目前,我国水产市场已告别短缺经济,养殖业由产量速度型向质量效益型转化,水产品市场已由卖方市场转向买方市场。据研究认为,提高水产养殖业效益还存在数种效益空间。一是品种效益。养鱼户所养的品种不同,其效益则有明显的差异。例如,去年7—8月间,达到商品鱼规格的鲤鱼每公斤6元,可 At present, China’s aquatic market has bid farewell to the lack of economy, aquaculture from the rate of production-based quality and efficiency into the aquatic products market has been shifted from the seller to the buyer’s market. According to the research, there are several benefits for improving the efficiency of aquaculture. First, the variety of benefits. Farmers raise different varieties of fish, the benefits are obvious differences. For example, between July and August last year, carp, which reached the specifications of commercial fish, cost 6 yuan per kilogram