Research On Macrobenthic Community Structure Colonized In Artificial Sediment

Macrobenthos spend almost all life history at the bottom of the water body. The river sediment provides direct living environment for Macrobenthos as habitat, refuge and other life activities, so river sediment materials, particle size and other factors have directly affected the community structure and distribution of Macrobenthos. Because of the complexity of natural river sediments and the diversity of particles it is very difficult to judge the impacts that a single sediment material and its diameter made on the benthic fauna community.In this paper, in order to choose the best suitable sediment material with specific particle size that Macrobenthos may survive, we studied how river sediment conditions impact on the macrobenthic community structure by conducting field surveys and field control experiments. In this study, Jinchuan North River located in Huinan County, Tonghua City of Jilin Province was selected as the research site. Selecting wood ball and stone ball as two sediment materials. The diameter of the two spheres were respectively 2, 4 and 8cm. According to certain proportion, the two sediment materials with three kinds of sediment sizes were packed into a nylon mesh with certain standard and assembled into 11 kinds of artificial sediment. The natural river sediment was replaced by the artificial sediment, then we sampled and analysed the macrobenthos in the artificial sediment. The impact of sediment material and particle size on the macrobenthos was studied. At the same time, the steps above were carried out in a parallel natural river sediment so as to explore the improving effects of artificial sediment on the river habitat.1.Totally, 57 kinds(29 families) of macrobenthos were collected during this research. Common macrobenthic populations in the test area are Heptageniidae, Ephemerellidae, Chironomidae, Tipulidae, Perlidae, Brachycentridae and Haliplidae etc.2.The wood was the most popular material among macrobenthos, followed by wood and stone mixed sediments. At 4cm, macrobenthos relax the requirement for material, which is related to wood can provide food.3.Under the same material, benthic animals tend to choose the size is 4 cm, 2、4、8cm followed. Because they can form suitable pore.4.The diversity of macrobenthos is the highest in size 4 cm wood ball, wood and stone ball mixed substrate.These two artificial substrates are very similar to peripheral natural substrate and can play a role in river habitat improvement.The data of macrobenthos obtained through fieldwork in this paper will provide theoretical basis for the recovery of Huifa River branches.