Assessment of fish health and welfare under different dietary and abiotic conditions

Previous trials have demonstrated that the phosphorus levels in fish diets reduced to 50% of their required levels did not effect fish growth but bones remain unmineralized. However, the phosphorus deficient un-mineralized bone can be re-mineralized without tissue alterations. It gives us opportunity to reduce dietary phosphorus levels in fish diets which is a finite source with limited availability especially in present scenario and uses extensively in agriculture and aquaculture diets. However, oversupply of phosphorus in diets did not show any superior results in our previous trials but it results in water pollution, eventually leads to anoxic zones in water that lead to fish deprived of oxygen, and eventually dies. In this trial, fish will be fed 20% reduced phosphorus levels than recommended levels by replicating hatchery conditions in water tanks. A reduction in dietary phosphorus levels will be achieved for normal bone mineralization which will not only save the cost but also reduce its negative environmental impacts in the form of eurtrophic zones in water. Thus we would like to test the influence of dietary phosphorus under common farming conditions on fish health and welfare in 1200 Atlantic salmon parr. To document the dietary impacts on fish health and welfare, live animals must be used, however, the number used in the experiment is limited to that which will provide significant differences between control and experimental groups (assuming an alpha value of 0,05 and a power of 0,8).