The project will be concerned with the microbiological environment surrounding the first 35 days from hatching of all the marine fin fish species cultured in the 2 hatcheries. The project will be divided into 4 phases as follows. Standardization of methodologies for sampling procedures, analysis of material and data collection. Sampling and identification of bacteria. This phase will conclude with an open forum workshop where initial conclusions will be drawn and a programme for phase 3 will be decided. Testing for the pathogenicity of cultures, taken in phase 2, using the Laboratory for Aquaculture facilities in Belgium. The development of standard guidelines where recommendations of hygiene procedures and specific hygiene requirements for each species are given.