Zhang, L. and Cai, S., 2020. Theoretical methods and applications of marine economy and sustainable marine development. In: Yang, Y.; Mi, C.; Zhao, L., and Lam, S. (eds.), Global Topics and New Trends in Coastal Research: Port, Coastal and Ocean Engineering. Journal of Coastal Research, Special Issue No. 103, pp. 581–585. Coconut Creek (Florida), ISSN 0749-0208.

Together with the rapid development of the maritime economy (ME), the extent and depth of exploitation of marine resources is also increasing and the pressure for sustainable use of marine resources is increasing. To this end, this paper proposes the theoretical methods and applications of marine economy and sustainable (MEAS) marine development. This paper proposes the DEA evaluation method. First, the characteristics, structure, and construction procedures and methods of the evaluation index system of complex systems are studied. The construction methods and principles of the marine economic composite system evaluation index system were discussed, a systematic evaluation index system was established, and an emergy analysis and comprehensive evaluation DEA model for MEAS ocean development were proposed. The research is carried out through the application of examples. This paper finds that China's marine technology investment was valid for DEA in 2014, 2018, and 2019, and that it was non-DEA valid from 2015 to 2018. The DEA effectiveness coefficient values were 0.976489, 0.619141, and 0.808176, which indicates that in 2018 and 2019, science and technology played a significant role in the added value of China's marine industry and the achievement of scientific research results, and the rest of the years were not effective.