The marine ecosystem services values for China based on the emergy analysis method

The purpose of this research is to acquire knowledge and understanding of the value of marine ecosystem services in China's coastal regions. This evaluation involved combining existing research results, based on the theory of ecosystem services and emergy analysis, estimating marine ecosystem services values in 11 coastal provinces and cities for each year from 2005 to 2014, and analyzing the changes in marine ecosystem services values over time and across regions. The results showed that the values had in general increased during the time the study was conducted, and that Hainan, Guangdong, and Shandong accounted for most of the value. Applying the Theil index to analyze the regional differences of China's coastal marine ecosystem services values, we found that these disparities had shrunk; intra-region disparities were the primary cause of this shrinkage, but the developments of marine ecosystem services values of both intra- and inter-regions were unbalanced. Changes in the marine ecosystem services structure in China's coastal regions from 2005 to 2014 were analyzed using the information entropy theory. Over time, the information entropy and equilibrium degree of China's coastal marine ecosystem services structure consistently showed a fluctuating uptrend; across regions, the information entropy of the marine ecosystem services in the 11 coastal provinces and cities had larger discrepancies. Our results reveal emergy analysis is a helpful method for assessing marine ecosystem services, and our database can serve as a basis for more studies the future. Our research has also revealed the problems existing in the development of marine ecosystem services in China, such as the imbalance in the development of marine ecosystem service values between regions and the differences in the degree of development of various services, which is crucial to the future development of the ocean.