Study On Coupling Relationship And Influencing Factors Of Ecological And Economic System Of Mariculture In Zhejiang Province

In order to understand the relationship between ecological environment and economic development in Zhejiang Province and its main mariculture areas,the total yield of mariculture in Zhejiang Province(2005-2021)and China Fishery Statistical Yearbook(2006-2021)were used to represent the economic variables of mariculture.The pollution generated by mariculture activities in Zhejiang Province was preliminarily evaluated by pollutant production coefficient method based on the data such as pollutant production coefficient of some breeding varieties in Manual of Pollutant Production Coefficient of Pollution Sources in Aquaculture Industry for the First National Survey of Pollution Sources.After conversion,different kinds of pollutants were uniformly represented by equal standard pollution load.Using Tapio decoupling index model and decoupling stability model,the coupling relationship between ecological environment and economy of mariculture in Zhejiang Province from 2005 to 2021 was calculated.Logarithmic Mean Divisia Index(LMDI)is used to decompose logarithmic mean Divisia index in order to investigate the influencing factors of change of ecological economic decoupling elasticity index of mariculture in Zhejiang province.The following conclusions are drawn:First,from 2005 to 2021,the total amount of pollution load of standard mariculture in Zhejiang Province has reached 70,000 /a,which is the largest mariculture pollution discharge province in China.On the whole,the pollution load of standard mariculture showed an upward trend,and from 2005 to 2015,the pollution load of standard mariculture showed a fluctuating upward trend,and from 2015 to2017,it showed a rapid upward trend.The average annual growth rate was 14.7percent.From the municipal level,the pollution load of mariculture standards in Ningbo,Wenzhou,Taizhou and Zhoushan showed an increasing trend from 2005 to2021.Zhoushan has the fastest growth rate,with an average annual growth rate of7.29%,followed by Taizhou and Ningbo,with an average annual growth rate of3.64% and 3.03%,respectively.The slowest growth was in Wenzhou,with an average growth rate of 2.9%.Secondly,at the provincial level,the development of mariculture industry in Zhejiang Province is divided into two different stages,and the period from 2005 to2011 is better than that from 2011 to 2020.From 2005 to 2011,mariculture and other standard pollution decreased overall,among which,the decoupling state was strong in2005,2007 and 2010.While the total output of mariculture increased,the pollution decreased,indicating that Zhejiang focused on both economic benefits and ecological benefits in the development process of mariculture.After 2011,the ecological and economic coupling relationship of mariculture in Zhejiang Province mainly showed an expansionary negative decoupling state.That is,the increase of mariculture output is less than the increase of mariculture and other standard pollution load.There are great differences between cities in coupling relations,which can be divided into three types: expansionary negative decoupling type,coupling deterioration type and coupling improvement type.Among them,the representative city of expansionary negative decoupling is Ningbo.From 2005 to 2020,the ecological and economic decoupling of Ningbo mariculture showed a state of “expansionary negative decoupling on the whole”,and the coupling stability index was 0.52,indicating a high stability of the coupling relationship.The deterioration of coupling relationship is represented by Taizhou City and Wenzhou City,which deteriorated into expansionary negative decoupling from 2013 to 2016,that is,the growth of mariculture pollution is much higher than the growth of economic output,indicating that the two cities ignored the deterioration of ecological environment in mariculture area during the scale expansion of mariculture industry,and ecological benefits and economic benefits changed from coordination to opposition.Thirdly,through the LMDI decomposition of the decoupling index of mariculture in Zhejiang Province,the results show that the total effect formed by each driving factor from 2005 to 2020 has a certain effect on the improvement of the coupling relationship of ecological economy of seawater in Zhejiang Province,but the degree of influence is relatively weak.Among them,the largest contribution value is scale effect,followed by technology effect and structure effect.The biggest contribution is also the effect of technology.Scale effect and structure effect also play a role.