三、种苗生产存在的主要问题1.低值种类较多，产值较低我国水产养殖产量占世界总产量的三分之一。其中，养殖产量占世界养殖总产量的67％，但产值仅占45％。挪威30万吨大西洋鲑产值相当于我国300万吨产值。2.人工培养培育良种少，过度依赖野生种虽然海水养殖由传统的两大藻类四 Third, the main problems of seed production 1. Low-value species are more low value of aquaculture production in China accounted for one-third of the world’s total output. Among them, aquaculture production accounts for 67% of the world’s total aquaculture production, but the output value accounts for only 45%. Norway 300,000 tons of Atlantic salmon output value equivalent to 3 million tons of output value. 2. Artificial cultivation less breeding, over-reliance on wild species Although mariculture by the traditional two large algae four