The Macrozoobenthos Of Intertidal Zone In Beibu Gulf (Guangxi)

Due to the characteristic of the intertidal zone, the research on biology resourcesof this zone can be used as an important method to interpret the relationship betweennatural factors or man’sactivities and marine ecosystem. In this study, both the qualityand quantity investigation have been taken during spring (April~May) and autumn(September~October) in Beibu Gulf (Guangxi) of China. About34tansects andmore than200stations were studied. And detailed data on marine microbenthos havebeen obtained from areas of Beihai, Qinzhou, Fangchenggang (include Dongxing) andWeizhoudao island.1. A total of13phylums,178families,324generas and525species are included ininvertebrates, fish and other animals. Among these,73families,151generas and269species are attributed to the Mollusca;39families,77generas and110species to theArthropod;18families,34generas and59species to the Polychaeta;12families,13generas and15species to the Echinodermata; And36families,49generas and72species to the other invertebrate phylums and the Urochordata. Sand beachs are mostrich in species (283species), next are sand-mud/mud-sand beachs (266species);184species were recorded in rock-beaches; and mud beachs records the least species (160species).2. In spring, the average biomass is375.42g/m~2, the average abundance is369.64ind/m2; in autumn, the average biomass is194.75g/m~2, the average abundance is457.14ind/m2. The average biomass in spring is higher than that in autumn, but theaverage density is lower than that in autumn; in spring and autumn, Mollusa is themain contributor to the biomass and density. The distribution of biomass and densityare highest in high tidal zone, medium in middle tidal zone, lowest in low tidal zonein spring; and highest in high tidal zone, medium in low tidal zone, lowest in themiddle tidal zone.3. According to the diversity indexes, the environment of Beibu Gulf has beenpolluted. In spring, the best environment quality transect in high tidal zone isTiantangpo of Fangchenggang city; and in other tidal zones are Longmen town of Qinzhou city. In autumn, the best environment quality tansect in high low zone isShitoubu of Tieshangang; and in other tidal zones is Bailong of Tieshangang city.4. Based on the investigation results of this reseach, the main economic species aresix Molluscan species: Crassostrea hongkongensis, Pinctada martensii, Scapharcakaoshimensis, Tegillarca granosa, Meretrix meretrix and Haliotis diversicolor; twoCrustacean species: Metapenaeus sp and Scylla serrata; six Fishes: Mugil cephalus,Liza affinis, Liza carinatus, Siganus fuscescens, Periophthalmus modestus andScartelaos viridis; one Echinoderm species Stichopus variegatus; and two otheranimals Sipunculus nudus and ugula neritina. And according to the historical data andthe results obtained in this study, a list of species needed protection is given, whichinclude12Mollusks,18Arthropods,2Echinoderms, and one Fish.