Study On The Restoration Technology Of Coral Reef In Daya Bay

The coral ecological environment is facing double pressures came from the natural environment change and human activities,coral reef was severely degraded.In order to alleviate the gradual deterioration of coral reef habitats,increased the number of coral reef species,increased the coverage of coral reefs,the following studies were carried out: coral reefs coverage rate and health status survey in Daya bay,selection of coral species that appropriate to repair;Carry out simulation experiment in laboratory;The development of adhesives;Study on affinity between coral and coast organisms;Launched coral transplantation accorded from the results obtained above,hope to provide reasonable suggestions for the restoration of coral reef.(1)Species diversity of the scleractinian corals were surveyed by belt transect method at Daya bay in June 2015.Survey adopted Shannon-Weaver(H')and Evenness index(J')to description the diversity of scleractinian corals.Survey accounted coverage rate,mortality rate,bleached rate of scleractinian corals,analysis characteristics that distribution of corals reefs in Daya bay.Statistical analysis shows that 54 species of scleractinian corals were recorded,among them dominant species was M.incrassate,Porites lobata,Favites abdita.The coverage rate and diversity was the highest in Xichong coast which was 55%±3% and 3.039.But the corals bleaching rate(6%±2%)was also higher in recently.Statistical analysis showed that the whole coverage rate of corals in Daya bay was 41.15%,in which had Large difference in coverage rate,corals mortality was higher in the last three years,it‘s necessary to strengthen the attention at ecological environment of Daya bay.(2)Adopted to simulate the ecological environment,to discuss the response patterns to the environment of coals,through the orthogonal experiment analyzed the response model of environment.The results indicated: environmental factors that affected the status of corals were temperature,p H,salinity,light,the intensity was secondary factor,when the temperature was 25?,p H was 8.3,salinity was 33‰,light intensity was 6000 lux,the coals status was best;Above 29?,it was the lethal temperature of corals;When the salinity above 37‰ leaded the corals bleaching and death occurred,when the salinity was below 29‰,corals tentacles would not extend out swing,accompanied by mucus of secretion covering its surface;The light intensity was the secondary factor,the physiological status of the corals had no significant effect in 5 days.Under the bad condition to live the coal,the ammonium nitrogen and phosphorus increased obviously in the water,leaded to deterioration of water quality accompanied by the stench,followed by the continuous release mucus and the discharge symbiotic zooxanthellae and finally bleached and died.(3)Transplant the corals pieces was an effective method to recover the corals reef habitat.Paper attempted to provide a kind of epoxy adhesive and preparation method,which hadaseries of characteristics,short reaction time,high gel speed,low toxicity and no pollution to environment.The experiment results indicated that when the two curing agents T31 phenolic amine curing agent and cardanol modified curing agent of ammonium in the same quality,the shear strength and gel time of E44 and T31 curing agent were more suitable,which reached 2.72 MPa and 33min;After 2 hours of adhesive gelled,shear stress increased significantly,and then improved slowly.The optimal formulation of the self-made under water epoxy resin was determined: Epoxy resin E44 accounted for 57%,phenolic amine curing agent T31 accounted for 33%,coupling agent KH560 accounted for 1.14%,toughening agent accounted for 2.85%,accelerator accounted for 1.65%,fill in total accounted for 2%.In the area of corals reef habitat restoration area with the characteristics which low toxicity and high adhesive strength of epoxy resin,which can provide a theoretical basis and technical support for the restoration of corals reef habitat in the future.(4)Concerning the corals eological effects of coral were important considerations,that are considered in the affinity between near shore organisms and corals,observation on drums that the distance between the near shore organisms and the Goniopora columna or Palythoa tuberculosa,whether harmful,weather produced attractive effects in which near shore organisms,and then classified the effect of attractive effects.The experiment results indicated that Goniopora columna and Palythoa tuberculosa produce the highest attractive effect of Charybdis feriatus(Linnaeus),while produced higher attractive effect to other arthropod;The Goniopora columna produced the highest attractive effect on Siganus oramin(Bloch et Schneider),which attractive effect was significantly higher than anemone(P<0.05),for other fish species,the attractive effect was normal;Emergence situation that anthocidaris crassispina feeding on Goniopora columna and Palythoa tuberculosa,Goniopora columna and Palythoa tuberculosa produced higher attractive effect on anthocidaris crassispina;Goniopora columna and Palythoa tuberculosa produced weak attractive effect.The results will be one of the essential for judging the location of Corals Transplantation.(5)The recipient area selection was the key to success of corals transplantation.Befor the corals transplantation that hydrological conditions,basement conditions,conitions of affinity,conition of anthropogenic activities were affinity were analyzed gradually.Corals were transplanted under ideal conditions relatively,three kinds of corals were transplanted those were Acropora humilis(Dana),Porites lobata,Platygyra daedalea(Ellis& Solander).The result indicated that corals survival rate achieved 91.8% after one year transplantion was attained at the area that the followed characteristics such as hard substrate on the coast,less strong winds and anthropogenic activites,rare corals diseases and predators,corals monthly growed in summer was 0.353 ± 0.141 cm,and growed in winter was 0.245 ± 0.118,temperature is a limiting factor,dendritic corals bleached in summer,Porites lobata,Platygyra daedalea(Ellis& Solander)bleached in winter leded to died in winter.