Study On Meiofauna And Deep-sea Sediment 18S RDNA Gene Diversity In China Contract Area

Meiofauna are species-richness and widely distributed in the ocean. They play an important role in the marine debris food chain. They are not only the food of fish, shrimp and crab, but also important in the benthic energy flow and materials cycle. Besides, meiofauna are good environmental indicator organism because they move slowly and are sensitive to the change of environment. Meiofauna variation is one of the important deep-sea environmental assessable parameters in the deep-sea mineral resources prospecting activity of the polymetallic nodule area in the northeast Pacific. At present, the Kaplan plan leading by International Seabed Authority has allied multi-country scientists to study the deep-sea polymetallic nodule areas that include the projects of meiofauna variation and gene flow. China is one of the seven pioneer investment countries and has gained the priority to prospect and exploit 75000 square kilometers China Contract Area. Therefore, it is our duty to study and protect the deep-sea environment.This study is part of the project of "Natural Variability of Baseline Study in China Contract Area". The composition, density, biomass and distribution of meiofauna in China Contract Area and Antarctic Zhongshan Station surrounding sea have been studied. By comparing the meiofauna in the Contract Area and Antarctic Zhongshan Station surrounding sea with that in the Arctic area, this paper have discussed the relationship between meiofauna and the environmental factors. At the same time, the deep-sea benthic sediments in China Contract Area have been studied by the method of DNA survey. The results show as following:1. A total of 48 deep-sea meiofauna samples from the eastern and western parts of China Contract Area were analyzed. 14 meiofaunal taxa were found, of which nematoda was the dominant group and accounted for 44.00-84.09% of the total meiofauna found in the samples, following was copepoda with 11.36-40.00%. The meiofauna abundance was between 3.5 ind./10cm~2 and 23.3 ind./10cm~2. The biomass varied from 1.227 μgC/10cm~2 to 5.698 μgC/10cm~2. There were 10 groups in the Antarctic research station A. Nematode was the most dominant species, accounting for 84.12% of the total meiofauna found in the samples. Followed with copepoda, with 12.5% of the total. The meiofauna density was 334.23ind/10cm~2, and the biomass was 585.7 μgC/10cm~2. The nematode density was 281.16 ind/10cm~2, while the copepoda was 41.50 μgC/10 cm~2. And the nematoda sizes were 551μm to 1472.4 μm.