The Ecological Study Of Macrobenthos In The Waters Around Changdao Islands

Based on the samples collected during November2012, February, May andAugust2013, which represented autumn, winter, spring and summer respectively, thespecies composition, abundance, biomass, dominant species, biodiversity, secondaryproduction and community structure of macrofauna were analyzed. The relationshipbetween macrofauna community structure and the environment factors was alsostudied. The results provide baseline for ecological study of macrobenthos, andcomplemente the investigation about macrobenthos in the waters around ChangdaoIslands. The main results of this research are as follow:1. In the intertidal areas, a total of87macrobenthos species were identified,including Mollusca (35species), Annelida (28species), Arthropoda (20species),Platyhelminthe (1species), Nemertinea (1species), Echinodermat (1species) andCoelenterata (1species). The largest number of species was collected in autumnamong the four seasons. In the subtidal waters, a total of164macrobenthic specieswere identified, including Annelida (82species), Arthropoda (39species), Mollusca(29species), Echinodermat (9species), Coelenterata (2species), Platyhelminthe (1species) and Nemertinea (1species). The largest number of species was collected inwinter among the four seasons.2. In the intertidal areas, the total average abundance of the four cruises was1499ind./m2, of which the abundance of Polychaeta was1170ind./m2; Nemertineawas226ind./m2; Mollusca was53ind./m2; Arthropoda was23ind./m2and othergroups was26ind./m2. In the subtidal areas, the total average abundance of the fourcruises was919ind./m2, of which the abundance of Polychaeta was601ind./m2;Mollusca was170ind./m2; Arthropoda was92ind./m2and other groups were56ind./m2. 3. In the intertidal areas, the total average biomass of the four cruises was1.01g/m2, of which the biomass of Polychaeta was0.76g/m2; Echinodermat was0.12g/m2;Arthropoda was0.06g/m2and other groups was0.058g/m2. In the subtidal areas, thetotal average biomass of the four cruises was18.01g/m2, of which the biomass ofPolychaeta was7.36g/m2; Mollusca was4.85g/m2; the other groups were3.33g/m2and Arthropoda was2.48g/m2.4. In the intertidal areas, the dominant species were Heteromastus filiformis,Pseudopolydora paucibranchiata, Goniada japonica, Phylo ornatus and Nemertinea.In the subtidal areas, the dominant species in spring and summer were Lumbrinerisheteropoda, Terebellides stroemii, Lygdamis giardi, Chaetozone setosa andCtenopleufa ludwigc. The dominant species in autumn and winter were Moerellairidescens, Pherusa cf. bengalensis, Chaetozone setosa, Marphysa sanguinea andLumbrineris latreilli.5. The secondary production of macrobenthos in the intertidal areas was0.73g(AFDW)/(m2.a)，and the average P/B value was4.76. The secondary production ofmacrobenthos in the subtidal areas was6.37g(AFDW)/(m2.a)，and the average P/Bvalue was2.04.6. In the intertidal areas, the highest values of species number, richness index,Pielou’s evenness index and Shannon-Wiener diversity index were found at Site A3.In the subtidal areas, the largest numbers of species were found at Sites CD28andCD24. The highest value of richness index was found at Site CD24. The highest valueof Pielou’s evenness index was found at Site CD30. The highest values ofShannon-Wiener index were found at Site CD24.7. According to the present study, macrofauna communities of the intertidalareas can be grouped into6types of communities. The groups were mainly influenced by the season. Those of the subtidal areas can be grouped into7types of communities.The groups were mainly influenced by the season and sediment type.8. In the intertidal areas, the best match environment factors for communitystructure were sediment sorting coefficient and Chlorophyll a content. In the subtidalareas, the best match environment factors for community structure were the watertemperature, sediment median diameter and Phaeophorbide content.