Characteristics of the Fish Assemblage in the Intertidal Salt Marsh and Mudflat of the Yangtze Estuary

Abstract

During July 2015 to June 2016, two permanent sampling sites were established in Scirpus mariqueter salt marsh and its adjacent mudflat on the intertidal zone of Chongming-Dongtan in the Yangtze Estuary. Based on monthly trap net surveys of fishes, the characteristics of the fish assemblages in the different subhabitats, including the salt marsh and mudflat, and the monthly variations were analyzed. A total of 19 species of fishes were found belong to 12 Families. The characteristics including the dominant fish species were different in these two subhabitats. 18 species of fish were recorded in the mudflat, of which the dominant species were the Coilia ectenes, Pelteobagrus nitidus and Lateolabrax maculatus. Ten species of fish were recorded in the salt marsh of which the dominant species were the Coilia ectenes, Saurogobio dumerili, Liza haematocheila, Lateolabrax maculatus and Acanthogobius ommaturus. Pelteobagrus nitidus prefers to use the mudflat, while Lateolabrax maculatus and Liza haematocheila prefer to use the salt marsh. There was a significant difference in the monthly variation of fish abundance between the fish abundance of salt marsh and mudflat, while there was no significant difference in fish biomass. The Simpson index of the fish of the mudflat was significantly higher than that of the salt marsh, while the Margalef index and the Pielou index were lower than the salt marsh. The community can be divided into two groups: winter-spring (A) and summer-autumn (B). The abundance of fish in the mudflat and the salt marsh show a very significant correlation with the water temperature (r = 0.773, 0.830, respectively) and a significant correlation with the water salinity(r = 0.654, 0.648, respectively). The abundance of fish in mudflat and salt marsh are both significantly correlated with water temperature and salinity. The abundance of fish of the mudflat (r = 0.470, P > 0.05) is more related to the highest submerged depth than of the salt marsh (r = 0.087, P > 0.05).