacterium was identified as Rhodococcus ruber with 16S rDNA sequencing. Experimental results showed that as the sole source of carbon and energy, DMP could be degraded and the degradation intermediates were identified as mono-methyl phthalate(MMP) and phthalic acid (PA). The tentative pathway proposed for degradation of DMP by the bacterium under aerobic condition was through monoester initially, and further degradation of monoester produced phthalic acid, and finally CO_ 2 and H_ 2O. DMI and DMT at a concentration of 50mg·L -1 were degraded within 10 days by Rhodococcus ruber, but the intermediates accumulated in the culture medium. the results suggest that the degradation of phthalate ester isomers was related to the structures of chemicals.