Rainbow trout is a major aquacultural commodity worldwide whereby any improvement of animal health and carbon footprint alleviation of the production will have a global impact. By developing novel technology to achieve climate friendly fish meat in Denmark we will reduce the carbon footprint Worldwide. Our aim is to increase, by novel breeding methods, the natural innate resistance towards the most important diseases in rainbow trout and thereby increase health, food efficiency and welfare based on a significant lower carbon emission from future fish farming. We can do this because Denmark is one of the leading countries in the World within rainbow trout farming and trout egg export. The improvements will therefore directly have impact locally and globally. Rainbow trout farming is challenged by major viral and bacterial diseases. Recently a new viral disease IHNV has spread in Denmark and it frames the urgent needs for new control strategies. Another disease, VHSV, is at present eradicated in Denmark but is still challenging trout production in other countries. Danish egg producers have important market shares in those regions and may thereby contribute significantly to mitigating problems there. Climate friendly and effective control methods are urgently needed and here marker assisted breeding is the optimal and climate friendly solution. We will target the viral diseases caused by IHNV, VHSV, and IPNV, and bacterial diseases furunculosis and vibriosis.