Ecological Effect Evaluation Of Artificial Reef Area In Tangshan Ocean Pasture Based On Ecopath Model

In this paper,the artificial reef and non-reef ecosystem Ocean Ranch in Tangshan is taken as the research object that based on the basic principle of Ecopath,Based on three voyages,July 2016(summer),November 2016(autumn)and March 2017(spring),as well as relevant documentary data from previous years,through the use of Ecopath with Ecosim 6.5 software,The Ecopath model of Tangshan sea area is constructed,and the functional structure of ecosystem in Tangshan sea area is digitized to evaluate it.The model is mainly composed of 19 functional groups,such as Hexagramm osotakii? Sebastesschlegelii? Charybdis japonica? echinodermata? shrimps? crabs and detritus((18 functional groups in non-reef area),).The ecosystem energy of Tangshan sea area is analyzed.The process,structure,and characteristics of quantitative flow and functional changes.The main conclusions are as follows.(1)the energy conversion efficiency(EE)data of each functional group in Tangshan artificial reef and non-reef area are estimated by the established Ecopath model,and the values are in the range of 0.00-0.99.(2)the average nutritional grade of each functional group in the model was analyzed.The effective nutritional grade of each functional group was between 1.00-4.00.The energy flow of artificial reef and non-reef ecosystem in Tangshan sea area is mainly between the first and the second IV nutrient levels.According to Linderman cone diagram,the average energy conversion efficiency of each nutrient level in reef and non-reef area was 11.61% and 10.31%.(3)there are two main energy flow pathways in the artificial reef and non-reef marine ecosystem in Tangshan sea area,that is,pastoral food chain and detritus food chain.The model data were used to calculate the total energy flow of the food chain in artificial reef area,while the detritus food chain accounted for 31% of the total energy flow of the system.In the non-reef area,the total energy flow of the food chain is 66.3%,while the detritus food chain accounts for 33.7% of the total energy flow of the system.All the energy channels are pastoral food chain which accounts for a high proportion.(4)according to the 24 indexes proposed by Odum for ecosystem development and stability,three groups of index parameters were analyzed.The total primary production / total respiration(TPP/TR)of artificial reef and non-reef ecosystem in Tangshan sea area were 2.97? 3.18.Total primary production / total respiration(TPP/TR)is the main indicator of ecosystem maturity.In the early stage of ecosystem development,TPP/TR ? 1 or ? 1,in mature ecosystem,TPP/TR ? 1,(SOI)and(CI)are both the reflecting factors.The index parameters of the internal complexity of the state system.The more stable and mature the system is,the more complex the predator-prey relationship among the functional groups is.Therefore,the value of(SOI)and(CI)is positively correlated with the maturity of the system,and the larger the value is,the more stable the system is.The(SOI)and(CI)of artificial reef and non-reef ecosystem in Tangshan were 0.21? 0.22 and 0.33? 0.32.The Finn cycle index(FCI)of the artificial reef and non-reef area in Tangshan is 4.409 and 3.960 m,and the average path length MPL is 2.464 and 2.437.It is concluded that the food net structure of artificial reef and non-reef ecosystem in Tangshan sea area is simple,the ability to resist the change of external factors is poor,and the food net is still in the unstable primary stage.The release of artificial reefs makes the marine ecosystem of artificial reef area gradually stable,but because of the short time and high intensity of fishing,the marine ecosystem has a significant negative impact.It is necessary to pay more attention to the protection of fishery legal fishing operations and the resources and environment of the surrounding sea area.