Research on Species Composition and Distribution of Large-Scale Fouling Organisms on Scallop Farming Cages Using Test Panels

From September 2006 to August 2007,a study was conducted in Liuqing River Bay,Qingdao to examine the species composition and distribution of fouling organisms on scallop farming cages using test panels.A total of 65 species were identified,and the dominant species were Ulva rigida,Enteromorpha linza,Polysiphonia urceolata,Crassostrea gigas,Mytilus galloprovincialis,Membranipora grandiella and Didemnum moseleyi.The main attachment period of the fouling organisms was from May to November.The monthly biomass reached a maximum(637.46 g/m2) in September,and the highest amount(3 121.28 g/m2) of the seasonal biomass appeared in autumn.Among semiannual panels,the second half year-panel had the maximum biomass of 5 924.57 g/m2.The annual panel biomass was 3 551.58 g/m2.The vertical distribution of the species indicated that the species were mainly algae and amphipodas on the top panels.while compared with the bottom panels,the species were mainly various fouling animals such as bivalves,ascidians,and so on.From the view point of species diversity,the number of species in summer and autumn was larger than in winter and spring,and the community evenness was the lowest in autumn.We also discussed the effects of species interdependence,season and period of submersion on the fouling organisms community,and suggested a preliminary pattern for fouling organisms community succession as follows: following the microbial film phase,the fouling organisms community began to enter a medium-term phase,and then continued to develope.The community had experienced the successive emergence and disappearance of bivalves,algae,amphipodas and hydras in this phase.Finally,on the annual panels a variety of fouling organisms formed a complex community in which the dominant species was Mytilus galloprovincialis,but it had not reached stability.