Abstract: Investigations on fish communities at the pelagic and bottom levels of mussel farming habitat were conducted in November of 2013 and February of 2014 respectively, in order to study fish assemblage differences at the two water levels. Sampling stations were located at Gouqi Island of Ma’an Archipelago, Zhejiang Province. Species composition, diversity, relative abundance, biomass and community patterns of fish at the pelagic and benthic waters of mussel farming habitat were analyzed by using diversity indices, relative fishing efficiency indices and multivariate analysis. The results showed that Mugil cephalus and Konosirus punctatus were the dominant species in pelagic waters during autumn and winter, whereas in bottom waters Sebastiscus marmoratus and Larimichthys polyactis were the dominant species during autumn, and Harpadon nehereus and Johnius belangerii were the dominant species during winter. L. polyactis was found with high abundance both in pelagic and benthic waters during both seasons. The relative catch rates in pelagic waters were higher than in benthic waters during both seasons. Higher abundance and biomass of fish were recorded in pelagic waters than in benthic waters during both seasons. The results of multivariate analysis revealed two significantly different fish composition patterns from the pelagic and benthic waters regardless of seasons. It is concluded that the mussel farming habitat can act as a floating artificial reef system. Therefore, we suggest that the floating artificial reefs can be deployed in the design of marine ranching to achieve threedimension conservation effects. Besides, artificial reefs can be set at the bottom of mussel farming area to enhance marine ranching effects.

Key words: ecosystem quality, inland river basin, Shiyang River Basin, remote sensing, geographic information system, arid area