Study on the Ecological Characteristics of Phytoplankton in a anti-season high efficient and ecological short neck clam (Ruditapes philiPpinarum) culture pond

Abstract:

The Ruditapes philippinarum high efficient eco-culture in the high area of dam inning zone of Putian city of Fujian province was studied for the period 2007 to 2008.The average size of Ruditapes philippinarum was 115 individuals per kilogram，the grain yield was 6247.5 kilograms per hectare.It can increase 28 % economic efficiency than traditional culture pattern. The results showed that the phytoplankton community was mainly composed of 34 species.The most dominant species were Skeletonema costatum，Prorocentrum sigmoides，Prorocentrum lima，Nitzschiella closterium，Prorocentrum micans. It dominated by Skeletonema costatum.The overwhelming dominance of this species lasted for more than five months.The cells abundance were between 0.02×104 cells/L and 190×104 cells/L in the different months. High cells abundance of phyplankton occurred in Nov. 2007 and Mar. 2008. Low cells abundance of phyplankton occurred in Jan. and Feb. 2008. The temperature，transparency，inorganic nitrogen，inorganic phosphorus，dissolved oxygen，chemical oxygen demand，species diversity values and evenness index of phytoplanktons were used to analyze the characteristics of community structure of phytoplanktons in the investigation area.Long term artificial fertilizing in eutrophic aquatic ecosystem had effected the phytoplankton species composition， it led to the elevation of the species diversity values and the decline of evenness of phyplankton. The dominant species were remarkable.Only few dominant species，such as Skeletonema costatum which was favourable diet for Ruditapes philippinarum increased rapidly.It was helpful to increase the yield of Ruditapes philiPpinarum.