Organic geochemical studies of sinking particulate material in China sea area II

Conclusions We have for the first time studied the compositions of ketone, aldehyde and alcohol lipid compounds in sinking particulate materials from Yongshu Reef lagoon and the continental shelf of the East China Sea collected by sediment trap sampling apparatus. The results indicate that sinking particulate materials contain abundant isoprenoid ketone, aldehyde and alcohol lipid compounds which take part in marine chemical cycling. The compositional features of these compounds show that sinking particulate organic matter mainly comes from autochthonous marine organisms and Yongshu Reef lagoon has more submerged macrophytes-derived component, while the continental shelf of the East China Sea contains more dinoflagellate-derived constituent. The contribution of higher land plant to sinking particulate organic matter may be very small. In contrast, it is greater in Yongshu Reef lagoon than that in the continental shelf of the East China Sea. Sinking particulate organic matter in the two regions undergoes strong biochemical transformation processes before reaching the depth of 5 m to the sea floor, and its intensity is greater in Yongshu Reef lagoon than in the continental shelf of the East China Sea. These results have certain reference value to the researches of marine chemistry, marine biology and marine sedimentology in China, and reveal the importance of organic geochemistry to the study of oceanology.