The Economies of Scale of Turbot Industrial Running Water Aquaculture System in China: A Case from Shandong Province

China is the most important production contributor of farmed turbot in the world. The economies of scale of turbot farming industry in this significant country haven't been studied in detail. In this study, based on survey data from the largest farming area of this species, Shandong Province of China in 2015, DEA (Data Envelopment Analysis) was used to assess the turbot culture efficiency of different farming scales. All these turbot farmers used industrial running water aquaculture system, which provided over 90% of China's total production of this species. The results showed that (1) the overall efficiencies of different farms increased with the enlargement of their farming scale and (2) the efficiency of each farming scale could still be improved. Given the outputs unchanged, a reduction in inputs can improve the utilization efficiency of feeds, electricity and labor, and reduce the irrational exploitation of land and groundwater resources; this change would not only increase economic benefits but also protect natural resources, thereby achieving the harmonious development of the economy and environment.