Preliminary Evaluation Of Artificial Reef Around RizhaoQiansan Island On The Enhancement Of Fishery Resources

Artificial reefs are artificial facilitie used to improve the marine ecological environment and restore the fishery resources. Artificial reef project of RizhaoQiansan island is one of the six artificial reef projects belong to fishery resources restoration planning in Shandong Province. The artificial reefs were built from 2005 to 2007 years and cover an area of 86 hectares. The total investment is about 25.5 million yuan,70000cubic meters stone blocks,129000 cubic meters concrete structures,220 retried boats and 13 large steel tugboats were used. In order to explore how were the fishery resources affected by the artificial reefs around the RizhaoQiansan island, the triple fixed gill net survey and the cage net survey were carried out in the artificial reefs area and control area around RizhaoQiansan island from September,2012 to August,2013.Based on the survey results, the number of fisheryspecies and the composition of dominant species in artificial reef area and control area were analyzed and compared.Biological community diversity was explained by Margalef species richness index (D), Shannon-Winener diversity index (H) and Pileou uniformity index (J’). Fishery resources density was explainedby CPUE of gill net. We got the following results through data analysis.1. The triple fixed gill net survey indicated the number of fishery species in reef area were 1.71 times more than those in control area. The fish species in reef area were 2.38 times more than those in control area. The species of shrimp,crab,echinodermata,cephalopod in reef area were more than those in control area. The species richness index and diversity index in artificial reef area were higher than those in control area.The dominant species of artificial reef area were more stable than those of control area.CPUE and resources density in artificial area were higher than those in control area.2. The cage net survey indicated the number of fishery species in reef area were 1.35 times more than those in control area. The fish species in reef area were 1.44 times more than those in control area. The species of shrimp.crab in reef area were more than those in control area. The species of control area also appeared in ree area.The species richness index and diversity index in artificial reef area were higher than those in control area, except the diversity index of artificial area were lower than those in control in May 2013.The resources density in artificial area were higher than those in control area except Jan.2013.3. The comprehensive survey of cage net and triple fixed gill net indicated the number of fishery species in reef area were 1.64 times more than those in control area. The fish species in reef area were 1.92 times more than those in control area. The species of shrimp,crab and echinodermata in reef area were more than those in control area. The species of control area also appeared in ree area.The species richness index and diversity index in artificial reef area were higher than those in control area, except the diversity index of artificial area were lower than those in control in May 2013 CPUE and resources density in artificial area were higher than those in control area.In conclusion,the artificial reefs were beneficial for the increase of fishery resources,the improvement of structure and biological community diversity and the obvious aggregation effect of fishery species.The research methods and results of this paper could provide theoretical support for building and effect evaluation of the artificial reefs.