Following a preliminary investigation in 1977, the Department of Fisheries & Forestry carried out an intensive multi-disciplinary survey of Mulroy Bay in the summer of 1978. The results of this "blitz" survey, when evaluated, formed the basis of more extensive research in the North Water during 1979. This North Water programme was expanded in 1980, as part of the Department's contribution to a co-operative research programme on Mulroy Bay organised in conjunction with the National Board for Science & Technology. This included a hydrographic survey, specially commissioned by the Department, to produce a detailed bathymetric chart of the North Water. This was made available free of charge to interested individuals and groups in the locality. The 1980 research results were presented at a seminar in January 1981 at the Department's Fisheries Research Centre, which was organised in order that the data obtained could be discussed and evaluated by the individuals and agencies involved in the field programme. This Fisheries Leaflet is a summary of the papers read at that seminar, by staff of the Fisheries Research Centre.