ECOLOGICAL STUDY ON THE MACROBENTHOS IN THE JIAOZHOU BAY IN 2005—2009

Based on data collected during 20 cruises from 14 sampling stations in the Jiaozhou Bay between February 2005 and November 2009,species composition,abundance,biomass,biodiversity,and secondary production of macrobenthos from the bay were studied.The results showed:1) 442 species of macrobenthos were found and identified,in which 189 were polychaete species,112 were crustaceans,81 were mollusks,22 were echinoderms,and 38 were species of other groups;the numbers of species in 2005 and 2009 were greater than those in 2006,2007 and 2008,seasonal differences in the numbers of species during 2005—2009 were small,and annual and seasonal changes were in normal ranges;2) seasonal differences of macrobenthic biodiversity indices were small;the indices were higher in the northern(inner) area than those in the southern part(close to the mouth of the bay) and outside of the bay;3) mean abundance of macrobenthos in the Bay was higher in winter and spring than those in summer and fall;the mean abundance in 2005—2009 was lower than those in 1998—2004,macrobenthic abundance in the bay decreased over time;4) the mean macrobenthic biomasses in the bay during 2005—2009 being higher than that during 1998—2004 implies that the species with large body size were increased during 2005—2009 those that during 1998—2004;5) secondary productions of macrobenthos in 2005—2009 was at similar level as those in 1998—2004,however,the culture of Philippine clam(Ruditapes philippinarum) was more important to the contribution of secondary production of macrobenthos in the bay than before;the mean secondary productions had distinct seasonal differences,i.e.,highest in spring,lowest in winter.