据美国商业部的数字表明,目前美国水产养殖年产量已超过25万吨,发展最迅速的种类是鲶和鲑。 1980年,美国鲶的产量还不足35000吨,1985年超过123000吨。鲑的产量在同期也从3450吨增至38320吨,鲑的网箱养殖正在稳步发展,养殖的主要种类是太平洋鲑,养殖 According to the U.S. Department of Commerce, the annual aquaculture production in the United States now exceeds 250,000 tons, the fastest-growing species being catfish and salmon. In 1980, the production of the United States catfish was less than 35,000 tons, more than 123,000 tons in 1985. Salmon production also increased from 3,450 tons to 38,320 tons over the same period, and salmon cage culture is steadily growing with the main species being Pacific salmon, farmed