Economic Benefits and Improvement Strategies for Clam Marine Aquaculture in China: A Comparative Analysis of Zhejiang, Tianjin, and Shandong

In recent years, clam mariculture output in China has steadily increased. However, environmental pollution and high aquaculture intensity have led to frequent diseases and unstable economic benefits. This study analyzes field research data from clam farming in Zhejiang Province, Tianjin City, and Shandong Province, focusing on farming costs, revenue, break-even points, and net profit sensitivity. The findings reveal that (1) variable costs consistently exceeded fixed costs, particularly in seedling costs, labor, and water rental; (2) net profit and margins ranked highest in Zhejiang, followed by Tianjin and Shandong; (3) Zhejiang exhibited the lowest break-even operation rate and the largest price discrepancies; (4) sensitivity to selling prices was high across all regions, with Zhejiang showing the lowest sensitivity to variable costs. To enhance economic benefits and promote sustainable development, government authorities and industry stakeholders should focus on cultivating high-quality seeds, implementing scientific management, developing green aquaculture, and emphasizing brand development.