Studies On Ecology Of Meiofauna In The Taiwan Strait And Its Adjacent Waters

Meiofauna are species-richness and widely distributed in the ocean.They play an important part 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.Miofauna research is an important component of marine biological survey.In-depth research of meiofauna is significance to understanding the marine benthic ecosystem structure and function, establishment of ecological dynamics model of water-benthic coupling mechanism, comprehensive study of marine fisheries resources and so on.Meiofauna also is environmental monitoring biological.It is significance to evaluation the state of the Taiwan Strait environment.Quantitative studies of the meiofauna in the Taiwan Strait and its adjacent waters were carried out in Jul.and Dec.2006.In this paper,we discussed abundance, biomass,community structure and biodiversity of the meiofauna and benthic copepods.The main results are as follows:A total of 14 groups of meiofauna were identified in the Taiwan Strait and its adjacent waters,such as Nematoda,Copepoda,Polychaeta,Ostracoda,Bivalvia, Gastropoda,Kinorhyncha,Nauplius,Amphipoda,Tanaidacea,Pycnogonida,Cumacea, Decapoda and Others.Freeing living Nematodes are the most dominant group, accounting for 84.87%(82.20%in summer cruise,89.13%in winter cruise) of the abundance of meiofauna.The benthic copepoda's abundance is in the second, accounting for 8.02%(11.01%in summer cruise,5.59%in winter cruise).The average abundance,biomass and production of meiofauna are 377.43±2.22ind/10cm~2,412.82±9.38μg·dwt/10cm~2 and 3715.38±84.42μg·dwt /10cm~2·a in summer cruise.In winter cruise the average abundance,biornass and production of meiofauna are 268.71±32.36 ind/10cm~2,310.59±0.65μg·dwt/10cm~2 and 2795.31±5.86μg·dwt/10cm~2·a. In terms of the meiofauna's horizontal distribution,stations near the middle of the Strait have higher abundance and biomass in summer cruise.In winter cruise the meiofauna abundance and biomass are higher in the southern and middle areas of the Strait than the northern area.In terms of vertical distribution,56.28%of total meiofauna is found in the surface sediment of 0-2cm in summer cruise.In winter cruise the meiofauna in 0-2cm accounting for 63.37%of the total abundance of meiofauna.There are 86.70%of meiofauna in 0-5cm sediment in summer cruise. 88.29%of meiofauna are found in 0-5cm in winter cruise.Correlation analyses between abundance and biomass of meiofauna and environmental factors show that Chl-a is the key factor that affects the distribution of meiofauna.The content of gravel, grit,powder and clay in sediment is the main factors which affect the abundance and biomass distribution of copepoda.Compared with other studies,the results in this study is lower.In terms of the ratio of nematoda and copepoda,there is no pollution in the Taiwan Strait and its adjacent waters.In this study,total of 63 species or taxa of benthic copepoda are identified.These copepods belong to 43 genuses,17 families and 4 orders Harpacticoida,Calanoida, Cyclopoida and Poecilostomatoida.The dominant species are:Halectinosoma sp,Typhlamphiascus sp,Amphiascus sp,Heteropsyllus sp,Ectinosoma sp and Amphiascoides sp.Water depth is similar in all stations,so the water depth is not the significant factor to the copepoda.Correlation Analysis between the sediment environment and the copepoda diversity shows that the sediment composes is the significant factor to the copepoda diversity.