The Study Of Natural Bait Structure And Water Quality Dynamic Change Of Underground Tube Eco-farming Conservation System

Mangrove are the important intertidal zone protection forest,at the same time, it is important to region economy of seafood.The development of Mangrove ecological aquaculture is to solve optimal solution of mangrove protection and development.The investigation about how natural bait animal enter the system in the process when"Underground tube eco-farming conservation system" running,and Combinate the investigation about breeding body growth dynamics change and the analysis about system dynamic change of water quality, is to have further understanding of the breeding mechanism and operating mechanism,and provide the comprehensive theoretical research for the next step about the technical renovation transformation, upgrade.The main results are as follows:The natural bait survey found that34kinds of natural bait animals,which belong to4,18families,31genera and34species of5classes.The fish and crustaceans in bait animals have the highest abundance,they are the dominant species of bait animals,the dominance is signifiicantly.Synechogobius ommaturus and Exopalaemon carinicauda constitute the main body of natural bait of system,and they are the major contributors of bait animal individual number and weight.Exchange during June survey about bait animal number and other survey period there is an extremely sigrdficant difference between, and quality have significant difference between them.Thereis no significant difference between other survey period.The exchange between bait animals quantity and weight correct by standpipes were no significant difference. The quantity and weight of bait animals correct by management window is no significant difference between windows; Between various period time of investigation, the bait animals’ quality exist significant difference between management windows.Bait animals have no significant change on the biodiversity index, individual sample point material between species richness and diversity index exists significant differences.The Bostrichthys sinensis’body length and weight grew most rapidly during July and August.The growth inflection point of body length is17.77cm, and the inflection point’s time is the79d.The growth inflection point of weight is81.39g, and the inflection point’s time is the83d.Cultivation ultimate survival rate is94.23%,the95%confidence interal of natural bait during breeding cycle is135622.30g to318202.63g, accounted for4.62%-10.23%of total bait, mixed bait coefficient is2.00-2.13.The system’s water quality drop after a tidal cycle.After15d, most water in system only reach the standard seawater class Ⅲ, part of the them fall serious, only reach standard seawater class IV.Principal Component Analysis results show that the main factor of water quality fall is the concentration of dissolved oxygen, ammonia nitrogen, inorganic nitrogen and inorganic phosphorus,the main pollution is the organic waste from breeding process.Concentration of dissolved oxygen is the main factor of restricting water quality of the system.