Abstract:

Research on the biodiversity of mangrove ecosystems should include not only the plants but other components, such as the macrobenthos. In order to understand the response of the macrobenthos to a mangrove habitat with high organics and nutrients, we compared the mangrove and non-mangrove macrobenthic communities, and analyzed their spatial-temporal distributions in these two habitats from April 2006 to January 2007 in Tong’an Bay, Fujian. Six sampling stations were set in Tong’an Bay, four of them (FL1, FL2, XA-A and XA-B) were in the mangrove habitat, the other two (FL3 and XA-C) were in the non-mangrove habitat. An analysis of sediment properties showed that total organic matter (TOM) of the three sampling stations at Fenglin exceeded the critical threshold, namely 3.4%, and TOM in mangrove stations was higher than in the non-mangrove ones. A total of 91 macrobenthic taxa were obtained from the six sampling stations in Tong’an Bay, including 77 and 67 taxa from the mangrove and non-mangrove habitats, respectively. Mean macrobenthic densities in the mangrove and non-mangrove habitats were 4,445.8 inds/m²and 1,707.2 inds/m², respectively. Mean biomasses in the mangrove and non-mangrove habitats were 51.1 g/m² and 94.6 g/m², respectively. The results of an independent-samples t-test showed that mean density and mean biomass were significantly different in the two habitats. The present study revealed that the mangrove habitat has a positive influence on the Oligochaeta, such as Limnodriloides sp., that thrives in the high TOM sediments. Because of the shorter inundation period in the mangrove habitat, however, free-living molluscs and crustaceans preferred the non-mangrove habitat. Other sediment properties such as interstitial salinity and median particle diameter also affected the macrobenthic community.

Key words: macrobenthos, community, mangrove, Fujian