Studies on the Macrobenthic Diversity in the Water Around Gulei Peninsula of Fujian in Spring

Abstract:

Macrobenthic organisms are widely distributed in the world and are efficient bio-indicators of environmental change because of their limited mobility. They are also an important part of the basic data in environmental assessment. In this study we evaluated the current macrobenthic diversity and their regional difference in the water around Gulei peninsula, and we also discussed how this distribution pattern was formed. Before the petrochemical production in Gulei national petrochemical base, 27 stations were surveyed in April and May 2011. Twelve stations were located in the east and 15 were in the west of the peninsula. According to the data on totally 145 species, we found there were 69 polychaetes, 20 molluscs and 29 crustaceans, which were the dominant taxa. Macrobenthic species were rich in the water but the number of species was low with an average of 10. The number of species ranged from 2 to 23 at different stations. The occurrence frequency and the dominance index of most species were also quite low. The density and biomass were (111±200) ind/m2 and (14.79±22.03) g/m2 respectively. Higher density and biomass mostly appeared to the west of Gulei peninsula. The average Shannon-Wiener index and Margalef’s species richness index were 2.064 and 2.847 respectively, which were low because the number of species was below 10 at more than half of the stations. The macrobenthic diversity and density in the inner Dongshan Bay were much higher than in the bay mouth and in the east side of Gulei peninsula. Compared to other bays in Fujian, the study area had higher macrobenthic diversity but lower density and biomass. These results suggested that the diversity of macrobenthic organisms in the water around Gulei peninsula was related to the complexity in the sediments. Sandy sediments that were typical in the water were not suitable for the inhabitation of many species at the most stations, which resulted in low species number and density. Furthermore, there was a change in the composition of dominant species compared to the previous data.