Abstract: Based on the data from two oceanographic surveys in North Jiangsu shoal in November 2010 and May 2011, this paper analyzed the shrimp density, population composition, and dominant species in the shoal, and, in combining with the unique topography of the sand ridge and tidal creek system in the shoal, studied the effects of the topography and tidal current on the quantitative distribution of the shrimps. A total of 15 shrimp species were identified, among which, Leptochela gracilis and Acetes chinensis were the dominant species in spring and autumn, respectively, according to the index of relative significance (IRI). As compared with those in autumn, the biomass and individual density of the shrimps were relatively high in spring, being 35.64 vs. 9.24 kg·km^-2, and 35.42×10³  vs. 25.92×10³ ind·km^-2, respectively. According to the β value, there was a close correlation between the variations of the total shrimp density and the main dominant species density, and the two had the same horizontal distribution pattern. Due to the unique topography of the sand ridge and tidal creek system in the shoal, in addition to the forward wave of East China Sea and the rotating wave of Yellow Sea, the tidal current concentrated centripetally from north, east, and south, which was consistent with the direction of the tidal creeks. The flow rate of the tidal current was faster in tidal creeks than on sand ridges, which made the shrimp biomass and individual density be far greater in tidal creeks than on sand ridges, and slightly higher in the deep grooves between sand ridges and intertidal fords than on the sand ridges, no matter in spring or in autumn.

Key words: Tiantong evergreen broad-leaved forest, allometric growth model, negative exponential function, litterfall amount, dispersal.