闭式循环水养殖技术发达国家基本上不再发展耗水多的流水养鱼业，而是重点开发闭式循环水养殖设备，进一步改进水处理技术，减少日换水量。另外，海上流动生产的船舶型、海上平台型流水式养鱼设备等在西欧和北欧国家也将有一定程度的发展。 纯氧增氧技术近年来，丹麦、德国等一 Closed-loop water aquaculture technology developed countries are basically no longer develop water-intensive water fish farming, but rather focus on the development of closed-loop water aquaculture equipment to further improve water treatment technology to reduce daily water exchange. In addition, the production of sea-based ships, offshore platform-type water-based fish farming equipment in Western Europe and northern European countries will also have a certain degree of development. In recent years, Denmark, Germany and other one