Effects of marine ranching policies on the ecological efficiency of marine ranching—Based on 25 marine ranching in Shandong Province

The depletion of fishery resources and the related deterioration of marine environments has caused countries worldwide to seek solutions designed to enhance the value of fishery production and improve environmental conditions. Marine ranching has become an important means used to develop the marine economy from a human perspective while balancing the needs of marine ecology. The development of marine ranching has been particularly rapid in China. In this study, 25 marine ranching in Shandong Province, a strong province in the development of marine ranching, were investigated by collecting first-hand data and evaluating the ecological efficiency of marine ranching efforts. Then, a text database of the relevant policies related to county-level marine ranching was used as the research object. The text was quantified through a Latent Dirichlet allocation model, and three factors influencing the policy themes were obtained. Other data were collected by referring to relevant yearbooks and government reports providing information on economic development and the situations faced by enterprises. Finally, fuzzy-set qualitative comparative analysis was used to analyze the influence of conditional configuration, and the different path configurations with high and low ecological efficiency for marine ranching were studied, providing an empirical analysis for related research into marine ranching. The results showed that most of the marine ranching in the study area was still in the initial development stage, with fishery production as the main goal and lack of systematic concept, and the construction level of marine ranching in the region varied greatly. Improving the ecological efficiency of marine ranching depends on innovation and publicity, which are the key factors for the sustainable and efficient development of marine ranching. • Marine ranching policy texts were collected, and LDA model is used to categorize topics and quantify policy texts. • The ecological efficiency index system was established, and SBM model evaluated the eco-efficiency of 25 marine ranchings. • The FSQCA method was used to analyze the different paths of high eco-efficiency and low eco-efficiency. • Analyze the causes of regional differences, so as to provide suggestions for the construction of marine ranching.