Changes in community structure of macrobenthos in Suzhou Creek, Shanghai, China

Investigations were conducted of community structure of the macrobenthos in the Suzhou Creek from April to December in 2005, covering density, biomass, diversity and dominancy of species, and comparison made with the data of macrobenthos collected in 1999, 2001 and 2003, in order to explain changes in community structure of the macrobenthos in the Suzhou Creek. Results show that from 2001 to 2005, species diversity of the zoobenthos decreased from 14 to 8, average density decreased from 34 445.1 m^-2 in 1999 to 3 746.6 m ^-2 in 2001, and then rose up to 22 770.8 m^-2 in 2005, while biomass decreased from 285.33 g · m^-2 to 31.78 g · m^-2 from 1999 to 2005. From 2001 to 2003, Shannon-Wiener diversity index decreased from 1.20 to 0.49, and Pielou index from 0.67 to 0.40. Dominant species at sites Zhaotun and Huang-du changed from Bellamys aeruginosa in 1999 and 2001 to Limnodrilus hoffmeisteri in 2003 and 2005, while the dominant species at sites Beixinjing and Zhejiangluqiao remained unchanged. According to the changes in community structure of the zoobenthos, the restoration of zoobenthos in the Suzhou Creek can be divided into two phases:fast restoration phase in 1999 and 2001, and slow restoration phase in 2003 and 2005.