黄海冷水团大西洋鲑（Salmo salar）养殖容纳量研究

China is the largest marine aquaculture country in the world. However, a series of problems exist in the aquaculture industry of China, including the unreasonable compositions of the aquaculture products and the unsustainable aquaculture modes. The major performances of such problems include: (1) The production of high-quality marine fish is too low to meet the increasing demand of the consumers for the marine protein; (2) The main aquaculture modes in China include land-based factory farming, coastal and pond farming, and inshore aquaculture. Such aquaculture modes have led to a series of problems, including space competition between aquaculture and other industries, ecological loss, disease risk and the problem of quality and safety of seafood. As a consequence, extension of the mariculture space from inshore to offshore waters has been the must tendency for the sustainable development of aquaculture in China. There is a large-scale cold water mass in the Yellow Sea and the temperature, dissolved oxygen and other conditions are suitable for the farming of Atlantic salmon Salmo salar. The present project is aimed to study the metabolism of nitrogen and phosphorus of Atlantic salmon under different aquaculture conditions and the effect of salmon farming on the water and benthic conditions of the Yellow Sea cold water mass. Based on such studies, the aquaculture capacity of salmon in the Yellow Sea cold water mass is accessed. The results of the present project will provide scientific data for the development of offshore healthy and efficient aquaculture technologies of salmon aquaculture in the Yellow Sea cold water mass.

我国是世界海水养殖大国，但是我国的海水养殖存在产品结构不合理，养殖模式不可持续的严重问题。主要表现在：（1）优质海水鱼类产量过低，不能满足居民日益增长的对优质海洋蛋白的需求；（2）我国的海水养殖以陆基工厂化、滩涂池塘、浅近海养殖为主，产生了产业发展空间冲突、生态损失、病害风险、水产品质量安全等一系列问题。因此，海水养殖从近岸向离岸拓展，发展优质海水鱼类规模化养殖生产，已成为我国海水养殖可持续发展的必然选择。我国黄海海域存在巨大的黄海冷水团，其水温、溶解氧水平以及其它水文、水质指标为开展深远海优质鲑鳟鱼类养殖提供了得天独厚的条件。本项目在充分研究鲑鳟鱼类的优质品种大西洋鲑在不同养殖条件下溶解氧需求以及氮磷营养盐代谢过程的基础上，结合大西洋鲑养殖活动对黄海冷水团海域的水文水质和底质环境的影响，科学测算黄海冷水团养殖海域大西洋鲑养殖容纳量，为发展黄海冷水团大西洋鲑绿色高效养殖提供科学依据。

本项目研究了不同养殖条件和环境条件对鲑鳟鱼类碳、氮和磷营养要素收支的影响，调查了黄海冷水团海区水文和水质条件的季节性变化，评估了鱼类养殖生产活动对水体和底质环境的影响，进而采用Delft3D软件评估了黄海冷水团海区鲑鳟鱼类养殖容量。研究结果表明，温度和规格都会对硬头鳟的营养要素收支产生显著影响，但温度和规格的交互效应对硬头鳟的营养要素收支影响不显著。温度16°C处理组，硬头鳟的摄食率和碳、氮、磷营养要素的生长余力显著高于其他温度处理组；非线性回归结果表明，硬头鳟摄食和生长的最适宜温度约为15°C。硬头鳟单位体重的摄食率和碳、氮、磷营养要素生长余力随硬头鳟规格的增加而降低。一组（10个）网箱在工程允许的范围内平行于流速方向呈两列或三列紧密排列时，其溶解氧和非离子氨浓度均符合本研究规定的水质标准（溶解氧浓度大于5 mg/L，非离子氨浓度低于0.02 mg/L）；当两组网箱沿流速方向间隔1 km以上排列时即可避免组间的互相影响。养殖区的生产性养殖容量应为每组网箱在工程允许的范围内紧密排列，组间距为1 km。养殖周期内四种养殖规模下养殖区内的各水质指标均符合二类海水的水质标准；但当网箱布放数量到达80个时，受养殖活动影响，9月下旬养殖区外的溶解氧水平将降低至6 mg/L以下，由一类海水降为二类海水。据此认为60个网箱即为养殖区的生产性养殖容量。研究结果可为确定鲑鳟鱼类海水养殖的合理密度提供科学依据，促进深远海养殖产业高效健康可持续发展。